Forest restoration efforts commonly employ silvicultural methods that alter light and competition to influence species composition. Changes to forest structure and microclimate may adversely affect some taxa (e.g., terrestrial salamanders), but positively affect others (e.g., early successional birds). Salamanders are cited as indicators of ecosystem health because of their sensitivity to forest floor microclimate. We used drift fences with pitfall and funnel traps in a replicated Before-After-Control-Impact design to experimentally assess herpetofaunal community response to initial application of three silvicultural methods proposed to promote oak regeneration: prescribed burning; midstory herbicide; and shelterwood harvests (initial treatment of the shelterwood-burn method) and controls, before and for five years post-treatment. Species richness of all herpetofauna, amphibians, reptiles, frogs, salamanders, or snakes was unaffected by any treatment, but lizard species richness increased in the shelterwood harvest. Capture rate of total salamanders decreased post-harvest in shelterwood units after a 2-3 year delay; Plethodon teyahalee decreased post-harvest in shelterwoods, but also in control units. In contrast, capture rate of total lizards and Plestiodon fasciatus increased in shelterwood stands within the first year post-harvest. Prescribed burn and midstory herbicide treatments did not affect any reptile or amphibian species. A marginally lower proportion of juvenile to adult P. teyahalee, and a higher proportion of juvenile P. fasciatus in shelterwood than control units suggested that heavy canopy removal and associated change in microclimate may differentially affect reproductive success among species. Our study illustrates the importance of longer-term studies to detect potential changes in herpetofaunal communities that may not be immediately apparent after disturbances, and highlights the importance of including multiple taxa for a balanced perspective when weighing impacts of forest management activities.
Salamanders are an important ecological component of eastern hardwood forests and may be aff ected by natural or silvicultural disturbances that alter habitat structure and associated microclimate. From May to August in 2008 (pretreatment) and 2011 (post-treatment), we evaluated the response of salamanders to three silvicultural practices designed to promote oak regeneration -prescribed fi re, midstory herbicide application and shelterwood harvest -and a control. We trapped salamanders using drift fences with pitfall traps in fi ve replicates of the four treatments. Only the southern gray-cheeked salamander Plethodon metcalfi and the southern Appalachian salamander P. teyahalee were captured in suffi cient numbers for robust statistical analysis. We analyzed data for these species using single-species dynamic occupancy models in statistical software program R. We allowed changes in four covariates to infl uence extinction probability from pre-to post-treatment implementation: 1) percent leaf litter cover; 2) percent understory cover; 3) percent CWD cover; and 4) percent canopy cover. h e fi nal combined model set describing extinction probability contained four models with Δ AIC Ͻ 2 for P. metcalfi and nine models with Δ AIC Ͻ 2, including the null model, for P. teyahalee . For both species, the 95% confi dence intervals for model-averaged extinction probability parameter estimates overlapped zero, suggesting none were signifi cant predictors of extinction probability. Absence of short-term salamander response in midstory herbicide and prescribed burn treatments was likely because of minor or transitory changes to forest structure. In shelterwood harvests, any potential eff ects of reduced canopy and leaf litter cover may have been mitigated by rapid post-treatment vegetation sprouting. Additionally, climatic conditions associated with high elevation sites and high amounts of rainfall in 2011 may have compensated for potential changes to microclimate. Continued monitoring of Plethodon salamanders to assess responses at longer time scales (e.g. Ͼ 3 years post-treatment) is warranted.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.