Paul J Hetzler's Posts - CornellForestConnect2024-03-28T21:59:38ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429https://storage.ning.com/topology/rest/1.0/file/get/1591223011?profile=original&xn_version=202403260758&width=48&height=48&crop=1%3A1&xj_user_default=1https://cornellforestconnect.ning.com/profiles/blog/feed?user=2cj2wlf73fonx&xn_auth=noIt Takes a Village to Raise a Foresttag:cornellforestconnect.ning.com,2023-05-23:6448444:BlogPost:1161122023-05-23T19:06:24.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>It Takes a Village</p>
<p>The decline in children’s mental health during COVID-19 restrictions is a poignant reminder that we’re a social species, hardwired for contact with others. The saying “It takes a village to raise a child” is spot-on. Whether a literal village or a caring community within a city, we all – children especially – need regular interaction with peers and supportive mentors.</p>
<p>In a different sense, but true nonetheless, it takes a village to raise a forest. In this…</p>
<p>It Takes a Village</p>
<p>The decline in children’s mental health during COVID-19 restrictions is a poignant reminder that we’re a social species, hardwired for contact with others. The saying “It takes a village to raise a child” is spot-on. Whether a literal village or a caring community within a city, we all – children especially – need regular interaction with peers and supportive mentors.</p>
<p>In a different sense, but true nonetheless, it takes a village to raise a forest. In this case, the “village people” include mice, birds, and squirrels. When we think of forests, we naturally picture trees – probably large, mature ones. But even big, old trees rely on some pretty humble villagers. Forests are complex, elegant systems that could not exist without a little help from their friends.</p>
<p>According to the US Department of Agriculture, oaks and hickories play a keystone role in hardwood forests throughout southeastern Canada and the eastern United States. But nuts and acorns aren’t so good at wafting on the breeze to disperse. They need a hand, or more likely, a paw or beak, to spread far from the trees that produced them. Everyone fares better outside the shadow of their parents.</p>
<p>It's no surprise that grey squirrels, including their black melanistic subgroup, are critical to the survival of nut-bearing trees. As humorist Will Cuppy wrote in his 1949 book <em>How to Attract a Wombat</em>, “Squirrels have been criticized for hiding nuts in various places for future use and then forgetting the places. Well, squirrels do not bother with minor details like that. They have other things on their mind, such as hiding more nuts where they can’t find them.”</p>
<p>Before learning stuff like “facts” about squirrels, I assumed they forgot most of their buried nuts. However, in controlled trials done at Princeton University in 1990, it turns out grey squirrels recover about 90% of them after 12 days.</p>
<p>A side-effect of large wooded tracts getting fragmented is that red squirrels, which are better suited to patchwork forests, are driving their grey cousins out of the woods. I assume this explains why grey squirrels have taken to chewing the faces off Halloween pumpkins instead of reforesting the landscape. But red squirrels, native to pine / fir / spruce habitats, cache most acorns and nuts in above-ground in “larders,” and plant very few hardwoods.</p>
<p>Mice also collect tree seeds, and inter some for later use; thus helping to regenerate maples, American beech, pine, and other species. Apparently, the impact of each mouse on forest health depends on its temperament. When I see a mouse indoors, I just want it out – I don’t wonder if it has a nice disposition.</p>
<p>Pioneering studies at the University of Maine have documented a range of personality types among mice and their cousins the meadow voles and pine voles (not to be confused with moles, which are carnivores). In a nutshell – so to speak – timid mice and voles don’t travel far to bury seeds, and they tend to pick sites conducive to seed germination. Brash rodents go farther afield, but often hide their seeds in spots that are less tree-friendly. Each strategy aids the forest in different ways.</p>
<p>While acorns and nuts can’t float on the wind, they sure do fly. According to a November 12, 2022 CBC news report, drones will soon be planting trees in western Canada. But that’s cheating. Blue jays have been doing this for thousands of years. In his 2005 book, <em>Oak: The Frame of Civilization</em>, arborist and nature-writer William Bryant Logan says blue jays forget more of the acorns they stick in the ground than squirrels do. That’s what happens when you have a bird brain, I guess.</p>
<p>Without good regeneration, a forest is doomed. But there are other key elements to a robust and resilient forest, such as natural pest control. In a diverse and vibrant forest “village,” insects that harm trees are usually kept in check through an array of natural controls. Birds, predatory insects, viruses, and fungi are just some of the agents that help keep pest populations in balance.</p>
<p>Quite recently it was shown that bats may be the most crucial pest-control player of all. Bat caves are for hibernating bats, and perhaps a crime-fighting superhero with a bat fetish. But during the summer, bats are happy campers in the woods, hanging out under loose tree bark in the daytime. An October 30, 2022 article in the journal <em>Ecology</em> summarized the first-ever US field study on the specific role bats play in forest health.</p>
<p>Elizabeth Beilke, a researcher at the University of Illinois at Urbana-Champaign, and Joy O'Keefe, a wildlife extension specialist with the Illinois Department of Natural Resources, conducted the 3-year study “in the central hardwood region of the United States,” as they cryptically say in their article. The 20 large, mesh-covered enclosures they made were opened at dawn and closed at dusk so bats could not enter. Each year from 2018 to 2020, insect damage to tree seedlings in the covered plots was compared with damage in 20 same-size control plots open to bats.</p>
<p>Their findings are clear: “Insect density was three times greater on seedlings in bat-excluded versus control plots. Additionally, seedling defoliation was five times greater with bats excluded…” Beilke and O’Keefe believe bats are imperative to North American forest ecosystems, possibly more so than any other animal.</p>
<p>It was bound to happen: every village has its overachiever.</p>
<p>This article first appeared in <em>The Saturday Evening Post</em>.</p>Maple Sap Runs On Gastag:cornellforestconnect.ning.com,2022-03-19:6448444:BlogPost:1120102022-03-19T10:54:24.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Some foods give us gas, but gas is what ultimately gives us maple syrup. If not for gas bubbles in the wood, sap wouldn’t flow. Who knew maple trees were CO<sub>2</sub> powered?</p>
<p>A mere two decades ago, arborists were at a loss to explain what caused maple sap run. We'd typically mumble something about transpirational vacuum in the canopy before changing the subject. Everyone knows sap runs when warm days follow freezing nights. But it wasn’t until recently that the mechanism behind…</p>
<p>Some foods give us gas, but gas is what ultimately gives us maple syrup. If not for gas bubbles in the wood, sap wouldn’t flow. Who knew maple trees were CO<sub>2</sub> powered?</p>
<p>A mere two decades ago, arborists were at a loss to explain what caused maple sap run. We'd typically mumble something about transpirational vacuum in the canopy before changing the subject. Everyone knows sap runs when warm days follow freezing nights. But it wasn’t until recently that the mechanism behind sap flow was better – although still not perfectly – understood.</p>
<p>Aside from maples, few species have a spring sap run. Birch and butternut do, but their roots generate pressure that forces sap upward. In contrast, maple sap flow is due to how its wood reacts to freeze-thaw cycles. Wood, or xylem, has vessel cells to carry liquids, and fiber cells for strength. Unlike most trees, maple fiber cells are partially filled with carbon dioxide and other gases, which can dissolve in sap.</p>
<p>At night, gases in fibers shrink as they cool, eventually dissolving into sap in the vessels. This drops the tree’s internal pressure, creating suction that draws sap from the roots. As daytime temperatures rise, gases bubble out of solution and expand, increasing internal pressure and forcing sap out tap holes at between 103 and 276 kPa.</p>
<p>Rather than flowing up from the roots and out the tap as was once thought, sap flows down from the crown (plus some lateral flow) toward a tap. When a warm day follows a sub-freezing night, sap may run from a few hours to several days, depending on the tree and barometric pressure. If it’s warm all night or freezing all day, sap won’t run.</p>
<p>Although sugar and black maples are most commonly tapped, producers also use silver and red maples when available. Even the humble Manitoba maple can be tapped. Maple sap is 2-3% sucrose on average, though this can range from below 1 to over 10%. In addition, sap contains organic acids, amino acids and minerals which contribute to maple’s flavour.</p>
<p>If great taste isn’t enough reason to use syrup, consider its health benefits. A 100-gram serving of maple syrup provides over 100% of the recommended daily amount of manganese and vitamin B-2, and it’s a significant source of magnesium, zinc and calcium. In 2016, Toronto-based researchers announced they’d identified a compound in maple syrup that inhibits clumping of beta-amyloid brain proteins, which may help prevent Alzheimer’s disease.</p>
<p>The freeze-thaw, dissolved-gas, pressure-differential explanation of sap flow has some holes, though. While the mechanism should work with pure water, sap only flows if it has a minimum level of sucrose. Flow should also happen in all xylem tissue, not just the living sapwood, but that’s not the case either. So the mystery of sap flow continues.</p>
<p>Recently, maple producers have been branching out into value-added products like maple candy. Another item is bottled, pasteurized and, of course, carbonated maple sap. What goes around, comes around, it seems.</p>
<p><em>ISA-Certified Arborist Paul Hetzler never shakes pop cans or maple trees before opening.</em></p>Think Spring, Think Tree Plantingtag:cornellforestconnect.ning.com,2022-02-16:6448444:BlogPost:1116832022-02-16T19:21:55.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Looking for a way to enhance property value, save energy costs, boost mental health, and help the planet in one simple, low-cost step? Yeah, me too. Let me know if you think of something.</p>
<p>Seriously, though, a few well-placed trees in one’s yard typically add at least 5% to a property’s value. Having large older specimens (of trees, I mean) around the house can push that figure close to 20%. In terms of energy savings, deciduous trees on the southern and western sides of a house tend…</p>
<p>Looking for a way to enhance property value, save energy costs, boost mental health, and help the planet in one simple, low-cost step? Yeah, me too. Let me know if you think of something.</p>
<p>Seriously, though, a few well-placed trees in one’s yard typically add at least 5% to a property’s value. Having large older specimens (of trees, I mean) around the house can push that figure close to 20%. In terms of energy savings, deciduous trees on the southern and western sides of a house tend to slash cooling costs by roughly one-quarter.</p>
<p>Trees enrich our lives in subtle ways too. We recover from surgeries and illnesses more rapidly if there are trees in view out our window. Crime rates drop when neighborhoods are planted with trees. Plus, lying under trees might cure acne. OK, not sure on that one.</p>
<p>Giving genuine thought to site and species selection is critical to the long-term survival of landscape trees, and right now is an ideal time to plan for success. Any given location will be great for some trees, yet awful for others. Poor drainage, exposure to deicing salt, restricted root area, overhead wires, and shade are but a few possible constraints. Any these attributes alone can lead to the decline and eventual death of certain trees.</p>
<p>On the other hand, that there are species and cultivars able to mature and thrive no matter what limitations a site has. “Right tree, right place” is an arborist mantra. We have others, like “please clean the dog poop before I come look at your tree,” but I digress.</p>
<p>The point is that sometimes you shouldn’t plant that mountain ash, birch clump, or crabapple right where you had in mind. But another location on the property could be perfect. If you only have one available site, there are always plenty of great selections able to live long and prosper there.</p>
<p>One of my favorite resources on landscape tree selection is a free booklet published by Cornell University’s Urban Horticulture Institute. It’s written largely by Dr. Nina Bassuk, whose work is universally esteemed by arborists. You can get the download at <a href="http://www.hort.cornell.edu/uhi/outreach/recurbtree/pdfs/~recurbtrees.pdf">http://www.hort.cornell.edu/uhi/outreach/recurbtree/pdfs/~recurbtrees.pdf</a> (No, I’m not at all biased – why do you ask?) Also, Tree Canada has an excellent resource page at <a href="https://treecanada.ca/resources/canadian-urban-forest-compendium/8-species-selection-and-planting/">https://treecanada.ca/resources/canadian-urban-forest-compendium/8-species-selection-and-planting/</a></p>
<p>Given our long winters, it’s good to have trees with off-season aesthetic interest. Here are just a few ideas:</p>
<ul>
<li>Hawthorns are salt-tolerant native trees maturing at around 20’; good for under utility lines. 'Winter King' has copious persistent fruit that look great in winter and provide bird food.</li>
<li>River birch are medium-large trees with attractive and unusual pinkish-white exfoliating bark. 'Heritage' is resistant to many pests and diseases.</li>
<li>Kentucky coffeetrees are tall and drought-tolerant, with few pests or diseases. Their coarse-textured branches produce a striking winter effect.</li>
<li>For spacious sites, bur oak has twisting branches with corky wings. A bur oak silhouette in winter is breathtaking. Especially if it’s real cold. These massive trees tolerate both drought and intermittent flooding, and can live hundreds of years.</li>
</ul>
<p><em>ISA-Certified Arborist Paul Hetzler is a former Cornell Extension educator. He’s looking for new mantras.</em></p>
<p> </p>More about Beech Controltag:cornellforestconnect.ning.com,2022-01-17:6448444:BlogPost:1115312022-01-17T16:18:52.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Beech Gone Wild: Raging Hormones</p>
<p>The American beech (<em>Fagus grandifolia</em>) has been slowly dying out for the last 140 years. As a result, beech saplings have overrun many woodlots, making them less diverse, less vigorous, and less valuable.</p>
<p>That’s right – beech decline has led to a beech proliferation so extreme that in some places they are a barrier to forest regeneration. I’d call this an oxymoron, but don’t want to insult the bovine community. Strategies do exist to…</p>
<p>Beech Gone Wild: Raging Hormones</p>
<p>The American beech (<em>Fagus grandifolia</em>) has been slowly dying out for the last 140 years. As a result, beech saplings have overrun many woodlots, making them less diverse, less vigorous, and less valuable.</p>
<p>That’s right – beech decline has led to a beech proliferation so extreme that in some places they are a barrier to forest regeneration. I’d call this an oxymoron, but don’t want to insult the bovine community. Strategies do exist to address this problem, though.</p>
<p>Long-lived and stately, beech grow throughout eastern North America from Wisconsin and Missouri east to the Atlantic, and from northern Florida all the way to northern Ontario and Quebec. Historically, beech was a keystone species in many long-term stable forest communities. From mice to grouse to black bears, a host of wildlife once relied – and still do to an extent – on beech nuts.</p>
<p>In the late 1800s, a European scale insect arrived in Nova Scotia. Simply called the beech scale (<em>Cryptococcus fagisuga</em>), this soft-bodied pest ranges from 0.5 to 1 mm long, or in non-metric terms, wicked-small to crazy-small. The frail, flightless pest can’t even crawl, except for briefly upon hatching; it passively disperses on wind or birds’ feet. Once on a beech trunk, it inserts a thin stylet into the phloem and takes a wee sip of tree juice, which doesn’t sound too menacing.</p>
<p>We’re living through a nasty demonstration of what microbes a bazillion times (well, at least a quadrillion, but I forget what comes after) smaller than us can do. Similarly, the minute beech scale can slay trees millions of times their size through a scheme of rather permissive family planning.</p>
<p>Beech trees could probably handle throngs of insects each robbing a taste of sap. But every time a scale’s micro-straw jabs through the bark, a native fungus in the genus <em>Nectria</em> comes with it and engages in rotten behaviour. This unhurried decimation is termed beech bark disease.</p>
<p>Beech-scale insects exude white filamentous wax, and large infestations look like fuzz or white mold. Rough, puckered areas of bark indicate <em>Nectria</em> has killed the phloem beneath and is busy turning wood to sponge. Dead patches eventually merge, cutting off water to the crown.</p>
<p>But all that’s beside the point. This is really about why hormone imbalance is a threat to forests.</p>
<p>A beech tree’s post-mortem baby boom is related to how it procreates. Like poplars, beech can spread by root sprouts, clones of the mother tree, in addition to seed production. Overstory beech crank out growth-inhibitor hormones to stifle the mass-emergence of root sprouts. They don’t want competition while they’re in charge.</p>
