Life history predicts recovery rate from past land use in southern Appalachian salamanders

Background/Question/Methods

Forest management often represents a balance between complex social, economic, and ecological objectives. Sustainable management of forest-dependent species relies on understanding how the timing, intensity, and spatial pattern of timber harvest influence ecological communities over the long-term.  In the eastern United States, numerous studies have established that terrestrial salamander populations initially decline in abundance following timber harvest, yet the large-scale and long-term consequences are relatively unknown. In the summer of 2012, we conducted 5 repeated surveys of 136 terrestrial survey points which spanned a forested landscape which has been historically managed for timber production. We used binomial mixture models to examine the relationship between salamander abundance and historic timber harvest while accounting for imperfect detection of individuals.

Results/Conclusions

Overall, stream- and terrestrial-breeding salamanders appeared to differ by magnitude of population decline and rate of population recovery. Specifically, we found that the estimated abundance of both species groups was positively associated with stand age, with recovery rates predicted to increase over time for our terrestrial species while decreasing in our stream-breeding species. Abundance of stream-breeding salamanders was predicted to reach a peak by 100 years post-harvest, while population growth of terrestrial salamanders was predicted to undergo a significant acceleration at 100 years. Estimated abundance of stream-breeding salamanders was also negatively associated with the distance to adjacent forest in young timber stands, suggesting the role of immigration in the recovery of these species. Our results indicate that although salamander abundance in young forest stands may be only modestly lower than in more mature forest, full recovery from timber harvest may take a substantial amount of time and may depend on species life history.