of forest removal on amphibian migrations: implications for habitat
and landscape connectivity
Todd1, Thomas M. Luhring1, Betsie B. Rothermel1,2,
and J. Whitfield Gibbons1
River Ecology Laboratory, Drawer E, University of Georgia, Aiken, SC
2Archbold Biological Station, PO Box 2057, Lake Placid, FL
1. Habitat loss is a leading cause of global amphibian declines.
Forest removal is a particularly significant threat because an estimated
82% of amphibians rely on forests for part of their lives.
2. Biphasic amphibians rely on suitable terrestrial habitat to support
their post-metamorphic growth and survival and also to maintain appropriate
habitat and landscape connectivity.
3. We created 4 replicate, 16-ha experimental arrays in the southeastern
USA to examine the effects of forest removal on migratory movements
of adult biphasic amphibians. Each array contained four forest-harvesting
treatments that included an unharvested control, a partially harvested
stand, a clearcut with coarse woody debris retained, and a clearcut
with coarse woody debris removed.
4. Some amphibian species emigrated from wetlands in significantly greater
numbers through forest controls compared with harvested treatments.
Also, salamanders were generally more sensitive to forest removal than
were frogs, with a significantly greater proportion of salamanders migrating
through forested habitat compared to frogs.
5. For several species, individuals were significantly more likely to
avoid clearcuts when emigrating compared to immigrating. Individuals
that emigrated into clearcut treatments were more likely to reverse
direction and return to wetlands in some species.
6. Synthesis and applications. Our study identifies one mechanism
by which forest removal shapes the abundance and distribution of amphibians
in terrestrial habitat. To promote the persistence of amphibian populations,
conservation efforts should focus on preserving forest habitat adjacent
to reproduction sites. Such measures are especially important where
forest habitat connects local populations or where it links reproduction
sites to other habitat features necessary for amphibian growth, survival,
Ambystoma, Bufo, clearcutting, forestry, habitat loss, metapopulation,
Rana, timber harvesting
B. D., T. M. Luhring, B. B. Rothermel, and J. W. Gibbons. 2009. Effects
of forest removal on amphibian migrations: implications for habitat and
landscape connectivity. Journal of Applied Ecology 46(2009): 554-561.
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