There has been much debate in the popular press lately regarding the role of timber harvesting on forest communities. A common focus of this debate is the perceived impacts to wildlife. Most believe that leaving our forests alone is best for wildlife. However, to provide habitat for all of our native forest wildlife species, forests need to be diverse in terms of age, species and area. Harvesting timber is the primary means of achieving this structural diversity. The purpose of this article is to summarize some key points regarding the effects of harvesting on reptiles and amphibians. These points are drawn mostly from the Hardwood Ecosystem Experiment (HEE), an ongoing research study in southern Indiana. Its primary focus is to study forest management and its effects on plants and animals. A more detailed summary may be found in Forest Management for Reptiles and Amphibians.
There has been several large-scale studies that have investigated the effects of tree canopy removal on amphibians and reptiles. These include the HEE in Indiana, the Missouri Ozark Forest Ecosystem Project (MOFEP), and the Land-use Effects on Amphibian Populations (LEAP). Much of the work from these projects has been published in the scientific literature. All of these studies demonstrate that the response of amphibians and reptiles to timber harvesting is variable—it cannot simply be quantified as good or bad. Indeed, avoiding negative impacts to all reptiles and amphibians as a result of timber harvesting is neither possible nor desirable since disturbance-dependent wildlife species1,2 and many mature forest species3, require early successional forests.
For the focal species studied on the HEE, most exhibited moderate or no response in 1-3 years following timber harvests. The focal species I and colleagues have studied were timber rattlesnakes (Crotalus horridus), eastern box turtles (Terrapene carolina), and terrestrial salamanders. Timber harvests had no effect on the area male or female adult timber rattlesnakes used during the active season. There was no evidence that snakes changed movement behaviors to avoid clearcuts4. Indeed, several snakes were observed within clearcuts for several weeks and across multiple years. Annual survival of rattlesnakes on the HEE sites was high during the active season (72-98%) and winter (97-99%). Timber harvesting had no impact on survival. Declines in female survival was most affected by declines in prey abundance the previous year which were due to tree mast failures5. The level of acorns and nuts (i.e., mast) produced in woodlands naturally vary from year to year. When the small mammal population declined due to mast failure, these snakes were apparently impacted the following year.
For full blog view: Harvesting Our Forests - The Wildlife Debate, Purdue Extension-Forestry and Natural Resources Blog.
Wildlife Responses to Timber Harvesting, Video-The Education Store-Purdue Extension Resource Center
Hardwood Ecosystem Experiment – Forest Birds, Video-The Education Store
Managing Woodlands for Birds, Video-The Education Store
Sustaining Our Oak-Hickory Forests, Video-The Education Store
Breeding Birds and Forest Management: the Hardwood Ecosystem Experiment and the Central Hardwoods Region, The Education Store
Forest Management for Reptiles and Amphibians: A Technical Guide for the Midwest, The Education Store
Addressing Concerns About Management of Indiana’s Forests, Department of Forestry and Natural Resources, Purdue University
Hardwood Ecosystem Experiment (HEE)
Brian MacGowan, Extension Wildlife Specialist
Department of Forestry & Natural Resources, Purdue University
1 Thompson, F. R., III, and D. R Dessecker. 1997. Management of early-successional communities in central hardwood forests: with special emphasis on the ecology and management of oaks, ruffed grouse, and forest songbirds. U.S. Forest Service General Technical Report NC-195, St. Paul, MN, USA.
2 Greenberg, C. H., B. Collins, F. R. Thompson, III, and McNab, W. H. 2011. “What are early successional habitats, why are they important, and how can they be sustained?” Pages 1-10 in Sustaining young forest communities: ecology and management of early successional habitats in the Central Hardwood Region, USA. C. H. Greenberg, B. Collins, and F. R. Thompson, III., editors. Springer, New York, NY, USA.
3 Chandler, C. C., D. I. King, and R. B. Chandler. 2012. Do mature birds prefer early-successional habitat during the post-fledging period? Forest Ecology and Management 264:1-9.
4 MacGowan, B.J., Currylow, A.F.T., and MacNeil, J.E. 2017. Short-term responses of Timber Rattlesnakes (Crotalus horridus) to even-aged timber harvests in Indiana. Forest Ecology and Management 387(1):30-36.
5 Olson, Z.H., B.J. MacGowan, M.T. Hamilton, A.F.T. Currylow, and R.N. Williams. 2015. Survival of timber rattlesnakes: Investigating individual, environmental, and ecological effects. Herpetologica 71:274-279.