Pacific Southwest Research Station

Pacific Southwest
Research Station
800 Buchanan Street
Albany, CA 94710-0011
(510) 883-8830

Research Topics Wildlife & Fish

Plethodontid Salamanders in Forest Ecosystems of the Pacific Northwest: Are They Good Metrics for Ecosystem Integrity?

Forest salamanders of the family Plethodontidae do not require standing water for breeding or other life functions, relying instead on moist substrates in upland forest habitats where they forage, mate, and lay and guard their eggs.

Salamanders can comprise more biomass in forested habitats than all other small vertebrate species combined. Eighty-three percent of the amphibian and reptile species found in one study were salamanders, most of them members of the family Plethodontidae.

Species in the family are lungless, absorbing oxygen directly through their moist skins. This biophysical limitation means that they require a cool, moist microclimate for respiration and to avoid desiccation. They tend to occupy, and reach their highest densities, in forests with abundant decaying logs, deep, moist humus, and other cool, moist microhabitat conditions characteristic of late-seral forests.

As a consequence of their physiological limitations, forest Plethodontid salamander populations are sensitive to modifications of forest structure that, when altered, can change the forest microclimates.

Arguably, many of these same components of the forest environment create and maintain habitat conditions required by a majority of forest-adapted biota.

Given their typically high relative abundance, ease of sampling, and the direct links between their numbers and key structural attributes of the forest that support other elements of the forest biota, Plethodontid salamander diversity and abundance may be optimal metrics of forest ecosystem integrity.