- Babbitt, Kimberly J.
University of New Hampshire, Durham
Forest ecosystem management presents an enormous challenge that requires the use of novel approaches in land stewardship. The central problem is finding the best way to manage forests for timber products, while protecting and maintaining the ecological health of the forest. The protection of vernal pools from timber harvesting is largely dependent on recently developed Best Management Practices (BMPs) that advocate the delineation of terrestrial buffer zones around these habitats to protect amphibians (and other wildlife). However, empirical data on the response of amphibians to buffer management is lacking. To address this question we are examined the effects of terrestrial buffer zone management on amphibian movement and demographics though a landscape-scale field experiment where we manipulated buffer wide by surrounding intact forest with clearcuts. We encircled vernal pools with drift fences and pitfall traps and captured amphibians entering and exiting. We also use radiotracking to track wood frog and spotted salamander movement. Demographic responses were highly variable but body condition of amphibians at wetlands with the smallest (30 m) buffers was lower than from sites with no cutting. Amphibians entered and left wetlands in non-random but variable directions across years and among species suggesting that corridor approaches to management may not be best in this managed landscape. Wood frogs and spotted salamanders moved up to 428 m and 350 m from breeding ponds, respectively. Wood frogs crossed but did not use clearcuts as summer/fall habitat. Salamanders only crossed cuts during a wet year and used mammal burrows extensively, even in clearcuts. There was no evidence that the treatments we examined will result in local population loss, but whether this indicates that a 30-m wide buffer is sufficient is still unclear. However, given the data on body condition it seems unlikely that smaller buffers would be adequate. 100-m wide clearcuts appear permeable to movement and the response of amphibians to buffer treatment are partly due to the width of the cuts. Research on response to wider cuts would be necessary to fully understand the connection between upland habitat and population viability. Overall our results suggest that productive forest management and protection of vernal-pool dependent amphibians can be accomplished but more empirical study on effects of buffer management are needed to assess long term population responses.