<p>When a mature beech dies, hormone constraints go, too. With no mother tree keeping things in check, it’s “bring in the clones.” Given that a tree’s root zone is three times its branch length, every sizeable beech that expires creates a broad, dense monoculture of saplings. Curiously, beech scale rarely attacks trees under 8” in diameter, so root-sprout saplings are free from the threat of beech bark disease for some time.</p>
<p>Never mind that they’re the bane of maple producers trying to run tubing, and mess things up for hunters by retaining leaves all winter; beech thickets inhibit forest regeneration. Anything that interferes with the natural regrowth of a diverse woodland will lead to a less productive and less resilient future forest. Competition for water and nutrients is minor compared to the battle for sunlight. A mini-forest of sprouts will one day succumb to beech scale, but not before they shade out everything else.</p>
<p>In terms of mechanical control, it’s a lot more effectual to cut in early summer just after leaf-out is complete. This puts the maximum strain on the organism. By late summer, a season’s worth of photosynthate has been tucked away for next year.</p>
<p>Even in small woodlots, severing countless beech stems at the base is daunting. Chainsaws are a poor option, as working bent-over strains the back and quickly fatigues operators, increasing the chance of mishap (plus in my experience, saw chains are magnets for hidden rocks). A pro-model string trimmer with a circular blade is easier on the back, but there remain issues of fatigue and potential injury.</p>
<p>Canadian Institute of Forestry research concluded that “high stumping” at about 3 feet was as effective as basal cutting. With a two-handled lopper, there’s no bending, and less risk of injury. Cutting stems with a brush head on a small tracked vehicle is likely the best method for large tracts.</p>
<p>Don’t laugh if you haven’t heard of flame-weeders, but they’re used to burn the basal cambium of small trees. With such fire potential, early winter with a veneer of snow may be the only safe window to work. Bark should be heated until well-done, as I’ve seen “undercooked” trees live through flame treatment. Mechanical controls are typically repeated for several years.</p>
<p>Admittedly, chemical control is effective, but organic certification or environmental / health concerns might nix it. Concentrated (25% to 50%) glyphosate is dabbed or painted on beech stumps within 72 hours of being cut. Timing is crucial: cut-stump treatment is far more successful in early fall when woody plants move sugars and nutrients into the roots. When done properly, around 90% of beech saplings are usually killed by one application.</p>
<p>I suggest hiring a professional forester to help with beech-thicket control, especially if chemical use is on the table (figuratively, of course). Readers probably know that Peter Smallidge, Cornell Extension Forester for NY State and curator of this site, has great articles on this blog, as well as YouTube demonstrations. Find links at <a href="https://cornellforestconnect.ning.com/forum/topics/beech-management-1">https://cornellforestconnect.ning.com/forum/topics/beech-management-1</a></p>
<p><em>Paul Hetzler is an ISA Certified Arborist, and a former Cornell Extension Educator.</em></p>Wood Heat: Up In Smoke?tag:cornellforestconnect.ning.com,2021-12-18:6448444:BlogPost:1116272021-12-18T17:20:52.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Where There’s Smoke</p>
<p>An upswing in woodstove use might sound yawn-worthy, but recent findings about the dire health effects of wood smoke might mean the long-term future of wood as a heating fuel is in question.</p>
<p>As someone who grew up with wood heat, I assumed it was hands-down one of the most sustainable, eco-positive fuels for home heating. Like many other widely shared conventions, it turns out the veracity of that assumption depends on a lot of things.</p>
<p>How many…</p>
<p>Where There’s Smoke</p>
<p>An upswing in woodstove use might sound yawn-worthy, but recent findings about the dire health effects of wood smoke might mean the long-term future of wood as a heating fuel is in question.</p>
<p>As someone who grew up with wood heat, I assumed it was hands-down one of the most sustainable, eco-positive fuels for home heating. Like many other widely shared conventions, it turns out the veracity of that assumption depends on a lot of things.</p>
<p>How many people burn wood in a given locale is an obvious factor. The number of homes using wood heat rose sharply in the years following the 1998 ice storm which left residents without power for weeks on end. Also no surprise, the COVID-19 pandemic has accelerated the use of wood heat.</p>
<p>My neighbor, who is a longtime chimney sweep, told me he’s noted an increase in the use of wood heat in the past eighteen months. The much-publicized exodus of urban dwellers to the country has meant additional work for him, and he said “I don’t need any more business right now.”</p>
<p>This frenzy of wood burning is ill-timed, however. As reported in <em>The Guardian</em> on 1 January 2021, health-care professionals now say wood smoke “…may be damaging every organ in the body, with effects including heart and lung disease, diabetes, dementia, reduced intelligence and increased depression. Children and the unborn may suffer the most.”</p>
<p>The referenced article notes that “Dr. Nick Hopkinson, medical director at Asthma UK and British Lung Foundation, said both indoor and outdoor pollution caused by wood burning stoves caused serious health issues, from breathing problems to an increased risk of heart attacks, strokes and lung cancer.” The story also states that “…wood-burners triple the level of harmful particulates inside the home as well as creating dangerous levels of pollution in the surrounding neighbourhood.”</p>
<p>The fact is that these fine particulates, smoke elements less than 2.5 microns in diameter that remain suspended in air almost indefinitely, are the real concern. They are tiny enough to lodge in the alveoli, the deep lung tissue, and accumulate there. This can reduce lung function permanently in adults, and arrest the full development of children’s lungs. Other harmful pollutants in smoke include volatile aromatic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), both of which are known carcinogens.</p>
<p>Again, having grown up around wood smoke and being mostly not dead yet, I could brush off such reports as hyperbole. But I had lived in a remote area with only one neighbor within a mile. Population density matters a lot.</p>
<p>In terms of places where wood-smoke pollution can be significant due to population, let’s look at Montréal. The public health department estimated that on the island of Montréal, wood smoke causes nearly 1,000 premature deaths, over 6,000 childhood bronchitis cases, and at least 40,000 asthma attacks annually. In addition, a city-wide wood-smoke study released in 2000 found that in winter, levels of fine particulates and other dangerous air pollutants were higher in Montréal’s residential neighborhoods than in its urban core. Considering that children are at higher risk of smoke-induced health complications, the grim warnings sound less like exaggerations.</p>
<p>Going back to my friend the chimney sweep, he has a few thoughts on the future of wood burning. Given his profession, he’s not against it, yet he contends “There are greener ways to heat your home than with wood.” First of all, he urges everyone to get a thermal audit of their home. In addition, he’s a big proponent of thermal pumps, which he feels are an underutilized yet readily available technology. He also brought up the issue of forest management, saying that imprudent harvesting is neither sustainable nor “green.”</p>
<p>Today’s catalytic-combustion woodstoves emit little to no smoke when run properly. They also deliver more heat per wood volume burned, so they will save you big on firewood costs. One catch is that burning firewood of less than 20% moisture content is a requisite for the modern breed of stoves to work right. Typically that means at least twelve months of wood being cut, split, stacked and sheltered from rain in a well-ventilated space. I asked my neighbor if he thought the recently arrived ex-urbanites had a decent grasp on woodstove operation. He laughed. “Most haven’t got a clue.”</p>
<p>This is where education comes in. He told me that although cleaning soot and creosote pays the bills, his real passion is educating folks about the importance of burning wood right. Yes, fire is an amazing tool that has been with us since the Stone Age, and back when there were six people on the planet, all that mattered was keeping it lit. Today we have a ton more neighbors, and we just found out that we’ve grossly underestimated the health effects of wood smoke.</p>
<p>It’s imperative to burn clean, burn less, and explore ways to conserve energy and make our homes more efficient. It will keep children healthier, save firefighters from risking their lives at house fires caused by improper wood burning, and save tax dollars. This doesn’t mean entirely giving up on wood-burners – they’re here to stay. As this veteran chimney cleaner told me, “It gives people a sense of empowerment. Plus there’s nothing quite like the warmth from a wood fire.” Amen to that, sir.</p>
<p><em>Paul Hetzler has been an ISA-Certified Arborist since 1996 and is a former Cornell Cooperative Extension Educator.</em></p>
<p> </p>how trunk decay works (and doesn't)tag:cornellforestconnect.ning.com,2021-11-19:6448444:BlogPost:1111292021-11-19T13:47:03.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Lips and Walls: Digging into Tree Decay</p>
<p>When clients call about decay in large older trees, every so often it’s necessary to respond that I’m not interested in hearing any lip from them. I do this respectfully of course.</p>
<p>It’s a frequent misconception that the roll of callus tissue or “lip” that trees produce at the margins of a wound will cause, or at least accelerate, trunk rot by catching and holding a small amount of rainwater. It makes perfect sense to us that if an open…</p>
<p>Lips and Walls: Digging into Tree Decay</p>
<p>When clients call about decay in large older trees, every so often it’s necessary to respond that I’m not interested in hearing any lip from them. I do this respectfully of course.</p>
<p>It’s a frequent misconception that the roll of callus tissue or “lip” that trees produce at the margins of a wound will cause, or at least accelerate, trunk rot by catching and holding a small amount of rainwater. It makes perfect sense to us that if an open tree wound is allowed to stay wet for longer, it will decay faster. We all know that a stack of wood exposed to the elements will turn punky in a few years, whereas if it’s kept in a dry shed it can last indefinitely.</p>
<p>Strange though it may seem, tree decay is not a function of whether or not an open wound is protected from the weather. No matter how fastidiously one covers a large trunk injury, wood at the center of a tree gets more than enough moisture from the surrounding live tissues (cambium and sapwood) for decay organisms to thrive. In fact, letting a wound get soaked by the rain may actually halt the progress of rot, as those agents can’t grow in saturated, anoxic conditions.</p>
<p>Unlike a pile of inert lumber, trees actively defend themselves against decay with protective structures and processes which are analogous in some ways to our immune systems. Since trees don’t always succeed in these endeavors, let’s look at how “treemunity” works and why it sometimes fails.</p>
<p>Thanks in large part to the late Dr. Alex Shigo of the US Forest Service, we know a lot more about the way trees protect themselves than we did before about 1970. When an injury occurs, a tree converts a portion of its stored sugars to make defensive compounds. These chemicals are then deposited in very precise patterns internally around a wound. Shigo was the first to document this response, which he called the compartmentalization of decay in trees, or CODIT.</p>
<p>The four different types of chemical walls are readily visible, though they can only be seen after death (of the tree, I mean) when its wood is sliced open. The first wall cements shut the water-conductive xylem tubes above and below an injury in a roughly horizontal plane. The next is a semicircular arc which follows a portion of an annual ring just inside the wound. The third kind of wall is radial, isolating damage on either side in two planes which converge at the center of the trunk. The fourth and strongest wall is chemically superior new tissues that are laid down after an injury. This includes subsequent years’ growth as well as callus tissue.</p>
<p>I highly recommend a fabulously illustrated booklet that shows how these four biological walls develop. The stunning color plates border on psychedelic, so if you’re not into tree biology, you can still kick back some evening with a relaxing product of your choice and enjoy a trip through the pages. You can find Dr. Shigo’s inspired booklet at <a href="https://www.nrs.fs.fed.us/pubs/misc/ne_aib405.pdf">https://www.nrs.fs.fed.us/pubs/misc/ne_aib405.pdf</a></p>
<p>Wound closure, sometimes called “healing over,” is unrelated to the extent of internal decay that will occur – this depends on how effectively a tree can wall-off infections. Closure is good because the vascular system no longer has to detour around a wound, but it doesn’t protect against fungi if the tree is too weak to chemically protect itself.</p>
<p>The success of walling-off depends a lot on species. Slow-growing hard maple and white oak, for example, typically generate some of the strongest CODIT responses. Poplar and willow, on the other hand, barely manage any walls, figuring (I assume) they can outgrow the decay agents.</p>
<p>Overall tree vitality is another important factor. We know that when we are run-down, we’re a lot more vulnerable to illness. Even a hard maple won’t be able to form strong chemical barriers if it has suffered past root injuries, soil compaction, repeated defoliations or drought stress. By definition, a landscape tree surrounded by grass (its arch-enemy) is stressed compared to a forest-dwelling cousin. Street trees have it worse yet, faced with reflected heat, limited root space, and road salt.</p>
<p>The size of a wound is also critical. Happy, healthy trees can have their defenses overwhelmed by large wounds. We know that many times, trees lose their battle against decay.</p>
<p>In addition to fighting the forces of rot, a tree also uses its internal chemistry set to fight insect pests, making compounds known to scientists as “Bad Tasting Stuff” to repel them (insects, not scientists). But these designer chemicals aren’t perfect – just look at what tent caterpillars and LDD (formerly gypsy) moth caterpillars can do.</p>
<p>It has recently come to light that trees have an early-warning system. Apparently they can signal one another about what type of pest has arrived on the scene, communicating by way of underground root grafts as well as through beneficial symbiotic soil fungi called mycorrhizae. Some biologists think airborne chemicals also carry messages related to pests and diseases.</p>
<p>You can help maximize your tree’s “immune system” by watering during dry spells, mulching out to the branch length or dripline (best not to have grass under your trees!), and by keeping vehicles away from the root zone. In return, your tree will help keep you in optimal health by offering shade, beauty and companionship.</p>
<p><em>ISA-Certified Arborist and former Cornell Cooperative Extension Educator Paul Hetzler tries to stay on the good side of trees.</em></p>HELP PREVENT OAK WILTtag:cornellforestconnect.ning.com,2021-08-10:6448444:BlogPost:1097062021-08-10T01:57:15.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Painting Our Way Out of a Corner</p>
<p>It’s normal to tune out all the Chicken Littles (such as yours truly) who run around squawking about this or that invasive forest pest or disease that pose a threat to trees. I mean, how many times can the sky fall, anyway? But the real danger is when we feel so overwhelmed that we throw up our hands. Thinking we can’t make a difference could result in more harm to forests than the pests themselves.</p>
<p>There’s a pithy fable about a child who…</p>
<p>Painting Our Way Out of a Corner</p>
<p>It’s normal to tune out all the Chicken Littles (such as yours truly) who run around squawking about this or that invasive forest pest or disease that pose a threat to trees. I mean, how many times can the sky fall, anyway? But the real danger is when we feel so overwhelmed that we throw up our hands. Thinking we can’t make a difference could result in more harm to forests than the pests themselves.</p>
<p>There’s a pithy fable about a child who rescues starfish from the beach after storms, and some busybody informs the kid that they can’t save all the starfish. The child responds by hurling another starfish into the sea and quips “yeah but I saved that one.” Right now we have the chance to help save oaks from a devastating new disease, not by tossing them in the ocean, but by adopting some painless and cost-free practices when pruning or harvesting oaks.</p>
<p>Oak wilt (<em>Bretziella fagacearum</em>), a virulent pathogen first identified in 1944 in Wisconsin, has moved into New York State with a vengeance, mainly in the past decade. This disease, which is of unknown origin, will turn a lush, healthy red oak to a crispy critter in just two weeks. Tree pathogens don’t get much nastier than that – I suppose if it also caused oaks to burst into flames, that would be worse.</p>
<p>Oak wilt spreads through root grafts as well as spore transfer. Underground tree-to-tree spread, while an important pathway near active outbreaks, is less important than airborne transmission. This latter route is where we come in.</p>
