Log and soil temperature profiles in managed headwater sub-basins in the Oregon coast range: implications for wildlife habitat

Abstract

Down wood provides important faunal microhabitat in forests for many invertebrate taxa, small mammals, and amphibians. Habitat suitability of down wood as refugia is an increasing concern in managed forests of the US Pacifi c Northwest, where overstory reduction may result in both reduced down wood recruitment and increased temperatures within logs, which may make them unsuitable habitat refugia. We examined temperature regimes inside logs and soils to assess buff ering capabilities against summer temperature extremes and potential habitat suitability for plethodontid salamanders. Temperature profi les of small- (0.3–0.45 m) and large- (0.7–1.0 m) diameter logs, as well as ambient soil and air temperatures, were measured in a 60-year-old forest stand under diff erent slope positions (0–5 m and 35–40 m from stream edge) in three case studies: 1) along a headwater stream with a narrow riparian buff er (~6 m) and moderate upland thinning; 2) along a headwater stream with a wider riparian buff er (~15 m) and moderate upland thinning; and 3) along a headwater stream with an unthinned upland. Streamside and upslope maximum air temperatures experienced on all three streams during our study were near to or exceeded critical temperatures for western plethodontid salamanders (i.e., ~30°C). Streamside and upslope temperatures inside small logs, large logs, and soils stayed below critical temperatures. Our results suggest that logs of a wide size range as well as soils may provide suffi cient protection against thermal extremes in uncut forests and thinned stands with limited overstory.

Parent Publication

• Density management in the 21st century: west side story

Citation

Kluber, Matthew R.; Olson, Deanna H.; Puettmann, Klaus J. 2013. Log and soil temperature profiles in managed headwater sub-basins in the Oregon coast range: implications for wildlife habitat. In: Anderson, P.D.; Ronnenberg, K.L., eds. Density management in the 21st century: west side story. Gen. Tech. Rep. PNW-GTR-880. Portland, OR: US Department of Agriculture, Forest Service, Pacific Northwest Research Station: 214-214.