Effects of forest management practices on treefrog oviposition site choice

Abstract only availableGlobally, amphibian populations are declining faster than those of birds or mammals. Habitat destruction is considered the primary cause of these declines; however, what remains partly unexplored is the idea that some species may be more greatly affected than others by deforestation. Treefrogs (Family: Hylidae), because of their mobility, may be expected to circumvent disturbed habitats; however, because of their dependency on arboreal habitat, they may be adversely affected by different forms of forest management. As part of the LEAP (Land-Use Effects on Amphibian Populations) study, four forest management practices—clearcut with coarse woody debris (CWD) removed, clearcut with CWD retained, thinning of 25% basal area, and uncut forest—were implemented at four wetlands at the Savannah River Site. In May 2005, we placed wading pools 25 m into each treatment and allowed them to fill with rainwater. To monitor time to first oviposition event and to determine the number of events per treatment, pools were checked daily, eggs were counted, and tadpoles were raised to confirm that all eggs were indeed those of hylids. We measured water depth, canopy cover, and surrounding vegetation. These data will be analyzed to determine if suitable calling/breeding habitat (microhabitat) is a more reliable predictor of oviposition than treatment (macrohabitat). At three of the four wetlands, first oviposition events occurred in the thinning treatments, and second events occurred in the clearcuts with CWD retained. We found that more oviposition events also occurred in the thinning treatments (43%) and the clearcuts with CWD retained (33%) than in the clearcuts with CWD removed (13%) or the uncut forest controls (10%). One explanation for these findings is that hylids have evolved to locate openings in the forest canopy which could indicate a wetland or a fallen tree whose uprooting has caused an ephemeral pool to form.Life Sciences Undergraduate Research Opportunity Progra

Effects of Timber Harvest on Amphibian Populations: Understanding Mechanisms from Forest Experiments

Accompanying appendix may be accessed at: http://hdl.handle.net/10355/1365Harvesting timber is a common form of land use that has the potential to cause declines in amphibian populations. It is essential to understand the behavior and fate of individuals and the resulting consequences for vital rates (birth, death, immigration, emigration) under different forest management conditions.We report on experimental studies conducted in three regions of the United States to identify mechanisms of responses by pond-breeding amphibians to timber harvest treatments. Our studies demonstrate that life stages related to oviposition and larval performance in the aquatic stage are sometimes affected positively by clearcutting, whereas effects on juvenile and adult terrestrial stages are mostly negative

Effects of Timber Harvest on Amphibian Populations: Understanding Mechanisms from Forest Experiments. Appendix

Appendix only of an article to be published in BioScience by the American Institute of Biological Sciences.The Appendix provides a summary of results for four forest management treatments according to region, species, and response variables