Environment and Ecology Research Vol. 4(3), pp. 169 - 174
DOI: 10.13189/eer.2016.040309
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Natural and Anthropogenic Disturbance Influences on Aquatic Biological Diversity in the Pacific Northwest

Robert J. Danehy ^1,*, Andrew R. Moldenke ^2
1 National Council for Air and Stream Improvement, Inc., United States
² Department of Botany and Plant Pathology, Oregon State University, United States

ABSTRACT

Aquatic biological diversity in Pacific Northwest (PNW) forests was examined after two disturbance types: natural (flooding with and without associated debris flows); and anthropogenic (canopy removal). Within the region two multi-decade studies on aquatic insects in western Oregon establish the likely upper ends of forested stream richness, with richness values of ≈300 taxa collected at Berry Creek and 449 taxa within a small watershed (Lookout Creek, 6400 ha). Therefore, compared to intensively studied sites, at least 100 to 200 species have not been documented at these sites. We examine disturbance impacts on assemblage richness in the PNW with data from three studies characterized by similar levels of sampling and taxonomic effort. Rare species were important contributors to richness, as 20 to 30% of taxa within each study area were found at only one site. Mature, clearcut, high flow, and debris flow disturbance states were compared. Ephemeroptera (p=<0.001) richness increased after debris flows and high flows, and Chironomidae (p=0.04) increased after debris flows and clearcutting. Site variability was high, with assemblage structure weakly clustered by disturbance severity as debris flow disturbance (characterized by both streambed and canopy removal) mostly separated from high flow and clearcut disturbances.

KEYWORDS
Debris Flow, Disturbance, Flood, Forest, Harvest, Macroinvertebrates, Stream

Cite This Paper in IEEE or APA Citation Styles
(a). IEEE Format:
[1] Robert J. Danehy , Andrew R. Moldenke , "Natural and Anthropogenic Disturbance Influences on Aquatic Biological Diversity in the Pacific Northwest," Environment and Ecology Research, Vol. 4, No. 3, pp. 169 - 174, 2016. DOI: 10.13189/eer.2016.040309.

(b). APA Format:
Robert J. Danehy , Andrew R. Moldenke (2016). Natural and Anthropogenic Disturbance Influences on Aquatic Biological Diversity in the Pacific Northwest. Environment and Ecology Research, 4(3), 169 - 174. DOI: 10.13189/eer.2016.040309.