The Impact of Deer on Forests

[Peter Smallidge]

As deer hunting season approaches, or continues as the case may be for early archery season, a recent post about the contribution of hunters to others in their community via "Hunters for the Hungry" reminded me of the important contribution that deer hunting can make to the health and sustainability of our hardwood forests.

 

Recent studies have added to the depth and breadth of information regarding the negative impacts that deer have on natural (and urban incidentally) ecosystems.  A survey of foresters in NY by Cornell's Human Dimensions Research Unit reports that foresters identify deer browsing pressure as the most common threat of forest regeneration in most regions of the state.  Invasive and interfering plants also factored prominently in the list of barriers to regeneration.  Similarly, a study by The Nature Conservancy using USFS field data assessed potential barriers to regeneration.  They found that regeneration was limited in many areas, with deer as a potential factor.  I have attached a pdf copy of the report to this post, and apologize that I can't recall where I found the document on the NY TNC website.  Maybe some can share the direct link.

 

regen%20survey.NYS_TNC_Regen.2010.shirer%20and%20zimmerman.pdf

 

Picture 1.  An image of hardwood regeneration that would be nice to see more commonly. Picture by Gary Goff.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Picture 2.  Evidence of a deer problem.  This fenced exclosure in Ontario County NY shows the impact of deer on native forest vegetation.  Without the fence, it is often too easy to not see the problem because the deer consume the evidence.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Picture 3.  Deer consume approximately 7 lbs (fresh weight) of forage per day, some percentage of which may be hardwood seedlings.  If there are approximately 600 seedlings per pound, and there are 30 deer per square mile in the forest for 3 months....how many seedlings to they eat?   How many seedling do you have in your woods?

[Rich Taber]

Deer possess an inherent capacity to reproduce to very high numbers when conditions are right, and predation and other limiting factors are low.  In the absence of natural predators such as mountain lions and wolves in most settled areas, hunters bear the responsibility at keeping deer numbers to within the carrying capacity of the landscape. Deer are magnificent animals, but there should be only so many of them in any given area. Nature provided them with this huge capacity to increase their numbers, which they often historically did in areas of earlier successional habitat, provided by periodic burning of vegetation by Native Americans, abandoned beaver meadows, and river floodplains.  In areas such as NY State's Southern Tier, deer numbers can easily get very high, and have negative effects on agriculture, forest regeneration, and health and safety issues if not maintained at appropriate levels.