Response of Forest Floor Vertebrates to Riparian Hardwood Conversion Along the Bear River, Southwest Washington
Author: MacCracken J.G.1
Source: Forest Science, Volume 48, Number 2, 1 May 2002 , pp. 299-308(10)
Abstract:
The conversion of riparian red alder (Alnus rubra) forest to conifers for salmon (Oncorhynchus spp.) habitat improvement is controversial. I monitored changes in vegetation, microclimate, and the abundance, distribution, and body condition of small mammals and amphibians during the initial stage of alder conversion. Treatments reduced alder and moss cover [mean standardized effect size (ES) = -2.38 and -1.23, respectively (P = 0.0001)], but increased shrub and forb cover [ES = 0.98 and 0.37, respectively (P = 0.0001)]. Treatment effects on microclimate were neutral to moderate (ES = 0.00 to 0.67, P = 0.2). Effects on pitfall trap capture rates of small mammals were small to moderate (ES = -0.04 to 0.51, P = 0.2) and varied by taxon, and effects on captures of amphibians were small (P = 0.2), but positive (ES = 0.05 to 0.26). Pitfall captures were influenced more by seasonal weather patterns than treatment effects on vegetation. Differences in the density of torrent salamanders (Rhyacotriton kezeri) in streams in conversion and control sites were large (ES = -1.00, P = 0.4) and moderate for giant salamanders [ Dicamptodon spp. (ES = 0.31, P = 0.4)]. Treatment effects on the mass/individual for three species of shrew were small (P = 0.2 to 0.9) and either negative or neutral (ES = -0.21 to 0.00) for juveniles and adults. Effects on the mass of western red-backed salamanders (Plethodon vehiculum) were small for adults (ES = -0.12, P = 0.6) and juveniles (ES = 0.08, P = 0.8). Treatment effect on the mass of red-legged frogs (Rana aurora) was positive ( P = 0.2) for both age classes (adult ES = 0.52, juvenile ES = 0.20). The effect of conversion on the mass of torrent salamanders was positive (adult ES = 1.00, P = 0.002; juvenile ES = 0.25, P = 0.02). Additional research should focus on confirming my results, longer term effects, and additional wildlife species. FOR. SCI. 48(2):299–308.Keywords: Community ecology; disturbance ecology; habitat change; riparian management; environmental management; forest; forest management; forest resources; forestry; forestry research; forestry science; natural resources; natural resource management
Document Type: Miscellaneous
Affiliations: 1: Wildlife Biologist Timber Department, Longview Fibre Company, 300 Fibre Way, Longview, WA, 98632, Phone: (360)575-5109; Fax: (360)575-5932 jmac@longfibre.com
