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Energetics of surface‐active terrestrial salamanders in experimentally harvested forest
Author(s) -
Homyack Jessica A.,
Haas Carola A.,
Hopkins William A.
Publication year - 2011
Publication title -
the journal of wildlife management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.94
H-Index - 111
eISSN - 1937-2817
pISSN - 0022-541X
DOI - 10.1002/jwmg.175
Subject(s) - ectotherm , salamander , energetics , ecology , biology , amphibian , energy budget , predation , foraging , canopy , habitat , invertebrate , population , abundance (ecology) , environmental science , demography , sociology
Environmental temperatures affect nearly all aspects of ectotherm physiology, including terrestrial salamanders. Therefore, habitat disturbances that alter temperature regimes may interact with physiological processes to affect energy budgets of salamanders or constrain surface activity and possibly lead to changes in population‐level parameters. We hypothesized that warmer surface temperatures following harvesting of canopy trees could cause surface‐active salamanders to expend more energy for metabolism, potentially leaving a smaller proportion of the energy budget available for reproduction or storage. From 2006 to 2008, we quantified temperature regimes of salamander refugia in a field experiment replicated at 4 sites that included plots subjected to a timber harvest and plots not manipulated during this time period. At each site, we quantified temperature regimes in regenerating forest stands which, approximately 10 years earlier, experienced a range of harvest intensity from shelterwood to silvicultural clearcut. Further, we compared energetic parameters including 1) calories required to maintain homeostasis across an active season, 2) abundance of available potential energy (i.e., invertebrate prey), and 3) a measure of growth and storage (i.e., body condition index) among silvicultural treatments for surface‐active salamanders. For surface‐active eastern red‐backed salamanders ( Plethodon cinereus ), mean calories required for maintenance were approximately 33% greater in recently harvested forest compared to unharvested controls, but body condition was inconsistent among treatments, and invertebrate abundances were similar among treatments but differed by study site. In contrast, we did not detect a treatment effect in any energetic metric 8–14 growing seasons after harvesting. Given that surface‐active salamanders in recently harvested forest may be forced to restrain behaviors associated with foraging and mating or trade‐off growth or reproduction for increased basic maintenance costs, energetics may be an important but overlooked short‐term contributor to observed changes in abundances, reproductive demography, or surface activities after timber harvesting. Managing for both the rapid recovery of understory vegetation and retention of large stumps and logs may help mitigate warming of microclimate for salamanders and should be considered further. © The Wildlife Society, 2011