Riparian Management and the Tailed Frog in Northern Coastal Forests
Forest Ecology and Management 124 (1999) 35±43 Riparian management and the tailed frog in northern coastal forests Linda Dupuis*,1, Doug Steventon Centre for Applied Conservation Biology, Department of Forest Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z4 Ministry of Forests, Prince Rupert Region, Bag 5000, Smithers, BC, Canada V0J 2N0 Received 28 July 1998; accepted 19 January 1999 Abstract Although the importance of aquatic environments and adjacent riparian habitats for ®sh have been recognized by forest managers, headwater creeks have received little attention. The tailed frog, Ascaphus truei, inhabits permanent headwaters, and several US studies suggest that its populations decline following clear-cut logging practices. In British Columbia, this species is considered to be at risk because little is known of its abundance, distribution patterns in the landscape, and habitat needs. We characterized nine logged, buffered and old-growth creeks in each of six watersheds (n 54). Tadpole densities were obtained by area-constrained searches. Despite large natural variation in population size, densities decreased with increasing levels of ®ne sediment (<64 mm diameter), rubble, detritus and wood, and increased with bank width. The parameters that were correlated with lower tadpole densities were found at higher levels in clear-cut creeks than in creeks of other stand types. Tadpole densities were signi®cantly lower in logged streams than in buffered and old-growth creeks; thus, forested buffers along streams appear to maintain natural channel conditions. To prevent direct physical damage and sedimentation of channel beds, we suggest that buffers be retained along permanent headwater creeks. Creeks that display characteristics favoring higher tadpole densities, such as those that have coarse, stable substrates, should have management priority over less favorable creeks.
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