<p>Healthy red, black, pin, scarlet, and other “red-type” oaks succumb in a matter of weeks, while “white-type” oaks such as bur and swamp-white oaks don’t bite the dust so spectacularly, taking a year or two to die. After a red-type oak is killed, the pathogen makes mycelial spore pads under the bark, causing small bark splits. A spore-laden ooze, reported to smell like Juicy Fruit gum, is secreted, which attracts insects, the most significant of which are sap beetles in the family Nitidulidae.</p>
<p>Nitidulid beetles feed on sugars from the sapwood of newly cut or wounded hardwoods. Normally, not a problem, unless the beetles have recently wallowed in disease spores at an oak-wilt spore pad. Though spore pads develop only on red-type oaks, all oaks can be infected by a spore-covered beetle if it finds a fresh wound during the beetles’ flight season.</p>
<p>So here’s the big news: Paint is your friend.</p>
<p>From April 1 - July 1, the risk of spreading oak wilt is extreme, and from July - September 30 it’s moderate. Any exposed fresh wound on an oak, whether a stump after a tree removal or a pruning wound, puts them at risk. Rule One is never to cut oaks, or allow them to be accidentally wounded, from March through September. OK, now stop laughing – that’s not a rule.</p>
<p>Although it would be ideal not to prune or harvest oaks all spring and summer, it’s impossible. The work-around is to paint each wound or stump immediately after cutting. Spray paint is easiest, but it can be any cheap, leftover exterior product – whatever you have. But use it right away, as nitidulid beetles can find fresh oak sap in under an hour. On pruning wounds, paint the whole thing (Having spent years trying to convince people not to paint wounds, this is hard for me as an arborist). With stumps, only the sapwood needs to be covered.</p>
<p>It would be fair to ask why a stump should be painted. It’s because depending on how many root grafts are interconnected with that stump, spores deposited on a cut stump could infect many nearby oaks through grafts – roots extend three times the branch length. </p>
<p>Painting oak stumps and pruning wounds between March 1 and September 30 must become standard practice in the forestry, utility-clearing, and tree-care industries, But Jane Q. and John Q. Public have a role to play as well. Demand this practice from any arborist you hire, and put it in the contract if you have a woodlot harvested. If there are oaks in your landscape that you prune yourself, follow the same guidelines.</p>
<p>Oak wilt is not hundreds of miles away from us. It’s as close as the first idiot who brings firewood home from visiting his buddy whose dead tree he helped cut up. (History shows that most such idiots are guys; hence the gender exclusion.) Don’t move firewood long distances!! Here is our chance to hold a very important line. Implementing these strategies will vastly reduce the risk of seeing oaks go the way of the American chestnut. Let’s do our part to prove Chicken Little wrong.</p>
<p>If you suspect oak wilt, please report it to your nearest NYS Department of Environmental Conservation office. See: <a href="https://www.dec.ny.gov/docs/lands_forests_pdf/owfactsheet2.pdf">https://www.dec.ny.gov/docs/lands_forests_pdf/owfactsheet2.pdf</a> for more information.</p>
<p><strong>Paul Hetzler, an ISA Certified Arborist and former Cornell Cooperative Extension Educator, is presenting a free program on oak wilt this Thursday, August 12 at 6 PM at the Indian River Lakes Conservancy in Redwood. For details, see</strong> <a href="https://indianriverlakes.org/upcomingevents/"><strong>https://indianriverlakes.org/upcomingevents/</strong></a></p>
<p><em>Paul Hetzler has been an ISA-Certified Arborist since 1996 and is a member of NYS Arborists and the Society of American Foresters.</em></p>Gypsy Mothstag:cornellforestconnect.ning.com,2021-05-17:6448444:BlogPost:1085722021-05-17T23:54:00.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p></p>
<p>Like a B-grade horror film sequel, the aliens have awakened once again. Perhaps we felt a glimmer of hope at the end of the 2020 version when an entire generation of ruthless monsters died off in droves and left us in peace. But remember that closing shot of their disgusting, furry egg-mass blobs cleverly hidden out of sight? Well they’re hatching now.</p>
<p>If you missed last year’s gypsy moth performance, you have a better chance of catching it this season. Unfortunately. Based on…</p>
<p></p>
<p>Like a B-grade horror film sequel, the aliens have awakened once again. Perhaps we felt a glimmer of hope at the end of the 2020 version when an entire generation of ruthless monsters died off in droves and left us in peace. But remember that closing shot of their disgusting, furry egg-mass blobs cleverly hidden out of sight? Well they’re hatching now.</p>
<p>If you missed last year’s gypsy moth performance, you have a better chance of catching it this season. Unfortunately. Based on egg-mass sampling, the New York State Department of Environmental Conservation predicts that areas which saw moderate to severe gypsy moth outbreaks last year can expect heavy damage this year. NYSDEC’s gypsy moth page can be found <a href="https://www.dec.ny.gov/animals/83118.html">here</a>.</p>
<p>Native to Europe, the gypsy moth’s range now extends throughout Africa, Asia, and North America. Its genus, <em>Lymantria,</em> means “destroyer,” an apt designation, and its species name, <em>dispar dispar</em>, reflects the disparate color of males vs. females. It might as well stand for “despair, despair,” since that’s how many of us feel as we watch tree leaves vanish into the maws of gypsy moth caterpillars.</p>
<p>Their introduction in 1868 was especially tragic, as it was deliberate. Étienne Léopold Trouvelot, a French artist, astronomer and so-called scientist, imported gypsy moth egg masses to his Massachusetts home. He thought they could be used to make silk, despite good evidence to the contrary, and without a thought to their potential impact on New World ecosystems. Glass herbariums were safe but pricey, so he raised these fearsome defoliators the woods behind his house. What could possibly go wrong?</p>
<p>Today, gypsy moths are one of the most destructive forest pests in eastern North America, stripping the foliage off at least 300 species of native woody plants. They prefer oaks, but will feed on apple, pine, basswood, spruce, willow, and when population densities are high enough, almost any tree species. In an ironic twist now that EAB is here, gypsy moth caterpillars generally avoid ash. Butternut, walnut and balsam are typically off the menu, too.</p>
<p>Hatchling larvae are black with long hairs, or setae. As the larvae grow, they molt, shedding skins every time they advance to another phase (instar). Later-instar caterpillars develop pairs of raised blue (nearer the head) and dark red (toward the rear) spots along their backs, reaching maturity in early July. After a 14-17-day pupal phase, the adult moths emerge. The mostly-white females can’t fly from where they emerged, and just call out to the boy-moths, which are mottled brown, using pheromone come-on signals. Mated females lay on average around 500 eggs in a “blob” or mass, which they protect with buff-colored hairs taken from their underside.</p>
<p>These oval-shaped egg masses, tan to cream in color and about 0.75 x 1.5 inches (19 x 38 mm), can be found tucked away near whatever hiding spot the female pupated in. Very often laid on tree trunks and notably under flaps of loose bark, egg masses are usually in sheltered spots, but may be just about anywhere. Right now in early May, tiny hatchlings can be found clustered on these masses – it’s a great time to seek and destroy.</p>
<p>Natural predators include blue jays, robins and catbirds, but these have no measurable effect on gypsy moth numbers. The white-footed mouse, the primary reservoir of the three species of <em>Borrelia</em> spirochete bacteria that cause Lyme disease, has redeemed its reputation: it’s the most important vertebrate gypsy moth control, as it loves eating their egg masses. Shrews and other small mammals enjoy hearty breakfasts of gypsy moth eggs, too.</p>
<p>More significant agents are weather, viruses and fungi. As with the tent caterpillar species, prolonged wet, cool weather can lead to hatchling starvation, and a sudden cold snap in late fall or early winter can kill eggs before the embryos inside can winterize their cells. Cool temps also favor infection by fungal pathogens, as explained below.</p>
<p>An endemic soil fungus, nicknamed <em>Entomophaga maimaiga</em> for short, kills gypsy moth caterpillars as their populations rise. But NPV (nucleopolyhedrosis virus) is our MVP when it comes to knocking defoliator numbers down. The catch is that this naturally-occurring virus usually takes two years to precipitate a gypsy moth population crash.</p>
<p>In addition to egg-mass mashing, we can smother eggs that we can’t reach with a shot of dormant-oil spray. This is a very light, highly refined horticultural oil. Some people use aerosol non-stick cooking oil such as Pam, although strictly speaking this might not be legal. (I promise not to tell.)</p>
<p>Applications of <em>Bacillus thuringiensis kurstaki</em>, or Btk to its pals, will protect foliage. Found at any garden center, preparations of Btk contain a natural toxin produced by these bacteria. It is highly specific to caterpillars, and considered safe for other terrestrial and aquatic life. It must be ingested to have an effect. It does wash off, so re-apply after it rains.</p>
<p>Wrapping trunks with a 6” fabric strip, and then smearing it with a sticky compound made for the purpose of trapping insects (Tanglefoot and other brands) will trap larvae, which tend to commute down to the ground at night and back to the treetops in the morning. A “skirt” of burlap tied around trunks will draw caterpillars to take shelter under the fabric, and they can be squished or knocked into soapy water daily. (Caution: the hairs can cause skin rashes and sometimes upper-respiratory irritation.)</p>
<p>Also, never move firewood! Unless it’s from the woodpile to the house – that’s OK. Bringing firewood from home to cottage (or vice-versa) is the best way to spread infestations of all sorts of pests.</p>
<p>Healthy deciduous trees re-foliate after being stripped of leaves, but at great cost to their energy stores. Pines and spruces, though, aren’t endowed with re-foliation powers, and are left with a smattering of green razor stubble with which to photosynthesize; thus gypsy moths can cause such conifer species grave harm. When defoliation occurs in successive years, tree mortality becomes a concern.</p>
<p>Don’t be shy about scouring the back yard in the coming days for egg masses to squish, and it’s probably a good idea to stock up on Btk before the June rush when everyone begins to notice the caterpillars. Let’s hope there’s no remake next year. For more information, see NYSIPM’s gypsy moth resource <a href="https://blogs.cornell.edu/nysipm/2020/07/30/people-are-talking-about-gypsy-moths/">page</a>.</p>
<p><em>Paul Hetzler is an ISA-Certified Arborist and a former Cornell Cooperative Extension Educator.</em></p>Garlic Mustard Managementtag:cornellforestconnect.ning.com,2021-04-16:6448444:BlogPost:1085372021-04-16T12:13:02.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Do Nothing about Invasive Plants</p>
<p>Paul Hetzler, ISA Ceritfied Arborist</p>
<p>Until recently, ignoring problems in hopes they’ll go away hasn’t served me well. However, a decade-long study done by Cornell University researchers has clearly shown that avoidance is the best way to manage garlic mustard (<em>Allaria petiolata</em>), a pernicious exotic plant. Evidently I’ve been doing a great job in the fight against this aggressive and troublesome invader.</p>
<p>Native to most of Europe…</p>
<p>Do Nothing about Invasive Plants</p>
<p>Paul Hetzler, ISA Ceritfied Arborist</p>
<p>Until recently, ignoring problems in hopes they’ll go away hasn’t served me well. However, a decade-long study done by Cornell University researchers has clearly shown that avoidance is the best way to manage garlic mustard (<em>Allaria petiolata</em>), a pernicious exotic plant. Evidently I’ve been doing a great job in the fight against this aggressive and troublesome invader.</p>
<p>Native to most of Europe and parts of western Asia and northwestern Africa, garlic mustard is in the cabbage and broccoli family (<em>Brassicaceae</em>), and indeed was imported to North America as a culinary herb in the early 1800s. It’s not entirely evil, as it has the spicy tang of mustard with a hint of garlic, and can be used as a base for pesto and sauces, and to flavor salads, soups and other dishes. Unfortunately, eating it has not worked well as a control strategy.</p>
<p>Garlic mustard is a biennial that begins as an inconspicuous first-year plant (rosette). At a glance, its rosettes look similar to wild violets, having triangular, somewhat heart-shaped leaves that have coarsely toothed margins and wrinkled leaf surfaces. In the second year it sends up a tall flower spike, the four-petal white flowers developing into slender pods (siliques) bursting with tiny round seeds. This is one of garlic mustard’s unpleasant features, as it loads the soil with seeds that remain viable for ten or more years.</p>
<p>Like most invasive plants, garlic mustard is not browsed by herbivores (if you don’t count vegetarian humans), and has no effective insect pests or diseases to keep it in check. As mentioned, it gets high marks for reproduction, and can form thick monocultures in forest environments. Its roots exude compounds that alter the soil chemistry to favor its survival at the expense of other species. Known as allelopathy, this mechanism also harms mycorrhizae, symbiotic root fungi which contribute greatly to tree health. When dense armies of these plants compete for water, nutrients and sunlight, natural forest regeneration is curtailed and native ground cover is stressed.</p>
<p>Sounds like we should gather a posse and rise up against this intruder; pitchforks, torches, and pikes at the ready. Well, yes and no. If garlic mustard has just appeared at a location in the past one or two years and their numbers are low, yes – yanking them out by the roots is the thing to do.</p>
<p>But according to Dr. Berndt Blossey, a Cornell University conservation biologist who specializes in invasive plants, pulling up large swaths of garlic mustard is not only futile, it is worse than leaving it alone. It bears echoing: When well-intentioned people rip out this stuff, it actually prolongs the infestation period because the plant self-limits (more on that below) if undisturbed. Also, these mass garlic mustard-ectomy events do more damage to the ecosystem than the target species itself does.</p>
<p>There are cases where research seems pointless because cause and effect are so obvious: maple sap flows up from the roots during the day; goldenrod causes allergy symptoms; and garlic mustard wipes out native wildflowers and adversely affects salamanders. These assumptions make sense, given the “evidence,” but upon close examination, all of the above statements are false.</p>
<p>Dr. Blossey has long contended that deer abundance and non-native earthworms are the drivers of garlic mustard infestation. Garlic mustard only establishes after earthworms have invaded a site for some years, he says, and although how deer spread earthworms is not yet known, they apparently do, as exclusion plots show. I first heard Berndt’s idea that well-established garlic mustard should be left alone in 2014 at a talk he gave at Cornell. I was surprised, and admittedly rather skeptical. But he and his team have now done enough controlled trials and amassed enough evidence to back up his assertions.</p>
<p>It turns out that while garlic mustard competes with native species, it does not displace them where deer are excluded or drastically reduced in number. And it is earthworms, not our maligned invasive plant, which make a neighborhood less attractive to salamanders. Furthermore, garlic mustard dwindles in biomass, plant vigor, and site prevalence over time. Within ten to 12 years it becomes scarce as a species, the remaining plants greatly stunted.</p>
<p>Side-by-side controlled trials showed that where garlic mustard is “managed,” the plants are considerably larger and cover a higher percentage of a site (at times by an order of magnitude) than the sections where nothing has been done. Not only that, but biomass on the managed sites tended to be roughly stable over the ten-year time frame studied, whereas it declined year after year in the unmanaged plots.</p>
<p>Pulling garlic mustard where it is abundant prolongs its run. It also robs a great deal of nitrogen, macro- and micronutrients, and organic matter from the ecosystem. Mass-removal also results in the site being trampled, and runs the risk that soil and native plants might be inadvertently removed.</p>
<p>A much better use of our time and energy, Dr. Blossey advises, is to scout sites that aren’t known to have garlic mustard yet, and also to kill as many deer as possible. Especially the latter.</p>
<p>An interesting side note is that if deer were managed to 5-7 per square mile, not only would it drastically reduce the rate of garlic mustard spread, Lyme disease would cease to be a human-health threat (this from Dr. Paul Curtis, the NY State Extension Wildlife Specialist at Cornell University). I say amen to that!</p>
<p>Professor Blossey’s February 26, 2021 talk “When Doing Nothing is the Best Invasive Plant Management Tool” can be found at <a href="https://www.youtube.com/watch?v=vRQal0Hq5nM">https://www.youtube.com/watch?v=vRQal0Hq5nM</a></p>
<p><em>A former Cornell Cooperative Extension Educator, Paul Hetzler is often in a recliner, helping to fight garlic mustard.</em></p>Tips for Winter Tree IDtag:cornellforestconnect.ning.com,2021-03-09:6448444:BlogPost:1085022021-03-09T22:57:26.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Tree Buds: Honest Friends</p>
