PNW 98 Session - Full Abstracts
Full Abstract
1) Contact Author: Claus R. Svendsen
2) Institution:Skagit Valley College
3) Mailing Address: 2405 East College Way, Mount Vernon, WA 98273-5899
4) Phone #:360-416-7816
5) Email: csvendse@ctc.ctc.edu
6) Presenter: Claus R. Svendsen
7) Paper or Poster: paper
8) Equipment needs other than standard slide and overhead projector:
9) Contributed session 1st choice:Restoration
10) Contributed session 2nd choice:Wildlife
11) Do you want your oral or poster presentation judged for a student award (yes or no)?: No
12) Would you like to be a judge for Student Awards (yes or no)?:No
13) Keywords:biodiversity, small mammal restoration, urban wetland
14) Authors:
CLAUS R. SVENDSEN (1)
Klaus O. Richter (2)
15) Affiliation/institution:
(1) Department of Environmental Conservation, Skagit Valley College, Mt. Vernon, WA
(2) King County Natural Resources Division, Seattle, WA
16) Abstract Title:
Small Mammals Richness in a Restored Urban Wetland in Context of Biotic and Landscape Characteristics.
17) Abstract Text:
Chase Lake wetland, located within the Puget Sound Basin of Washington, USA, is a bog that has undergone significant impacts attributable to encroachment by urbanization. To reverse this trend, a palustrine open water restoration wetland was created. This restored site with adjacent buffer was planted to augment wildlife of the entire wetland complex. To reverse this trend, the filled section was re-excavated in 1990 into a palustrine open water wetland and engineered with a downstream discharge to both capture and remove runoff with the hopes of preserving the integrity and ecological functions of the intact area (Cooke and Azous, 1995).
From autumn 1989-1995 we live trapped small mammals using pitfall and Sherman traps to document usage of the bog and recolonization of the restoration site. At the bog, the forest deer mouse was the only native species found. Exotics including the Norway and Black rats were also found. This example of poor species richness is similar to that at two other urban wetlands within the region, but significantly lower than either the 4-7 species captured in established wetlands in less developed watersheds, or the 8-13 species found in the most pristine watersheds.
From our model work, we conclude that the small mammals community at the restoration site most likely failed because of overall low small mammal diversity at the adjacent bog, the virtual isolation of both wetlands from species rich source populations, the widespread distribution of exotic small mammals, and the heavy domestic pet usage from surrounding neighborhoods.
We ruled out hydrology, water quality and vegetation characteristics as limiting factors based on our comparisons of conditions at the restoration site and 21 established wetlands. However, the model work shows that forest cover within the surrounding landscape is of high significance in maintaining small mammals. Our high correlation of small mammal richness to course woody debris across all wetlands, suggests that for restoration wetlands still connected to dispersal populations, the addition of large course woody debris may provide cover, food and other habitat requirements enabling a richer, more abundant small mammal fauna to exist.
18) Comments/Requests: