Research Wildlife Biologist
1700 Bayview Drive
Arcata, CA 95521
Hartwell Welsh conducts research documenting the ecological roles of amphibians and reptiles, including their trophic relatinships, population status, and sensitivities to natural and anthropogenic perturbations; information critical to preserving these unique creatures and highlighting their importance within ecosystems and illuminating the ecological services they perform.
amphibian and reptile natural history, their population status, their sensitivity to natural and anthropogenic purturbations, and their use as biometrics of ecosystem status.
Welsh has led studies on the use of amphibians as indicators of both terrestrial and aquatic ecosystem status. Amphibians are extremely sensitive to relatively small changes in microclimate and are habitat specialists highly adapted to specific environmental features. These characteristics allow them to serve as veritable barometers of ecosystem health and status. Most recently, Welsh developed a blueprint for using amphibians in Pacific Northwest streams to monitor their potential to support ecological services, such as production of commercially valuable salmonid species.
In other studies, Welsh developed habitat models for many forest amphibians and reptiles of the Pacific Northwest. These models provide managers with a description of the habitat requirements of these species, which allow the managers to address human-caused stresses such as timber harvest and water diversions. One of Welsh's latest models was created using Forest Inventory and Analysis (FIA) data, a unique approach that was not initially envisioned within the FIA Program.
- University of California, Berkeley, Ph.D. Wildlife Ecology, 1993
- Humboldt State University, M.S. Wildlife Biology, 1976
- University of California, Berkeley, B.A. Zoology, 1972
- Society for Conservation Biology, Member
- Society for the Study of Amphibians and Reptiles, Member
- American Society of Ichthyology and Herpetology, Member
Featured Publications & Products
- Welsh, Hartwell, Jr..; Hodgson, Garth. 2010. Spatial relationships in a dendritic network: the herpetofaunal metacommunity of the Mattole River catchment of northwest California..
- Welsh, H. H., Jr..; Wheeler, C. A.; Lind, A. J. 2010. Spatial ecology of the aquatic garter snake, Thamnophis atratus, in a free-flowing stream environment.
- Fuller, Terra; Pope, Karen; Ashton, Donald ; Welsh, Hartwell, Jr. 2010. Linking the distribution of an invasive amphibian (Rana catesbeiana) to habitat conditions in a managed river system in northern California..
- Welsh, H. H. Jr.; G. R. Hodgson, J. J.; Duda, J. M. Emlen. 2010. Faunal assemblages and multi-scale habitat patterns in headwater tributaries of the South Fork Trinity River - an unregulated river embedded within a multiple-use landscape.
- Best, M. L.; Welsh, H. H., Jr. 2014. The trophic role of a forest salamander: impacts on invertebrates, leaf litter retention, and the humification process.
- Welsh Jr., Hartwell H. 2011. Frogs, fish and forestry: An integrated watershed network paradigm conserves biodiversity and ecological services.
Publications & Products
- Wheeler, Clara; Bettaso, James; Ashton, Donald; Welsh, Hartwell, Jr. 2014. Effects of water temperature on breeding phenology, growth, and metamorphosis of foothill yellow-legged frogs (Rana boylii): a case study of the regulated mainstem and unregulated tributaries of California's Trinity River.
- Wheeler, Clara; Bettaso, James; Ashton, Donald; Welsh, Hartwell, Jr. 2013. Effects of water temperature on breeding phenology, growth and timing of metamorphosis of foothill yellow-legged frogs (Rana boylii) on the mainstem and selected tributaries of California's Trinity River - 2004-2009..
- Wheeler, Clara A.; Welsh Jr., Hartwell H.; Ollivier, Lisa M. 2013. Reproductive biology of the Del Norte salamander (Plethodon elongatus)..
- Welsh, Hart; Clark, W. H.; Franco-Vizcaíno, E.; Valdéz-Villavicencio, J. H. 2010. Herpetofauna associated with palm oases across the Californian-Sonoran transition in northern Baja California, Mexico.
- Welsh, H. H., Jr..; Pope, K. L.; Wheeler, C. A. 2009. How reliable are amphibian population metrics? A response to Kroll et al..
- Welsh, H. H., Jr..; Hodgson, G. R. 2009. Stream amphibians as metrics of critical biological thresholds in the Pacific Northwest, U.S.A.: a response to Kroll et al..
- Pope, Karen L.; Garwood, Justin M.; Welsh Jr., Hartwell H.; Lawler, Sharon P. 2008. Evidence of indirect impacts of introduced trout on native amphibians via facilitation of a shared predator.
- Cooperrider, Allen; Noss, Reed F.; Welsh, Hartwell H., Jr..; Carroll, Carlos.; Zielinski, William; Olson, David; Nelson, S. Kim; Marcot, Bruce G. 2000. Terrestrial fauna of redwood forests.
- Reese, D.A.; Welsh, Hartwell H., Jr. 1997. Use of terrestrial habitat by western pond turtles (Clemmys marmorata): implications for management.
- Welsh, Hartwell H., Jr..; Wilson, R.A. 1995. Aneides ferreus (clouded salamander) reproduction.
- Welsh, Hartwell H., Jr..; Lind, A.J. 1995. Habitat correlates of the Del Norte salamander, Plethodon elongatus (Caudata: Plethodontidae) in northwestern California.
- Welsh, H.H., Jr. 1994. Bioregions: an ecological and evolutionary perspective and a proposal for California.
- Lind, A.J.; Welsh, Hartwell H., Jr. 1994. Ontogenetic changes in the foraging behavior and habitat use of the Oregon garter snake, Thamnophis atratus hydrophilus.
- Welsh, H.H., Jr. 1993. A hierarchical analysis of the niche relationships of four amphibians from forested habitats of northwestern California.
- Lind, Amy J.; Welsh, Hartwell H., Jr. 1990. Predation by Thamnophis couchii on Dicamptodon ensatus.
- Lind, Amy J.; Welsh, Hartwell H., Jr. 1990. Thamnophis ordinoides.
|Woodland Salamanders are Indicators of Redwood Forest Recovery|
Forest Service researchers have found that two common salamander species provide a way of measuring the recovery of previously harvested redwood ...