<p>How to distinguish one leaf-bereft hardwood from another in winter is more of a challenge than summer tree ID, but there are practical reasons – and a few offbeat incentives – to tell one species from another in the dormant season. Hikers and skiers can benefit from such a skill, and in survival situations, hydration and warmth may depend on it. And if you’re among those who adore wintertime camping, you can have more fun when you know common woody…</p>
<p>Tree Buds: Honest Friends</p>
<p>How to distinguish one leaf-bereft hardwood from another in winter is more of a challenge than summer tree ID, but there are practical reasons – and a few offbeat incentives – to tell one species from another in the dormant season. Hikers and skiers can benefit from such a skill, and in survival situations, hydration and warmth may depend on it. And if you’re among those who adore wintertime camping, you can have more fun when you know common woody species.</p>
<p>In late winter/ early spring, a pathogen-free beverage flows from sugar, silver, and red maples when temperatures rise above freezing in the day. A bit later in the spring yet prior to leaf-out, our native white (paper), yellow, black, grey, and river birches yield copious, healthful sap as well. The same can be said for wild grape stems, although it’s crucial that one can recognize other vines out there like Virginia creeper and poison ivy.</p>
<p>Being able to tell native shrub dogwood and <em>Viburnum</em> from invasive honeysuckle, <em>Euonymus</em>, and buckthorn may score you some tasty dried berries, and save you from the nasty effects of consuming the wrong ones. If you need fuel wood in a hurry, basswood won’t help, but ash, which has similar bark, definitely will. Black and pin cherry also burn respectably when green.</p>
<p>Foliage is front and center when you crack open a typical field guide. Without such a luxury, we have to look more closely. Bark comes to mind, and while sometimes helpful, it’s not always reliable: bark characteristics change as trees age. Not all hickories have shaggy bark, and the majority of birch species aren’t white-barked. Cherry and ironwood have lenticels on young wood only. Even the characteristic diamond-shaped furrows of ash bark may look different in some conditions.</p>
<p>A better diagnostic tool is arrangement: whether or not twigs grow opposite one another on the branch. Most trees have alternate twig growth, so we’ll focus on opposites: maple, ash and dogwood, or “MAD.” Shrubs and small trees in the family <em>Caprifolaceae</em>, such as viburnums, are opposite, too. The prompt “MAD Cap” may help keep track of who’s opposed and who’s in favor.</p>
<p>All our native dogwoods are shrubs, so maple and ash are the sole members of the opposite-tree club. You’d think that would simplify things, but twigs on any given ash or maple branch are frequently missing some (or at times many) “partner twigs” which are supposed to be opposite them. Wind, ice, pathogens, and other things are apt do that, so don’t trust branch arrangement entirely.</p>
<p>Fortunately for us, buds, like Vulcans, cannot lie. Look closely at a twig to see if the buds are opposite or alternate. Bud size, shape and placement will give further clues. Beech have long, lance-like buds, while those of balsam-poplars are sticky and aromatic. Red and silver maples have puffy, reddish buds. Sugar maple buds are brown and conical, like a sugar cone. Oaks have clusters of buds at the end of each twig. Black locust buds are “submerged” under the bark.</p>
<p>Location gives us some clue about tree ID, too. Riparian zones and other low-lying wooded habitats which are seasonally flooded are not likely to produce healthy sugar maple, white ash, red oak and white pine. On the other hand, red & silver maple, green & black ash, bur oak, white cedar, eastern hemlock, and elm will thrive in those types of places. Invasive and non-regional species like buckthorn, Norway maple and boxelder may show up on sites with a history of disturbance.</p>
<p>Shade-tolerance is of trifling use, as “intolerant” species can hang on a long while as they are shaded out by competitors. Size helps, but in one direction: If faced with a specimen of unusual girth or height, it rules out short-maturing species like American hornbeam (musclewood, ironwood) and hawthorn.</p>
<p>Even the health profile of a species can be an aid. The presence of black-knot lesions indicates a cherry tree, for instance. A towering hardwood with a crop of dark “tennis balls” throughout its canopy is a hickory that is infested with <em>Phomopsis</em> gall disease. A deep, slanting scar on the lower trunk of a hardwood is likely the calling-card of a sugar-maple borer.</p>
<p>Smell is an honest indicator, but it only works for a few species. Yellow & black birch twigs smell and taste like wintergreen. Peel a cherry twig and you’ll get a whiff of bitter (cyanic) almond. Most features of red and silver maple twigs are very similar, but those of silver maple smell rank when broken.</p>
<p>Inside each bud is an embryonic leaf (and/or flower). To protect their tender charges, most tree buds have overlapping scales that open in spring. Basswood buds have two or three scales, which vary greatly in size. Sugar maple buds have many, uniform scales. Butternut and hickory buds have no scales, but depend on a bit of fuzz to guard leaf embryos. All in all, the best winter tree ID tools are buds. It would be a sad world if we couldn’t count on our buds to tell the truth.</p>
<p>For more details on winter tree ID, the booklet <em>Winter Tree Finder</em> is nice, and Cornell’s book <em>Know Your Trees</em> is a free download: (<a href="http://www.uvstorm.org/Downloads/Know_Your_Trees_Booklet.pdf">http://www.uvstorm.org/Downloads/Know_Your_Trees_Booklet.pdf</a>).</p>
<p><em>An ISA-Certified Arborist since 1996, <strong>Paul Hetzler</strong> wanted to be a bear when he grew up, but failed the audition. Having gotten over some of his self-pity concerning that unfortunate event, he now writes about</em><em> nature .</em></p>
<p><strong> </strong></p>Sapsucker Damage Indicates Stressed Treestag:cornellforestconnect.ning.com,2021-02-05:6448444:BlogPost:966012021-02-05T16:10:24.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Sapsuckers and Other Insults</p>
<p>Icebreaker exercises are apparently meant to help awkward group events like staff development days feel even less comfortable. I recall a workplace training where we had to inform the group what animal best represented our personality. I was going to say “squirrel” but got distracted by something out the window, and forgot. In retrospect I should have chosen the yellow-bellied sapsucker (<em>Sphyrapicus varius</em>), since I spent much of that same event…</p>
<p>Sapsuckers and Other Insults</p>
<p>Icebreaker exercises are apparently meant to help awkward group events like staff development days feel even less comfortable. I recall a workplace training where we had to inform the group what animal best represented our personality. I was going to say “squirrel” but got distracted by something out the window, and forgot. In retrospect I should have chosen the yellow-bellied sapsucker (<em>Sphyrapicus varius</em>), since I spent much of that same event straightening business cards and brochures at the conference center. This should make sense in a moment.</p>
<p>Some may raise an eyebrow when they learn that “yellow-bellied sapsucker” is not just an epithet hurled by children across school playgrounds. Indeed it is a woodpecker whose nesting grounds encompass parts of the Great Lakes and New England states, as well as a broad swath of southern Canada. The real surprise is that this creature displays a behavior I would call compulsive.</p>
<p>To be clear, Obsessive-Compulsive Disorder is a challenge for some folks, myself included, so I’m not equating it to the sapsucker’s habits. But when I see the way this bird pecks perfectly straight rows of uniform-sized, evenly spaced shallow holes called sap wells, it reminds me a lot of squaring-off stacks of stationery. Unfortunately, this bird’s obsession sometimes injures or kills trees.</p>
<p>For all the harm it can cause, the yellow-bellied sapsucker is rather small, weighing a mere two ounces. On average it measures about eight inches long, with a wingspan around fourteen inches. It resembles two of our resident native woodpeckers, the downy and hairy, and is a bit larger than the downy, and a tad smaller than the hairy.</p>
<p>Ironically, the yellow-belly is only yellow – and a very pale hue at that – at the center of its abdomen; otherwise its front is mottled (or barred) dark brown and white. It sports a black bib, and has a white stripe down its side, with black above. The male has a red head, and the female generally has at least a red crown.</p>
<p>Sapsuckers feed on many trees: pine, hemlock, maple, and poplar are all on their menu, but they’re especially fond of thin-barked species like birch, mountain-ash and alder. Apple trees also seem quite attractive to them.</p>
<p>Although this bird’s existence may not hinge on having a laser-straight, regimented drilling pattern, sapsuckers don’t make sap wells for fun. The name suggests they have a means of vacuuming out tree sap but really, sapsuckers return to feed on sugar-rich dried (or concentrated) sap which collects in the wells it made earlier. In addition, they snap up insects which are attracted to the fresh wounds. Fruits and nuts round out their diet.</p>
<p>Much of the time, sapsuckers aren’t a problem for trees, as they frequently shop around, pecking a short line or two into one, maybe hammering out a paragraph on another trunk or branch. But occasionally the sapsucker will finish a row around the entire circumference of a particular tree, and then drop down a fraction of an inch (truthfully I don’t know what units they use) to begin the next, and on and on.</p>
<p>This ring-around-the-rosy performance chips out most of the cambium layer in that particular row of sap wells, disrupting the vascular system. It’s akin to girdling perhaps 70 or 80 percent of the trunk in that narrow band. Obviously this stresses the tree, and may eventually kill it. Why sapsuckers peck mercilessly on certain trees yet barely touch others of the same kind is not fully known, but I’ve noticed that very often it is a tree already struggling with stress – which includes any tree surrounded by lawn – that gets the bulk of their attention.</p>
<p>My current (untested) hypothesis has to do with the way trees protect themselves from things intent on eating them. A vigorous, vital tree is able to produce noxious compounds at feeding sites in an effort to repel insects, and presumably anything else dining upon it. A tree in a weakened state, however, cannot mount such a defense and is thus “tastier.” We know that in general, insect pests go for stressed and dying trees first. I’m going out on a limb to suggest this is why sapsuckers peck the life out of a landscape tree while ignoring the same species in a nearby wooded setting.</p>
<p>Sadly, the yellow-bellied sapsucker is considered a species of “high climate vulnerability.” The Audubon Society projects that if current warming trends continue, it could lose up to 88% of its current range. The breadth of its nesting habitat will shrink considerably in the south, without being able to expand nearly as much to the north. So let’s be nice to sapsuckers even if they do cause a problem for one of your trees. If that’s the case, wrap the section of trunk under “attack” with burlap, or aluminum window screen. And then make sure it’s getting enough water, and that nobody drives on, or adds soil to, its root zone (twice the branch length). A little bird is telling you the poor tree is stressed-out.</p>
<p><em>Paul Hetzler is an ISA-Certified Arborist and a member of the Canadian Institute of Forestry,and the Society of American Foresters. His OCD issue is under control, but he’s still working on his Attention-Defic</em></p>New Wood Markets for Novel Forest Productstag:cornellforestconnect.ning.com,2021-01-09:6448444:BlogPost:838862021-01-09T17:23:34.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Wooden You Know</p>
<p>As a card-carrying, registered tree hugger, I have long touted the benefits of trees such as carbon storage, energy savings and improved mental health. And beyond the familiar tree-related blessings such as maple syrup, lumber and firewood, I’ve written about some obscure things like birch-based candy that fights tooth decay, and health-promoting chaga tea derived from a birch fungus. Then there’s basswood bark for fiber, elm bark for baskets, and pine bark for lunch.…</p>
<p>Wooden You Know</p>
<p>As a card-carrying, registered tree hugger, I have long touted the benefits of trees such as carbon storage, energy savings and improved mental health. And beyond the familiar tree-related blessings such as maple syrup, lumber and firewood, I’ve written about some obscure things like birch-based candy that fights tooth decay, and health-promoting chaga tea derived from a birch fungus. Then there’s basswood bark for fiber, elm bark for baskets, and pine bark for lunch. That stuff is all pretty straightforward.</p>
<p>More highly processed wood products, though, are a mystery to me. Even a fairly mundane example like how a pile of dirty logs becomes a decidedly coveted treasure – I’m speaking of toilet paper, of course – seems like rocket science. But recent developments are truly mind-blowing. Without a doubt, tree-derived stuff has risen to a whole new level: the Japanese will soon rocket a wooden satellite into space. </p>
<p>A joint venture between Kyoto University and Japanese logging company Sumitomo Forestry aims to have the world's first wooden satellites orbiting the Earth by 2023. Really. There are an estimated 6,000 satellites now orbiting the Earth, and most of them are non-functional. Apparently, each time a dead satellite re-enters our atmosphere, it produces alumina particles as it burns up, and these micro-bits remain in the stratosphere for years, eating away at the protective ozone layer. Of course, when wood burns it does not produce alumina. Toasted marshmallows, perhaps, but not any dangerous pollution. Plus, if one of these satellites should break up in space, wood chips are way less dangerous to the International Space Station than the myriad nuts, bolts and metal shards floating around up there.</p>
<p>The engineers at Kyoto University aren’t using plywood or oriented-strand chip board, obviously. Researchers from the University of Maryland, the National Institute of Standards and Technology, and other institutions have found various ways to make wood super-strong and amazingly light and thin.</p>
<p>The University of Maryland’s “super wood,” as they call it, is equal to steel in strength, yet is lighter than aluminum. Dr. Liangbing Hu, leader of the UM research team, says their low-cost innovation will rival steel and titanium alloys in construction uses, and is much cheaper. Dr. Hu expects it to be used in cars and planes in the future (which makes sense, since using it in the past would be tricky).</p>
<p>Scientists at the National Institute of Standards and Technology have combined wood fiber with, of all things, a marine worm to create a product which is comparable to super wood, but is more flexible. Similar work is being done in many other countries, including France and Sweden, where engineers have focused on transparent wood for shatter-proof windows.</p>
<p>The recent news (see the BBC’s December 2020 report at <a href="https://www.bbc.com/news/business-55463366">https://www.bbc.com/news/business-55463366</a>) about Japanese engineers branching out into wood satellites is pretty amazing, but wood has been moving into unexpected areas for some time now. A very cool example is San Francisco-based Allbird, which since 2014 has been making soft, comfortable wood-fiber running shoes. Made from sustainably grown eucalyptus trees, the sneakers are said to be unusually light, cool and comfortable, especially good for hot climates. </p>
<p>But that’s a pedestrian use compared to what French tire maker Michelin has been doing since 2018. It’s hard to believe that a giant manufacturer like that would take a page from Fred Flintstone. While Fred’s tires were puncture-proof, Michelin’s wood-based tires will look and perform like conventional ones, which on average are 80% petroleum-derived. Michelin engineers have found a way to produce elastomers – which are stretchy compounds, as you might have guessed – from paper-mill waste. These tires are expected to be rolled out within the next two years. Wood-based pneumatic tires can still be pierced by a nail, but are way more comfortable than solid logs. I only hope that companies that produce braking systems aren’t inspired by the Flintstones as well.</p>
<p>And finally, a research team at the University of Delaware has developed a way to make adhesive polymers from tree lignin. By volume, the vast majority of a tree is cellulose. Trees produce lignin for strength on an as-needed basis because it takes a lot of energy to make; on a windy site a tree will produce more, and the same tree in a protected location will produce less. It’s analogous to a normal parking garage, which needs some reinforcing steel in the cement. If that garage is intended for tanks and trucks, a lot more steel had better go in the ‘crete.</p>
<p>Anyway, the University of Delaware group, led by professor of Materials Science and Engineering Dr. Thomas Epps, has created a low-cost adhesive from these lignin polymers. They reportedly made a transparent tape that they say performs as well as commercial Scotch tape. Dr. Epps is now experimenting with a wide variety of tree species to see if the respective lignins, which differ slightly from one kind of tree to another, could have unique applications.</p>
<p>Considering the miracles that trees are, think about planting a few this spring. You never know – you might be growing an actual cure for the common cold.</p>
<p><em>Paul Hetzler has been an ISA-certified arborist since 1996. He claims not to have made any of this up.</em></p>
<p> </p>
<p> </p>
<p> </p>New Wood Markets for Novel Forest Productstag:cornellforestconnect.ning.com,2021-01-09:6448444:BlogPost:838882021-01-09T17:23:23.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Wooden You Know</p>
<p>As a card-carrying, registered tree hugger, I have long touted the benefits of trees such as carbon storage, energy savings and improved mental health. And beyond the familiar tree-related blessings such as maple syrup, lumber and firewood, I’ve written about some obscure things like birch-based candy that fights tooth decay, and health-promoting chaga tea derived from a birch fungus. Then there’s basswood bark for fiber, elm bark for baskets, and pine bark for lunch.…</p>
<p>Wooden You Know</p>
<p>As a card-carrying, registered tree hugger, I have long touted the benefits of trees such as carbon storage, energy savings and improved mental health. And beyond the familiar tree-related blessings such as maple syrup, lumber and firewood, I’ve written about some obscure things like birch-based candy that fights tooth decay, and health-promoting chaga tea derived from a birch fungus. Then there’s basswood bark for fiber, elm bark for baskets, and pine bark for lunch. That stuff is all pretty straightforward.</p>
<p>More highly processed wood products, though, are a mystery to me. Even a fairly mundane example like how a pile of dirty logs becomes a decidedly coveted treasure – I’m speaking of toilet paper, of course – seems like rocket science. But recent developments are truly mind-blowing. Without a doubt, tree-derived stuff has risen to a whole new level: the Japanese will soon rocket a wooden satellite into space. </p>
<p>A joint venture between Kyoto University and Japanese logging company Sumitomo Forestry aims to have the world's first wooden satellites orbiting the Earth by 2023. Really. There are an estimated 6,000 satellites now orbiting the Earth, and most of them are non-functional. Apparently, each time a dead satellite re-enters our atmosphere, it produces alumina particles as it burns up, and these micro-bits remain in the stratosphere for years, eating away at the protective ozone layer. Of course, when wood burns it does not produce alumina. Toasted marshmallows, perhaps, but not any dangerous pollution. Plus, if one of these satellites should break up in space, wood chips are way less dangerous to the International Space Station than the myriad nuts, bolts and metal shards floating around up there.</p>
<p>The engineers at Kyoto University aren’t using plywood or oriented-strand chip board, obviously. Researchers from the University of Maryland, the National Institute of Standards and Technology, and other institutions have found various ways to make wood super-strong and amazingly light and thin.</p>
<p>The University of Maryland’s “super wood,” as they call it, is equal to steel in strength, yet is lighter than aluminum. Dr. Liangbing Hu, leader of the UM research team, says their low-cost innovation will rival steel and titanium alloys in construction uses, and is much cheaper. Dr. Hu expects it to be used in cars and planes in the future (which makes sense, since using it in the past would be tricky).</p>
<p>Scientists at the National Institute of Standards and Technology have combined wood fiber with, of all things, a marine worm to create a product which is comparable to super wood, but is more flexible. Similar work is being done in many other countries, including France and Sweden, where engineers have focused on transparent wood for shatter-proof windows.</p>
<p>The recent news (see the BBC’s December 2020 report at <a href="https://www.bbc.com/news/business-55463366">https://www.bbc.com/news/business-55463366</a>) about Japanese engineers branching out into wood satellites is pretty amazing, but wood has been moving into unexpected areas for some time now. A very cool example is San Francisco-based Allbird, which since 2014 has been making soft, comfortable wood-fiber running shoes. Made from sustainably grown eucalyptus trees, the sneakers are said to be unusually light, cool and comfortable, especially good for hot climates. </p>
<p>But that’s a pedestrian use compared to what French tire maker Michelin has been doing since 2018. It’s hard to believe that a giant manufacturer like that would take a page from Fred Flintstone. While Fred’s tires were puncture-proof, Michelin’s wood-based tires will look and perform like conventional ones, which on average are 80% petroleum-derived. Michelin engineers have found a way to produce elastomers – which are stretchy compounds, as you might have guessed – from paper-mill waste. These tires are expected to be rolled out within the next two years. Wood-based pneumatic tires can still be pierced by a nail, but are way more comfortable than solid logs. I only hope that companies that produce braking systems aren’t inspired by the Flintstones as well.</p>
<p>And finally, a research team at the University of Delaware has developed a way to make adhesive polymers from tree lignin. By volume, the vast majority of a tree is cellulose. Trees produce lignin for strength on an as-needed basis because it takes a lot of energy to make; on a windy site a tree will produce more, and the same tree in a protected location will produce less. It’s analogous to a normal parking garage, which needs some reinforcing steel in the cement. If that garage is intended for tanks and trucks, a lot more steel had better go in the ‘crete.</p>
<p>Anyway, the University of Delaware group, led by professor of Materials Science and Engineering Dr. Thomas Epps, has created a low-cost adhesive from these lignin polymers. They reportedly made a transparent tape that they say performs as well as commercial Scotch tape. Dr. Epps is now experimenting with a wide variety of tree species to see if the respective lignins, which differ slightly from one kind of tree to another, could have unique applications.</p>
<p>Considering the miracles that trees are, think about planting a few this spring. You never know – you might be growing an actual cure for the common cold.</p>
<p><em>Paul Hetzler has been an ISA-certified arborist since 1996. He claims not to have made any of this up.</em></p>
<p> </p>
<p> </p>
<p> </p>Promoting Natural Christmas Treestag:cornellforestconnect.ning.com,2020-12-07:6448444:BlogPost:690542020-12-07T19:04:17.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Pining for the Good Old Days</p>
<p>Children around the globe will be disappointed on Christmas if the World Health Organization doesn’t exempt Santa from COVID-19 restrictions. But I’m sure they will. Due to the pandemic, many authorities advise that we celebrate in our respective households this year; no visitors. Yikes! Looks like we’ll have to rely on past memories for the holidays in 2020, which is bad news for those of us who can’t keep track of our car keys for two…</p>
<p>Pining for the Good Old Days</p>
<p>Children around the globe will be disappointed on Christmas if the World Health Organization doesn’t exempt Santa from COVID-19 restrictions. But I’m sure they will. Due to the pandemic, many authorities advise that we celebrate in our respective households this year; no visitors. Yikes! Looks like we’ll have to rely on past memories for the holidays in 2020, which is bad news for those of us who can’t keep track of our car keys for two minutes.</p>
<p>Fortunately, the most enduring memories are those associated with smell. For Santa, a whiff of reindeer dung probably brings the spirit of the season into focus, but the winter holidays have plenty of sweeter scents – maybe a fresh-baked pie, or a roast turkey – to remind us of Christmases past. For me, though, nothing evokes the holiday spirit like the smell of fresh-cut pine, spruce or fir. Those fragrant evergreen wreaths, trees and garlands help us remember.</p>
<p>Though most American households which observe Christmas now use artificial trees, last time I checked, around eleven million families still bring home a real tree. Every conifer species has a unique combination of terpenols and esters that account for its “piney woods” perfume. A natural Christmas tree is, among other things, a giant holiday potpourri. No chemistry lab can make a plastic-and-wire tree smell like a fresh evergreen.</p>
<p>Evergreen trees and boughs were used by many ancient peoples to symbolize eternal life. Martin Luther apparently helped kindle (so to speak) the custom of indoor home Christmas trees in sixteenth-century Germany by bringing an evergreen into his house and decorating it with candles. For centuries, Christmas trees were brought inside on December 24<sup>th</sup> and were not removed until after the Christian feast of Epiphany on January 6<sup>th</sup>.</p>
<p>In terms of regional favorites, Douglas, balsam, and Fraser firs are popular aromatic evergreens with superior needle retention. Pines also hang onto their needles well. Scots (not Scotch; that’s for Santa) pine outsells our native white pine, possibly because the sturdy Scots can bear lots of decorations without its branches drooping. But white pine has a deeper fragrance, so take your pick. Not only do spruces have stout branches, they have a strongly pyramidal shape, and their short needles make them easy to decorate.</p>
<p>The annual pilgrimage to choose a tree is for many families a cherished holiday tradition, a time to bond. I look back fondly on our customary thermos of hot chocolate, the ritual of the kids losing at least one mitten each, and the time-honored squabble – I mean discussion – regarding which tree is best. Good smells and good memories.</p>
<p>One of the pandemic’s side effects seems to be more interest in natural Christmas trees, and I’m told that in some places they can be in short supply. Nonetheless, I encourage everyone to consider a natural tree. They are a renewable resource, and boost the regional economy as well. Tree farmers as well as local vendors are happy to help you select the best kind of tree for your family’s preferences. </p>
<p>For maximum fragrance and needle retention, cut a one- to two-inch “cookie” from the base of the trunk before placing your tree in the stand, and fill the reservoir every two days. Research shows that products claiming to extend needle life really don’t work, so save your money. LED tree lights don’t dry out the needles like the old style did, and are easier on your electric bill too. Find more information on how to select and care for your Christmas tree <a href="https://ctfany.org/finding-the-perfect-new-york-grown-christmas-tree-about-new-york-grown-christmas-trees/">here</a>.</p>
<p>Even if you can’t get together as in years past, I hope your family, friends, and evergreens are all well-hydrated, sweet-scented and a source of good memories this holiday season.</p>Woodpeckers Are Beneficialtag:cornellforestconnect.ning.com,2020-12-07:6448444:BlogPost:689622020-12-07T18:58:49.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Messengers, Not Miscreants</p>
<p>If you get bad news about one of your trees, kindly don’t blame the messenger. Even if – especially if – they vandalize that very tree. It could save a lot of trouble, and possibly your life, to heed their memo.</p>
<p>Although it’s captivating to watch a big prehistoric-looking woodpecker chisel away at a rotten snag in the forest, the same performance loses its charm when it jack-hammers a hole in your perfectly good tree. The thing is, no matter how…</p>
<p>Messengers, Not Miscreants</p>
<p>If you get bad news about one of your trees, kindly don’t blame the messenger. Even if – especially if – they vandalize that very tree. It could save a lot of trouble, and possibly your life, to heed their memo.</p>
<p>Although it’s captivating to watch a big prehistoric-looking woodpecker chisel away at a rotten snag in the forest, the same performance loses its charm when it jack-hammers a hole in your perfectly good tree. The thing is, no matter how healthy that tree may appear, it is definitely not sound, and may in fact be dangerous. Your “vandal” is alerting you to this truth by installing windows in the tree trunk.</p>
<p>Native to the eastern United States, southeastern Canada and a belt of Canadian boreal forest stretching to the Pacific coast, the pileated woodpecker (<em>Dryocopus pileatus</em>) is easy to recognize. Its prominent red crest is an attention-getter, but its size sets it apart as well. Assuming the ivory-billed woodpecker is extinct, our pileated is the largest in North America, at 40-49 cm long, with a 66-75 cm wingspan. Its body is mostly black, with a strip of white down the throat. Males and females are both red-crested, but the male has an additional red stripe on the sides of its head. Patches of white are also visible as it flies in its distinctive undulating pattern.</p>
<p>Pileated woodpeckers excavate large cavities in dead trees in which to nest – so large that the tree sometimes collapses at the nest site. They also “mine” dead trees for larvae and pupae of wood-boring beetles. But these birds have a special appetite for carpenter ants living in the decayed heartwood of live trees, which is what sometimes irks when it seems that they’re attacking a healthy tree in our woodlot, sugar bush, or backyard. As unsettling as it is to see wood chips raining down from your tree, that is the least of its problems.</p>
<p>It’s tough work for woodpeckers to chop holes in wood using only their lips, so there’s always a compelling reason, such as a tasty carpenter-ant core ensconced within that hard wooden shell. It’s sort of the bird equivalent of a lollipop with a chewy center. Once we realize these professional hackers only break into a live tree if its trunk is packed with ants, it’s logical to think we should kill those critters. The trouble is, that won’t help – ants aren’t the issue either.</p>
<p>In spite of their name, carpenter ants are unable to saw, router, drill, or otherwise excavate solid wood. Turns out these guys only have the chops for damp, rotted wood. They’re so named (I’m pretty sure) because when they appear at home it means you need a carpenter, as opposed to an exterminator, to replace that crumbling sill plate, joist, or other hidden piece of decayed lumber. In houses, rot may be due to faulty window flashing or leaking roofs. Heartwood rot in trees, however, begins with an injury.</p>
<p>Ice storms, lightning strikes, porcupines and other natural injuries are unavoidable, but we cause loads of unnecessary harm. Root damage is a frequent but lesser-known conduit for decay to enter, which is why it’s essential that land managers keep heavy equipment out of the woods in wet conditions. Flush-cut pruning is another type of careless and avoidable injury that can lead to internal decay.</p>
<p>As Peter Smallidge and others have written over the years, trees wall-off (compartmentalize) wounds, making barriers to exclude decay organisms. A fascinating and superbly illustrated USFS bulletin by Dr. Alex Shigo, who extensively studied this “treemunity” process, can be found at: <a href="https://www.nrs.fs.fed.us/pubs/misc/ne_aib405.pdf">https://www.nrs.fs.fed.us/pubs/misc/ne_aib405.pdf</a></p>
<p>Whether or not a tree successfully compartmentalizes decay after an injury depends on its species and vitality, as well as the wound size. Bur oak, sugar maple, and honeylocust are among the species which compartmentalize robustly, while poplar, birch, and willow appear to have skipped the class on how it’s done. Obviously, poor soil, drought, defoliation and root damage curb a tree’s ability to self-protect. But even the defenses of a top-notch (so to speak) tree can be overwhelmed by a large wound.</p>
<p>When a tree’s defensive walls are breached, heart rot often ensues. It’s a slight misnomer, as trees without heartwood (birch, beech, basswood) get it too. Also, depending on the fungal agent, sapwood can sometimes be fair game. In general terms, heart rot affects the non-living center section of trees, while the outer layers of water-conductive sapwood are exempt (if a tree is subject to a further large injury, sapwood can be jeopardized as well).</p>
<p>Broadly speaking there are two kinds of heart rot, white and brown. Brown rot, which decays cellulose only, is sometimes called dry-rot because that’s how it looks by the time we see it, long after it’s done its dirty work. While it’s active, though, it has ample moisture. It’s associated more with conifers, and you may recognize its blocky, brown, crumbly signature inside a windthrown tree. Eighty percent of wood-rot fungi are in the white-rot club, a thorough bunch able to eat lignin, the resilient “rebar” of wood, as well as carbohydrates. White rots are more common on hardwoods.</p>
<p>Over time, the biomass of these organisms will increase to the point that they send out fruiting bodies, spore-bearing conks that we’ve undoubtedly seen in the woods. <em>Fomitopsis pinicola</em> is a brown-rot fungus which produces a shiny red-belted conk, while <em>phellinus tremulae</em>, a white-rot, results in the hoof-shaped conk sometimes found on poplars.</p>
<p>Pileated woodpeckers aren’t after your tree; they’re pursuing ant colonies. In turn, ants don’t ruin your tree, but signal the presence of advanced decay within. Using insecticide on the ants will put all sorts of wildlife at risk, and is unlikely to eradicate the colony. Most importantly, it will do nothing to slow the inexorable march of internal decay.</p>
<p>Years ago I helped extricate a massive white pine from the attic of a house. It had snapped at about 30 feet and crushed the roof, harpooning good-size branches into the bedrooms below. It failed because of decay which had begun at an old wound and advanced. The ants present were but a symptom; if only a woodpecker had alerted the homeowner to the situation, disaster might have been averted.</p>
<p>If you see woodpeckers “vandalizing” your tree, be aware that decay lurks inside. You may want an arborist to evaluate it for mechanical integrity and overall health. Heartwood decay doesn’t always mean a tree is doomed, but if it’s destined to fall, best that it happens in a controlled fashion.</p>
