HR: 1330h
AN: B33E-01 [Abstracts]
TI: Physical and Biological Interactions of Intact Watersheds: Are they relevant?
AU: * Bryant, M
EM: mdbryant@fs.fed.us
AF: U.S. Forest Service, PNW Research Station, 2770 Sherwood Ln 2A, Juneau, AK 99801 United States
AB:
Intact watersheds are rare or absent throughout most of the northern hemisphere. Southeast Alaska is an exception with many
forested watersheds that either have not been or are lightly disturbed by human activity. The Kadashan River, a short (less
than 20 km) river in an old growth watershed on Chichagof Island is one example of an intact watershed. Natural processes
from the headwaters to the ocean interact to create a salmon rich environment. Steep headwater streams are sources for
sediment recruitment, nutrients (organic material and invertebrates), and large wood. Large riparian trees entering the
stream provide long term storage of sediment, create pools, and link the main stream to off-channel habitats. A natural
discharge regime that floods a complex riparian zone with abundant beaver ponds is a key process that maintains this complex
system. Examples of these processes and salmonid populations in the Kadashan River illustrate how they interact to support
one of the more productive watersheds in southeast Alaska. Understanding and quantifying processes in intact watersheds
provide an opportunity to test major river paradigms and provide reference points for watershed restoration projects
elsewhere.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2005 Joint Assembly