<p>Regionally, around 40 bird species depend in some way on tree cavities. Primary excavators like flickers, woodpeckers, and chickadees significantly reduce forest-pest populations during winter as they feed on insect larvae, pupae, and adults. Feeding sites and abandoned nest cavities are used by tree swallows, wrens, kestrels, owls, and many other resident and migratory birds.</p>
<p>Because snags are critical to such species, it’s highly beneficial to leave dead forest trees standing when possible. Lower trunks of residential trees can be left when safety concerns allow. Not only does this provide key habitat, you may get a chance to observe bird species you otherwise wouldn’t see.</p>
<p><em>Paul Hetzler is an ISA-Certified Arborist. He avoids trees and lollipops that have soft centers.</em></p>Conspiracy of Leaf Color-Changetag:cornellforestconnect.ning.com,2020-09-12:6448444:BlogPost:372042020-09-12T10:49:43.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Fall Color Conspiracy</p>
<p>Conspiracy hypotheses (or theories, as we like to call them, since “hypotheses” cannot be uttered without a lisp) seem to multiply unfettered these days, so I feel awkward birthing yet another. But you may be intrigued to learn that the wide spectrum of color in the region’s fall foliage is largely the result of a Depression-era project implemented by the Hoover Administration.</p>
<p>We live in one of the few places on Earth where trees produce such a…</p>
<p>Fall Color Conspiracy</p>
<p>Conspiracy hypotheses (or theories, as we like to call them, since “hypotheses” cannot be uttered without a lisp) seem to multiply unfettered these days, so I feel awkward birthing yet another. But you may be intrigued to learn that the wide spectrum of color in the region’s fall foliage is largely the result of a Depression-era project implemented by the Hoover Administration.</p>
<p>We live in one of the few places on Earth where trees produce such a phantasmagoria of color. If you’ve been to Europe in autumn, or even out West, you know that the range of color is much more limited than here. Most green plants have varying amounts of yellow (xanthophylls) and orange (carotenoids) molecules, but you’d have to visit northern China to see anything close to the mélange of anthocyanins – that is to say, the burgundy, coral, crimson, raspberry, ruby, salmon, and scarlet hues – that the Northeast offers.</p>
<p>We’re taught in school that green chlorophyll masks pigments already within leaves. In fall, trees deposit wax between twigs and leaves to seal the vascular links. This kills chlorophyll, exposing underlying colors. But reds and purples are definitely not hiding beneath green chlorophyll.</p>
<p>Here’s my theory or hypotenuse or whatever:</p>
<p>For millennia, fall leaves were mainly orange, with little red or yellow. During the Depression, President Herbert Hoover tried to attract wealthy European tourists here, tasking the National Science Foundation with augmenting the leaf-color palette of New England. This partly successful initiative was called the Hoover Omnibus Anthocyanin and Xanthophyll project, or HOAX.</p>
<p>OK, to my knowledge, governments haven’t manipulated leaf color. But anthocyanins – reds and purples –don’t lurk inside green leaves, waiting for the big reveal when chlorophyll croaks.</p>
<p>Anthocyanins are large, complex organic molecules which take a lot of energy for a plant to synthesize. While relatively few tree species produce red fall colors, sugar and soft maples are renowned for their ruddy foliage. Some oaks produce deep scarlets, and dogwood and white ash can make intense red-purple hues.</p>
<p>Plants often invest in these compounds to protect emerging leaves in spring, as chlorophyll is vulnerable to UV-light damage in cool conditions. It’s chlorophyll suntan lotion. As foliage matures, plants quit making these expensive molecules. Early-season outlays make sense. But why do some trees spend energy now when they should be hoarding it for springtime?</p>
<p>Notorious for being frugal and pragmatic, trees don’t dip into their savings without good cause. Few hypotheses (theories are evidence-based, e.g. the theory of gravity; hypotheses are what jam the Internet) exist on why trees use precious reserves to shield dying chlorophyll while they’re hard at work making abscission layers to kill said chlorophyll. “Fall suntan lotion” seems an absurd explanation.</p>
<p>Another idea is that a maple’s (for instance) red leaves change soil conditions to favor its species. Certain plant-made chemicals can inhibit growth rates or seed germination of competitors, something known as allelopathy. Problem is, anthocyanins aren’t very good at this. A truly convincing rationale has yet to be found.</p>
<p>I don’t know why trees make red in the fall, and an honest biologist will admit they’re not quite sure either. Conspiracy or mystery, I’m just grateful for our autumn display.</p>
<p><em>An ISA-Certified Arborist since 1996, Paul Hetzler cooks up wild hypotheses in his spare time.</em></p>Learning to Speak Pinetag:cornellforestconnect.ning.com,2020-08-29:6448444:BlogPost:369122020-08-29T13:56:04.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Pine Whisperers</p>
<p>The term psithurism (sith-er-izm) doesn’t exactly roll off the tongue, but it’s not meant to. The word, from the Greek <em>psithuros</em> (whisper), indicates the melody that rolls off pine needles in a gentle wind. It also means the sound of “proper” leaves shaking in the treetops. Obviously, we need another word, because these two things – whispering pines and rustling leaves – may both soothe us, but they sound quite different.</p>
<p>In our little home in the…</p>
<p>Pine Whisperers</p>
<p>The term psithurism (sith-er-izm) doesn’t exactly roll off the tongue, but it’s not meant to. The word, from the Greek <em>psithuros</em> (whisper), indicates the melody that rolls off pine needles in a gentle wind. It also means the sound of “proper” leaves shaking in the treetops. Obviously, we need another word, because these two things – whispering pines and rustling leaves – may both soothe us, but they sound quite different.</p>
<p>In our little home in the Gatineau hills of Québec, we’re lucky that the house is shielded on the west by an unusually large and spreading yellow birch. One breezy morning when the windows were open, my wife remarked how different the birch sounded in the wind compared to the sugar maple, which is on the other side of the house. When I paid attention, it was clear she was right: the birch had a softer tone than the maple. I laughed that a city girl should make an observation that a longtime arborist had not.</p>
<p>In my defense, the matter of arboricultural acoustics had not escaped me entirely. The sound of a breeze passing through a poplar grove is unique. Everyone who’s had the pleasure of hearing this will probably have their own depiction, but I liken it to very distant applause, or the imagined noise of a thousand dragonflies passing overhead as their gossamer wings touch one another.</p>
<p>My curiosity piqued, I then searched in vain for some kind of catalog which described the sound of wind in trees, listed by species. Evidently, no one has yet been sufficiently bored or compulsive (or both) to undertake such a project.</p>
<p>Some other interesting things came up, however. I stumbled upon a beautiful passage written by a 12<sup>th</sup> century Chinese scholar named Liu Chi. Of course I would’ve had no idea what it said, but luckily it was a translation. Here is an excerpt from Liu Chi’s love letter to pine psithurism:</p>
<p>“Among plants and trees, those with large leaves have a muffled sound; those with dry leaves have a sorrowful sound; those with frail leaves have a weak and unmelodic sound. For this reason, nothing is better suited to wind than the pine. Listening to it can relieve anxiety and humiliation, wash away confusion and impurity, expand the spirit and lighten the heart, make one feel peaceful and contemplative, cause one to wander free and easy through the skies and travel along with the force of Creation.”</p>
<p>Wow – if that doesn’t make you want to run right out and sit in a pine grove, nothing will.</p>
<p>Not only do trees wash away our confusion as they whisper to us, they also quiet our voices. And the din from our motor vehicles. Many people notice how much farther sound seems to travel in the fall after all the leaves are off. Because vegetation helps dampen sound, urban planners and engineers try to incorporate noise barriers in the form of trees in order to make their cities more livable.</p>
<p>A buffer which is between 15 and 30 metres wide and densely planted in trees will reduce noise by as much as 8 decibels. When the same size tree buffer is atop a four-metre tall berm, noise falls off between 10 and 15 decibels. This may not seem like much, but it can make the difference between ambient noise with long-term harmful consequences and noise that is safe to live with.</p>
<p>Species and size make a difference as well. Deciduous trees are most effective, but conifer species are generally used so that the benefit is year-round. Also, younger trees are better at dampening sound than mature ones. Barrier effectiveness increases until trees are about 12 metres tall, after which their benefit slowly declines. For this reason, understory species as well as shrub borders along barrier edges are important. Hopefully the wind in these buffer-strip pines can still be discerned on occasion.</p>
<p>I urge everyone to get out as soon as possible to “relieve anxiety and humiliation, wash away confusion and impurity, expand the spirit and lighten the heart” by listening to breeze-tossed pines. Also, please help think of a companion word to psithurism that we can apply strictly to deciduous trees. Rustling just isn’t the same as whispering.</p>
<p><em>Paul Hetzler is an ISA-Certified Arborist and a member of the Society of American Foresters, the Canadian Institute of Forestry, ISA-Ontario, and NYS Arborists. He needs to listen more to his wife, as well as pine trees.</em></p>
<p> </p>Tree Defensestag:cornellforestconnect.ning.com,2020-08-22:6448444:BlogPost:370012020-08-22T19:24:01.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Tree Protection</p>
<p>Paul Hetzler, ISA Certified Arborist</p>
<p>As someone whose job it is to help preserve trees, I find it ironic that in nearly every case I am saving them from us. We injure their root systems, whack them with mowers and weed-eaters, plant them too deeply, and do many other things which jeopardize their health. It would be terrifying if they could fight back in the manner of Tolkien’s magical Fangorn Forest. For one thing, tree work would be a lot more dangerous than…</p>
<p>Tree Protection</p>
<p>Paul Hetzler, ISA Certified Arborist</p>
<p>As someone whose job it is to help preserve trees, I find it ironic that in nearly every case I am saving them from us. We injure their root systems, whack them with mowers and weed-eaters, plant them too deeply, and do many other things which jeopardize their health. It would be terrifying if they could fight back in the manner of Tolkien’s magical Fangorn Forest. For one thing, tree work would be a lot more dangerous than it already is.</p>
<p>But trees are able to defend themselves against pests and diseases. They have both protective structures and protective processes, comparable in some ways to our immune systems. Thanks in large part to research done from the mid-1960s to the early 1980s by Dr. Alex Shigo of the US Forest Service, we know a great deal more about the way trees protect themselves than we did fifty years ago.</p>
<p>We have long known how, just as our skin keeps harmful bacteria on our outsides, bark acts as a shield against tree pathogens. Since they don’t have the luxury of mobility to avoid hazards, trees need thicker “skin” than we do. Layers of living and non-living tissues protect tree trunks, roots and branches from mechanical injury, drying out, as well as from diseases.</p>
<p>But when something breaches this first line of defense – tears through the bark – what happens internally is fascinating. When an injury occurs, a tree will convert some of its stored sugars to make an array of defensive chemicals. It then distributes and deposits these compounds in a specific pattern internally around the wound. Dr. Shigo was the first to document this pattern, which he called CODIT – compartmentalization of decay in trees.</p>
<p>In making these CODIT compartments, trees make four different chemical walls – two circular, one radial, and one more or less flat horizontally. Describing these walls is a bit esoteric, or maybe boring, but if you’re interested in the details, this US Forest Service document <a href="https://www.nrs.fs.fed.us/pubs/misc/ne_aib405.pdf">https://www.nrs.fs.fed.us/pubs/misc/ne_aib405.pdf</a> is superb.</p>
<p>I’d like to point out that wound closure, often referred to as “healing over,” is not closely related to how much decay will occur. The extent of rot depends on how effectively a tree can wall off infections. Closure is good in as much as the vascular system no longer needs to detour around a wound, but closure doesn’t protect against internal decay if the tree is too weak to chemically protect itself.</p>
<p>The success of this walling-off depends a lot on the species. Hard maple and white oak, for instance, can generate a strong CODIT response. Poplar and willow, on the other hand, barely manage to form any chemical walls, while species like red oak and soft maple do a mediocre job of it.</p>
<p>Overall tree vitality is another important factor. We know that if we’re chronically stressed, malnourished, poorly hydrated or otherwise run down, we are a lot more vulnerable to illness. Even a sugar maple may not be able to form strong chemical walls if it’s in a weakened state. By definition, landscape trees are stressed as compared to their forest-dwelling cousins. A street tree is worse-off yet, faced with reflected heat, limited root space, road salt, air pollution and more.</p>
<p>And of course the size of the injury makes a difference. Even a happy, healthy tree can have its defenses overwhelmed by a large wound. We know that many times, the tree loses its battle against decay.</p>
<p>Much less is known about the way trees react to insect pests. We’re aware that trees defend against insect pests by engaging their internal chemistry set to synthesize compounds, known to scientists as Bad Tasting Stuff, to repel them (insects, that is – not scientists). In many cases they seem able to tailor their natural repellent to a specific bug. But these designer chemicals aren’t perfect – just look at what tent caterpillars and gypsy moths can do. </p>
<p>It has recently come to light that trees have a kind of distant early-warning system. Apparently they can signal one another about what type of pest has arrived on the scene to munch foliage. This communication happens under the ground through root grafts, though the mechanism is not well-researched. Some biologists also think that airborne chemicals might also carry messages related to pests, or even diseases.</p>
<p>Trees also have protective structures called branch collars, located at the base of every branch. Branch collars are more adept than regular trunk tissue at producing fungicides to form protective barriers. This collar is usually a slightly enlarged “donut” ring at the base of the branch – it’s essential not to remove it when pruning. Especially on hardwoods, pruning cuts must never be flush with the trunk; rather they should be made just outside the branch collar.</p>
<p>You can help maximize your tree’s “immune system” by watering during dry spells, mulching out to the dripline, and keeping vehicles out of the root zone. In return, your tree will help keep you in optimal health by offering shade, beauty and companionship.</p>
<p><em>Paul Hetzler is a Certified Arborist and former Cornell Cooperative Extension educator.</em></p>The End of Sugar Maples?tag:cornellforestconnect.ning.com,2020-08-19:6448444:BlogPost:368062020-08-19T12:50:53.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Maples on the Move</p>
<p>Unless trees are wondrously furtive, I’m pretty sure they don’t travel. But their species ranges can. A report from the US Forest Service’s Northern Research Station indicates that due to climate change, 70% of Eastern tree species have already begun to shift their ranges to the north. The authors admit this is not a new trend, but rather the hastening of an old one:</p>
<p>“Tree ranges in ancient times certainly shifted according to changing climates, but the…</p>
<p>Maples on the Move</p>
<p>Unless trees are wondrously furtive, I’m pretty sure they don’t travel. But their species ranges can. A report from the US Forest Service’s Northern Research Station indicates that due to climate change, 70% of Eastern tree species have already begun to shift their ranges to the north. The authors admit this is not a new trend, but rather the hastening of an old one:</p>
<p>“Tree ranges in ancient times certainly shifted according to changing climates, but the changes were relatively slow. Fossil plant and pollen records show tree species’ ranges shifted northward a rate of 50 km per century as temperatures rose after the retreat of the North American ice cap. Such shifts are sometimes called ‘tree migration,’ but they are really changes in a species’ population density and range. The more accurate term is ‘tree range migration.’”</p>
<p>OK, so Mother Nature apparently moved tree species an average of 50 kilometers (31 miles) every hundred years. This helps put in perspective a study report entitled “Shifting with climate? Evidence for recent changes in tree species distribution at high latitudes,” published in the journal <em>Ecosphere</em> in July 2014.</p>
<p>The study, conducted by Laura Boisvert-Marsh, Catherine Périé and Sylvie de Blois, examined 11 tree species common to eastern North America: Balsam Fir, Red Maple, Sugar Maple, Yellow Birch, Paper Birch, American Beech, Hop-Hornbeam, White Spruce, Black Spruce, Trembling Aspen, and Eastern White Cedar. Specifically, they looked at range alterations between 1970 and 2014.</p>
<p>I admit that this is a highly technical paper, and I may have pulled a muscle trying to understand it all. The study assessed changes at several different latitude points, and also compared sapling redistribution with that of larger trees. In addition, the authors noted that factors other than climate change no doubt had an effect on tree range migration as well.</p>
<p>However, their report concluded that “Five out of the eleven species examined (Sugar Maple, Red Maple, Paper Birch, American Beech, and Trembling Aspen) showed significant northward migration.” What stood out to me was that taken as a whole, they found that since 1970, “The average overall [range] shift was 111.2 km [69 miles] at 49° N.” Contrast that with historical natural movement of 50 km in a century.</p>
<p>Scientists at the US Forest Service believe that by the end of the century, at least 8, and possibly as many as 27, tree species will have moved 200 kilometers (124 miles) north. In fact, they project that in the year 2100, sugar maple will exist almost exclusively in Canada.</p>
<p>There may well be exceptions. It’s possible that enclaves of species which are projected to move out of the region will be able to survive in isolated nooks and crannies of the Adirondacks and other similar terrain. Variation of slope and aspect in the mountains creates “Climate Refugia,” micro-habitats conducive to a broad spectrum of tree species. These refugia resist change – they are not immune to it, but adjustments happen more slowly there.</p>
<p>Change is sometimes good, but it’s always scary. Luckily, we do have agency in determining our future. According to the Canadian Association for Educational Resources, “By 2100 the atmospheric CO<sub>2</sub> concentration (the gas responsible for most temperature change) will be between 540 and 970 ppm,” depending how much carbon dioxide we pump into the air.</p>
<p>The huge discrepancy between those two numbers offers us a chance to slow the rate at which tree species march northward. It’s hard to feel motivated when we know our decisions are a drop in the pool. Well, drops matter. It takes something like 50 billion drops to fill an Olympic-size pool. If each Earthling coughed up (figuratively, please) 6.4 drops, it would be full.</p>
<p>No matter where we live, everyone has access to a dropper of some sort. Maybe it’s trading our 4X4 for a car with snow tires. Maybe it’s planting trees. Or biking to work, switching to LED bulbs, or any number of other small acts. We are all experts on what that might look like in our lives. Every drop makes it less likely the next generation will ask “Hey Grandma (or Grandpa), tell me that story again about when maples grew here.”</p>
<p><em>Paul Hetzler is an ISA-Certified Arborist and a member of the Society of American Foresters, the Canadian Institute of Forestry, ISA-Ontario, and NYS Arborists. At the moment, he has no plans to migrate farther north.</em></p>The End of Sugar Maples?tag:cornellforestconnect.ning.com,2020-08-19:6448444:BlogPost:367142020-08-19T12:50:50.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Maples on the Move</p>
<p>Unless trees are wondrously furtive, I’m pretty sure they don’t travel. But their species ranges can. A report from the US Forest Service’s Northern Research Station indicates that due to climate change, 70% of Eastern tree species have already begun to shift their ranges to the north. The authors admit this is not a new trend, but rather the hastening of an old one:</p>
<p>“Tree ranges in ancient times certainly shifted according to changing climates, but the…</p>
<p>Maples on the Move</p>
<p>Unless trees are wondrously furtive, I’m pretty sure they don’t travel. But their species ranges can. A report from the US Forest Service’s Northern Research Station indicates that due to climate change, 70% of Eastern tree species have already begun to shift their ranges to the north. The authors admit this is not a new trend, but rather the hastening of an old one:</p>
<p>“Tree ranges in ancient times certainly shifted according to changing climates, but the changes were relatively slow. Fossil plant and pollen records show tree species’ ranges shifted northward a rate of 50 km per century as temperatures rose after the retreat of the North American ice cap. Such shifts are sometimes called ‘tree migration,’ but they are really changes in a species’ population density and range. The more accurate term is ‘tree range migration.’”</p>
<p>OK, so Mother Nature apparently moved tree species an average of 50 kilometers (31 miles) every hundred years. This helps put in perspective a study report entitled “Shifting with climate? Evidence for recent changes in tree species distribution at high latitudes,” published in the journal <em>Ecosphere</em> in July 2014.</p>
<p>The study, conducted by Laura Boisvert-Marsh, Catherine Périé and Sylvie de Blois, examined 11 tree species common to eastern North America: Balsam Fir, Red Maple, Sugar Maple, Yellow Birch, Paper Birch, American Beech, Hop-Hornbeam, White Spruce, Black Spruce, Trembling Aspen, and Eastern White Cedar. Specifically, they looked at range alterations between 1970 and 2014.</p>
<p>I admit that this is a highly technical paper, and I may have pulled a muscle trying to understand it all. The study assessed changes at several different latitude points, and also compared sapling redistribution with that of larger trees. In addition, the authors noted that factors other than climate change no doubt had an effect on tree range migration as well.</p>
<p>However, their report concluded that “Five out of the eleven species examined (Sugar Maple, Red Maple, Paper Birch, American Beech, and Trembling Aspen) showed significant northward migration.” What stood out to me was that taken as a whole, they found that since 1970, “The average overall [range] shift was 111.2 km [69 miles] at 49° N.” Contrast that with historical natural movement of 50 km in a century.</p>
<p>Scientists at the US Forest Service believe that by the end of the century, at least 8, and possibly as many as 27, tree species will have moved 200 kilometers (124 miles) north. In fact, they project that in the year 2100, sugar maple will exist almost exclusively in Canada.</p>
<p>There may well be exceptions. It’s possible that enclaves of species which are projected to move out of the region will be able to survive in isolated nooks and crannies of the Adirondacks and other similar terrain. Variation of slope and aspect in the mountains creates “Climate Refugia,” micro-habitats conducive to a broad spectrum of tree species. These refugia resist change – they are not immune to it, but adjustments happen more slowly there.</p>
<p>Change is sometimes good, but it’s always scary. Luckily, we do have agency in determining our future. According to the Canadian Association for Educational Resources, “By 2100 the atmospheric CO<sub>2</sub> concentration (the gas responsible for most temperature change) will be between 540 and 970 ppm,” depending how much carbon dioxide we pump into the air.</p>
<p>The huge discrepancy between those two numbers offers us a chance to slow the rate at which tree species march northward. It’s hard to feel motivated when we know our decisions are a drop in the pool. Well, drops matter. It takes something like 50 billion drops to fill an Olympic-size pool. If each Earthling coughed up (figuratively, please) 6.4 drops, it would be full.</p>
<p>No matter where we live, everyone has access to a dropper of some sort. Maybe it’s trading our 4X4 for a car with snow tires. Maybe it’s planting trees. Or biking to work, switching to LED bulbs, or any number of other small acts. We are all experts on what that might look like in our lives. Every drop makes it less likely the next generation will ask “Hey Grandma (or Grandpa), tell me that story again about when maples grew here.”</p>
<p><em>Paul Hetzler is an ISA-Certified Arborist and a member of the Society of American Foresters, the Canadian Institute of Forestry, ISA-Ontario, and NYS Arborists. At the moment, he has no plans to migrate farther north.</em></p>Forget Covid -- Lyme is Worsetag:cornellforestconnect.ning.com,2020-05-05:6448444:BlogPost:357022020-05-05T14:12:07.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Ticked Off Again</p>
<p>It seems the price we pay for warm weather is the onset of bug bites. Clouds of mosquitoes suck the fun out of outdoor activities, but one bite from a deer (black-legged) tick can put you out of commission for the whole season – maybe longer.</p>
<p>As recently as a decade ago in northern NY State it was unusual to find deer ticks on you even after a long day outdoors. Technically an invasive species, the deer tick (<em>Ixodes scapularis</em>) is another gift from…</p>
<p>Ticked Off Again</p>
<p>It seems the price we pay for warm weather is the onset of bug bites. Clouds of mosquitoes suck the fun out of outdoor activities, but one bite from a deer (black-legged) tick can put you out of commission for the whole season – maybe longer.</p>
<p>As recently as a decade ago in northern NY State it was unusual to find deer ticks on you even after a long day outdoors. Technically an invasive species, the deer tick (<em>Ixodes scapularis</em>) is another gift from down south, having gradually moved north from the Mid-Atlantic and lower New England states. Generally speaking, they are now widespread in the northeastern US and southeastern Canada.</p>
<p>Deer ticks are arachnids, in the same family as spiders – smaller, but far more dangerous. They are known to vector Lyme disease and a slew of appetizing scourges, including babesiosis, erlichiosis, anaplasmosis, Powassan virus and more. It’s fairly common for a tick to transmit multiple diseases at the same time.</p>
<p>Our understanding of tick-borne illness has changed drastically in the past few years. If you have literature older than 2015, throw it out (tick literature – save your other books). As an example, Dr. Ninevah Zubcevic, a tick specialist who teaches at Harvard Medical School, contends that the red expanding “bull’s-eye” rash or erythema migrans, once considered the hallmark of Lyme, is actually rare, occurring in fewer than 20% of Lyme cases. Other credible sources put it even lower.</p>
<p>In 2014, the New York State Department of Health commissioned a tick study in four northern NYS counties. It concluded that about 50% of ticks were infected with <em>Borrelia</em> <em>burgdorferi</em>, the spirochete bacterium that causes Lyme (not <em>Lyme’s</em> – those are for mojitos and margaritas). This conflicts with older material suggesting a 20% deer-tick infection rate.</p>
<p>In addition, by 2016, researchers had identified two more deer tick-borne microbes in the genus <em>Borrelia</em>. These newbies, <em>B. miyamotoi</em> and <em>B. mayonii</em>, can give you a so-called “Lyme variant.” Sadly, blood tests don’t recognize these recently identified pathogens.</p>
<p>This isn’t to say we need to panic, though feel free if you like. Avoiding ticks would be the most effective course of action, but if you work or play out in the real world, that’s not always an option. The US Centers for Disease Control and Prevention (CDC) recommends using products with 20-30% DEET on exposed skin.</p>
<p>Clothing and footwear can be treated with 0.5% permethrin. Although I am not a fan of pesticides in general, I can’t say enough about how effective permethrin is. It not only repels ticks, it kills them within minutes. Another great thing is that it’s a once or twice per season application – it is reported to stay effective through at least 20 wash cycles. Always follow label instructions – permethrin is 2,250 times more toxic to ticks than to mammals, but it’s still a pesticide.</p>
<p>Out in the woods, never follow a deer trail. Treat your pets regularly with a systemic anti-tick product and/or tick collar so they don’t bring deer ticks into the home. Talk to your vet about getting your pets vaccinated against Lyme (sadly there is no human vaccine at the moment).</p>
<p>Check for ticks every evening after showering. They prefer hard-to-see places such as the armpits, groin, scalp, and the backs of the knees. Also look closely at the beltline and sock hem – they like to tuck into the edge of clothing.</p>
<p>If you find a tick has latched onto you, the CDC recommends grasping it with tweezers as close to the skin as possible and pulling straight up until it releases. You may have to pull hard if it has been feeding for some time. Use steady pressure – no sudden motions.</p>
<p>Do not use heat, petroleum jelly, essential oils or other home remedies – please! These treatments may get a tick to release, but they will also make it disgorge the entire contents of its gut into your bloodstream. Unless you want a disease injection, remove ticks the proper way.</p>
<p>Please note that mouthpart fragments usually remain in your skin afterward. This is not a problem, and will not increase the risk of illness. Apply a topical antibiotic – your body will expel the fragments.</p>
<p>While it was once thought ticks did not transmit Lyme until they had been attached for 36 to 48 hours, experts now say that while you definitely have 24 hours, beyond that you are at risk. But other illnesses can be transmitted within minutes. Hooray, right?</p>
<p>Early symptoms of Lyme disease vary widely – wildly – from person to person. Early Lyme effects may include severe headache, chills, fever, extreme fatigue, joint pain, night sweats, or dizziness. But the first signs could be heart palpitations. Lyme may present with sudden and marked confusion as its first symptom. Too many times it has been mistaken for dementia, and has also been misdiagnosed as depression, and even schizophrenia.</p>
<p>If you’ve been bitten by a deer tick and have any such symptoms, call a doctor right away. Prompt treatment is critical – Lyme can cause irreversible arthritis, and cardiac impairment, or neurological damage. Most people respond well to treatment, but a few may take months, sometimes more than a year, to recover. It’s a shame how little is known about “Post-Lyme Syndrome” or “Chronic Lyme” beyond that they may involve autoimmune responses, and they devastate the lives of those afflicted.</p>
<p>An important point is that the Lyme titer or Western blot test is NOT a yes-or-no assay. Each lab chooses how sensitive – i.e., effective – to make its Western blot. Of the 36 immunoglobulin “bands” identified by the CDC for a complete Lyme test, labs typically check for seven to twelve bands.</p>
<p>Individual labs also decide how to interpret the tests. One lab might count two positive bands as a yes-result, while the next may require three bands. Follow this logic: Two bands present – “Stop whining and get back to work.” Three bands – “OMG you poor sick puppy! Take these pills and rest a few weeks.” You get the yes-or-no call, sure. But you don’t get to see your score card unless you insist.</p>
<p>Also, the Western blot is known to have at least a 36% false-negative rate (<em>Journal of Clinical Infectious Diseases</em>, 07/2008). And according to lymedisease.org, “56% of patients with Lyme disease test negative using the two-tiered testing system recommended by the CDC. (Stricker 2007)”</p>
<p>To recap, deer ticks can mess up your life in a big way. Use permethrin on clothes and shoes, check for ticks daily and remove them promptly. Very few Lyme cases involve a rash, and symptoms can be all over the map. Find a doctor who will treat you based on clinical presentation, because testing is unreliable, to put it nicely. For lots more great information, peruse the Canadian Lyme Disease Foundation website at <a href="https://canlyme.com/">https://canlyme.com/</a></p>
<p>Now, get ticked off and stay that way!</p>
<p><em>Paul Hetzler is a naturalist and an ISA-Certified Arborist. He lives with his wife in Val-des-Monts, Québec.</em></p>Winter Buds, Sap Seasonstag:cornellforestconnect.ning.com,2020-02-29:6448444:BlogPost:354202020-02-29T18:39:43.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p><a href="https://www.northcountrypublicradio.org/news/story/40723/20200229/using-buds-to-id-trees-in-winter-and-surviving-on-sap?fbclid=IwAR3_77WrfktZVeXSDTv60A_znUHQY1dkMZt8SrrKnBfHqlmzmF0SJMvV-yI">https://www.northcountrypublicradio.org/news/story/40723/20200229/using-buds-to-id-trees-in-winter-and-surviving-on-sap?fbclid=IwAR3_77WrfktZVeXSDTv60A_znUHQY1dkMZt8SrrKnBfHqlmzmF0SJMvV-yI</a></p>
<p><a href="https://www.northcountrypublicradio.org/news/story/40723/20200229/using-buds-to-id-trees-in-winter-and-surviving-on-sap?fbclid=IwAR3_77WrfktZVeXSDTv60A_znUHQY1dkMZt8SrrKnBfHqlmzmF0SJMvV-yI">https://www.northcountrypublicradio.org/news/story/40723/20200229/using-buds-to-id-trees-in-winter-and-surviving-on-sap?fbclid=IwAR3_77WrfktZVeXSDTv60A_znUHQY1dkMZt8SrrKnBfHqlmzmF0SJMvV-yI</a></p>Forest Bathingtag:cornellforestconnect.ning.com,2020-02-23:6448444:BlogPost:356222020-02-23T13:43:43.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Trees by the Tub-full</p>
<p>Paul Hetzler</p>
<p>A hot bath is an age-old remedy for calming our nerves, but science has now shown that a better tonic for anxiety and stress is bathing in the forest, fully dressed. True story. Of course, a few details would be helpful.</p>
<p>In a blinding flash of the obvious, research has proven that being around trees makes us feel better. To be fair, the scientific process requires measurable evidence, so in this case, real-time brain imaging with fMRI…</p>
<p>Trees by the Tub-full</p>
<p>Paul Hetzler</p>
<p>A hot bath is an age-old remedy for calming our nerves, but science has now shown that a better tonic for anxiety and stress is bathing in the forest, fully dressed. True story. Of course, a few details would be helpful.</p>
<p>In a blinding flash of the obvious, research has proven that being around trees makes us feel better. To be fair, the scientific process requires measurable evidence, so in this case, real-time brain imaging with fMRI and PET scans, as well as blood-cortisol levels, heart rate and blood pressure, were used in a host of studies which showed that being immersed in nature does us a lot of good, even if we’re skeptical.</p>
<p>We are blessed with an abundance of natural beauty, so we’re ahead of the curve in a new fad headed our way called “forest bathing.” In Japan this has been going on for decades, but it has recently arrived in trend central, California. Apparently in Los Angeles, forest bathing is an organized activity led by trained, certified forest-bathing guides. I’m not saying that’s wrong, but really, all you have to do is step into a forest for 20 minutes or more. That’s it. No fees, no equipment to buy, and even if you just sit there inert, you’ll reap the benefits.</p>
<p>If you think this is much ado about nothing, consider that a 1994 EPA-sponsored study revealed that the average American spends 93% of their time indoors. And that was before the Internet and smart phones. In light of this, and the mounting evidence of how important nature is to our health, around 500 mainstream medical doctors in the US now actually prescribe walks in the woods (though since most of our population resides in urban areas, a park has to suffice).</p>
<p>One early adopter is David Sabgir, a MD Columbus, Ohio-based cardiologist. He founded Park Rx America, a “non-profit organization whose mission is to decrease the burden of chronic disease and increase health and happiness by virtue of prescribing Nature during the routine delivery of healthcare.”</p>
<p>The positive effect trees have on our health is not a vague concept – it is being quantified, and the results are staggering. Given that the USA has by far the most expensive health care system in the world, the US government is very interested in potential health-care cost reduction which can be realized through exposure to nature. Dr. Kathy Wolf of the University of Washington calculates the annual savings to be at least $2.7 billion, and possibly as much as $6.7 billion.</p>
<p>Early in the history of public zoos, keepers noticed that animals deprived of a naturalistic environment tended to get violent, and became ill more often. The same holds true for the human animal. Dr. Frances Kuo from the University of Illinois at Champaign-Urbana says humans living in landscapes that lack trees or other natural features undergo patterns of social, psychological and physical breakdown that are strikingly similar to those observed in other animals that have been deprived of their natural habitat.</p>
<p>The advantages of experiencing nature are myriad. In a Feb. 2014 article in the guardian.com, Richard Louv, author of <em>Last Child in the Woods</em>, tells how patients in rooms with tree views had shorter hospital stays and needed less pain medication compared to patients without a natural vista. College students do better on cognitive tests when their dorm windows view natural settings, and after just an hour in the woods, memory performance and attention span improves 20%.</p>
<p>Dr. Kuo’s research finds that elderly adults tend to live longer if their homes are near a park or other green space, regardless of social or economic status, and researchers at the University of Rochester report that exposure to the natural world improves one’s capacity to nurture healthy relationships.</p>
<p>Scandinavian countries quietly adopted this idea long ago. In Norway there’s a movement called <em>Friluftsliv</em>, “open-air life,” which kind of boils down to forest bathing. They even have a law, <em>Allemannsrett</em>, or “all humankind’s right,” which allows anyone to walk on rural land not under cultivation.</p>
<p>We need to help the public regard trees as an essential part of human health, and to act accordingly. I encourage everyone to start forest-bathing as soon as possible. For that over-the-top stress, however, perhaps you could arrange to have your tub moved into the woods to get the best of all worlds.</p>
<p>For further information, go to <a href="https://www.webmd.com/balance/news/20190611/forest-bathing-nature-time-hot-health-advice">https://www.webmd.com/balance/news/20190611/forest-bathing-nature-time-hot-health-advice</a></p>
<p><em>An ISA-Certified Arborist since 1996, <strong>Paul Hetzler</strong> wanted to be a bear when he grew up, but failed the audition. Having gotten over much of his self-pity concerning that unfortunate event, he now writes essays about nature. His book</em> “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” <em>is available on amazon.</em></p>
<p> </p>Re-Thinking Black Locusttag:cornellforestconnect.ning.com,2020-02-23:6448444:BlogPost:355312020-02-23T12:38:02.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Not Plagued by Black Locusts</p>
<p>Paul Hetzler, ISA Certified Arborist</p>
<p>Sometimes I wonder if the Biblical plagues of ancient Egypt have lingered in one form or another. Blooms of toxic algae, which occasionally turn water a blood-red color, are on the increase. Gnats and lice have been supplanted by deer ticks, which I’d argue are even worse, and there is no shortage of hail in season. Frog outbreaks may not have occurred since Pharaoh’s time, but poisonous cane toads imported to…</p>
<p>Not Plagued by Black Locusts</p>
<p>Paul Hetzler, ISA Certified Arborist</p>
<p>Sometimes I wonder if the Biblical plagues of ancient Egypt have lingered in one form or another. Blooms of toxic algae, which occasionally turn water a blood-red color, are on the increase. Gnats and lice have been supplanted by deer ticks, which I’d argue are even worse, and there is no shortage of hail in season. Frog outbreaks may not have occurred since Pharaoh’s time, but poisonous cane toads imported to Australia are now running amok there, decimating all manner of native animals. And currently, swarms of locusts are causing great hardship in Somalia, Ethiopia, and Kenya.</p>
<p>Here in the Northeast, we are blessedly free of the kind of swarm-feeding grasshoppers that continue to cause suffering in Africa. Nonetheless, locusts have become such a problem that in 2014 the New York State Department of Environmental Conservation (NYSDEC) declared the locust a Regulated Invasive Species, meaning it “cannot be knowingly introduced into a free-living state.” In other words, locusts are only legal in an environment from which they can’t escape.</p>
<p>As usual this is a deceptive opening, for which I sincerely do not apologize. In our neck of the woods, the locusts which concern the NYSDEC and other conservation groups are black locusts (<em>Robinia pseudoacacia</em>), trees having origins in the Central-Eastern US.</p>
<p>A member of the pea family, the black locust matures at 60-80 feet tall, and makes its own nitrogen supply by “fixing” atmospheric nitrogen via symbiotic soil bacteria on root nodules. This free fertilizer gives locusts an advantage on nutrient-poor sites. Additionally, they are experts at self-cloning through root suckers or sprouts, much like poplars do. Especially in poor soil, this can lead to near-monoculture locust groves. Locust gives itself yet another black eye by having sharp thorns able to slash clothing and skin.</p>
<p>By definition, an invasive species is from another ecosystem (typically overseas), is able to thrive and replace native competitors, and causes significant economic, ecological, or human-health effects. Examples like the emerald ash borer, Asian longhorned beetle, Japanese knotweed, and swallow-wort clearly fit that bill, causing billions in damage, but devoid of redeeming qualities.</p>
<p>I think it’s wrong to paint all invasives with the same brush. For one thing, given that there are more than 400 invasive species in NY State alone, the bristles would wear out long before you could finish the job. It is curious that black locust, which by some accounts was spread from its native range 500 or more years ago, has only been dubbed invasive in the past decade or so. On prairies, and grassland-bird habitats generally, it can indeed be a problem. However, there are many other locales where it is clearly beneficial, economically as well as ecologically.</p>
<p>Dr. Robert P. Barrett of Michigan State University, who has been researching black locust trees since 1978, writes that “…due to flavonoids in the heartwood, [black locust wood] can endure for over 100 years in the soil.” Move over, redwood, which only lasts 30 years. Rot-resistance is what makes the demand for locust fence posts far exceed the supply at this time.</p>
<p>This quality is the reason black locust was imported to Europe in the early 1600s. Over time, European foresters have done a superior job of selecting traits such as straight, uniform trunks, and today the best sources for good locust stock are said to be found in Hungary. European farmers quickly realized locust leaves were a valuable source of protein for ruminant livestock, and to this day it is used as such in Europe as well as in many Asian countries to which black locust was exported.</p>
<p>Writing for the Cornell Small Farms Program, Extension Specialist Steve Gabriel notes that beekeepers value the black locust. Its flowers are an important source of nectar for bees, and the resultant honey, sometimes called acacia honey, is much sought-after. Gabriel also writes that black locust is used as a “nurse crop” for walnut orchards because it puts nitrogen into the soil, and is not affected by the toxin released from walnut roots.</p>
<p>Another point is that black locust is ideal for reclaiming gravel pits, strip mines and other tough environments. In the conclusion of his 1990 paper “Black Locust: A Multi-purpose Tree Species for Temperate Climates,” Dr. Barrett says “As one of the most adaptable and rapid-growing trees available for temperate climates, it will always be valued for erosion control and reforestation on difficult sites. Vast new forests of rapid-growing species may be needed to slow the accumulation of CO<sub>2</sub> in our atmosphere.”</p>
<p>Not only does black locust grow quickly on impoverished sites, its wood has the highest heat value per volume of any tree in the Northeast. Wood-BTU charts seldom agree, probably due to variations in growing conditions from place to place which affect wood quality, but black locust is often rated at between 28 million and 29.7 million BTUs per cord. This puts it on par with, or slightly better than, hickory. Trials conducted by the Southern Forest Biomass Working Group found that of any tree species tested, black locust was the cheapest to grow and yielded the greatest heat value, with about 200 million BTUs per acre after five years.</p>
<p>Commercially, black locust is in high demand for mine timbers, railroad ties, boat-building, and for many applications where rot-resistance is important. According to wood-database.com, “Black Locust is a very hard and strong wood, competing with Hickory (<em>Carya</em> genus) as the strongest and stiffest domestic timber, but with more stability and rot resistance.”</p>
<p>The International Union for the Conservation of Nature considers it one of the most sustainable and ecologically-friendly sources of timber, and The National Wildlife Foundation says it is host to 57 species of butterflies and moths. It can be used to quickly reforest sites that would otherwise become long-term habitat more pernicious invaders like buckthorn, dog-strangling vine, and exotic honeysuckle species. All good reasons to strike <em>Robinia pseudoacacia</em> from the list of plagues in many locations.</p>
<p><em>An ISA-Certified Arborist since 1996, <strong>Paul Hetzler</strong> wanted to be a bear when he grew up, but failed the audition. Having gotten over much of his self-pity concerning that unfortunate event, he now writes essays about nature. His book</em> “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” <em>is available on amazon.</em></p>Avoiding Split Treestag:cornellforestconnect.ning.com,2019-11-20:6448444:BlogPost:350042019-11-20T01:19:35.000ZPaul J Hetzlerhttps://cornellforestconnect.ning.com/profile/PaulJHetzler429
<p>Wishbone Trees</p>
<p>Breaking a wishbone, some believe, may impart good fortune to the person left with the bigger half. When a tree splits, though, everyone loses. Fortunately, by engaging a tree-care professional, we can control whether or not a Y-shaped tree splits.</p>
<p>Growing up, our family’s Thanksgiving traditions were well balanced. First we ate a lot, but after dinner my two brothers and I engaged in vigorous exercise for thirty minutes or so. That’s usually how long it took to…</p>
<p>Wishbone Trees</p>
<p>Breaking a wishbone, some believe, may impart good fortune to the person left with the bigger half. When a tree splits, though, everyone loses. Fortunately, by engaging a tree-care professional, we can control whether or not a Y-shaped tree splits.</p>
<p>Growing up, our family’s Thanksgiving traditions were well balanced. First we ate a lot, but after dinner my two brothers and I engaged in vigorous exercise for thirty minutes or so. That’s usually how long it took to tussle over which two boys would get to break the turkey’s wishbone. Of course sometimes it backfired if the loser cried loudly enough that they got promoted to the wishbone-pulling team. Following the event, further “exercise” might ensue if there were strong feelings about the fairness of said match. Luckily, bone breakage was restricted to cooked poultry, and we brothers remain on good terms.</p>
<p>The Y-shaped furcula or wishbone, as normal folks call it, is unique to birds, and breaking it to determine who gets the larger of the two halves – and thus the wish or good luck – goes back a few thousand years. Reportedly there are subtle ways to influence who gets the better half, but these were unknown to us as kids.</p>
<p>Even if your Thanksgiving rituals do not include breaking a wishbone, we’ve all seen trees that fork in a similar way. Unlike a wishbone, however, there is no lucky outcome for anyone in such situations, because trees which divide into two roughly equal-size stems or trunks are doomed to split. The narrower the angle at which the two trunks divide, the weaker the union is, but the chances of splitting always increase with age.</p>
<p>To some extent, a propensity for multiple trunks is genetic. In a forest environment, trees with poor structure split during wind or ice-load events. It is nature’s way of picking trees with better genetics (or luck, sometimes) to live longer and seed future forests. This selection process is great for woodlands, but not for trees growing in our yards, streets and parks.</p>
<p>We are the “unnatural selection” force responsible for choosing which trees get planted, and where. It takes a lot of effort, expense and time to have a shade tree reach maturity, and we want to keep them around as long as possible.<br/>All trees have imperfections, the vast majority of which are benign. But some can be dangerous.</p>
<p>To avoid breakage of large limbs, and associated flying lawsuits and debris, trees with obvious defects are often removed as a matter of course. Since many tree problems are a result of our activities, it hardly seems fair to send a mature shade tree to that great arboretum in the sky if we can find an alternative.</p>
<p>Somewhere there must be a cute little town called Narrow Forks. Where trees are concerned, this is the name of a problem that occurs when the angle of attachment between two competing (codominant) trunks is acute, rather than cute. The strongest attachments are open and closer to U-shaped. Narrow forks or unions get weaker with age and eventually fail. Major, often catastrophic, splits occur during ice storms, microbursts and other violent weather.</p>
<p>When you have a priceless target such as a Fabergé egg or a children’s play area that is within striking distance of a “wishbone” tree, corrective action is needed. Thanksgiving to Easter is the best period in which to have your landscape trees professionally evaluated, because tree architecture is easier to see when the leaves are off. A tree in very bad shape may need to be removed, but oftentimes, judicious pruning along with an appropriate cable system can save it.</p>
<p>Cabling must be done right, because a poorly designed system is more dangerous than none. The American National Standards Institute (ANSI) A300 Support System Standards for tree cabling are not an example of big-government overreach. Quite the opposite; they are industry-written, and based on decades of research. The ANSI A300 lays out specs for things like cable, bolt and eye size, construction, and load-rating. It’s critical that a cable system be installed by a Certified Arborist who is familiar with these standards.</p>
<p>Lest you fear your maple or oak will look like a Frankentree, don’t worry: a proper cable system is inconspicuous. For a fraction of the cost of a removal, and a tiny fraction of the cost of emergency removal plus home-damage repair, most trees can get an extended lease on life through cabling. While under extreme conditions even a perfect system may fail, I’ve never seen a properly installed cable system fail. I have, on the other hand, seen many homemade or substandard ones crash.</p>
<p>For information on cabling, contact your local International Society of Arboriculture (ISA) Certified Arborist (treesaregood.org has a search-by-ZIP function). When you get a quote from a professional, ask them to show you their copy of the ANSI A300 cabling standards, and insist on proof of insurance directly from their carrier. </p>
<p>It’s an appropriate time to give thanks for strong forks, both at the table and out in the landscape.</p>
<p><br/>Paul Hetzler has been an ISA-Certified Arborist since 1996, and is a member of ISA-Ontario, the Canadian Institute of Forestry, and the Society of American Foresters. His book “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” is available on amazon.com.</p>