Record Details
The seasonal occurrence and distribution of stoneflies (Plecoptera) of a western Oregon stream
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The seasonal occurrence and distribution of stoneflies (Plecoptera) of a western Oregon stream |
| Names |
Kerst, Cary Dean
(creator) Anderson, N. H. (advisor) |
| Date Issued | 1969-11-26 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Plecoptera were collected from four sampling stations selected to represent a range of conditions on Oak Creek, a small woodland stream originating in the foothills of the Oregon Coast Range. The elevation of Site I was 700 ft. while the lowest site was located at 225 ft. Monthly benthos samples were taken for one year from a riffle and glide section at each site using a stovepipe sampler (6 in. dia. ) and a standard tropical fish net. Samples were sorted in the laboratory and Plecoptera identified and placed into 1 mm size classes. Emergence of adults was measured for 13 months using a tent-shaped trap (1 m²) at each site. Traps were checked once or twice weekly. Forty-two species of Plecoptera were found in Oak Creek. The number of species is very large when compared with other studies. The stonefly fauna is fairly similar to that reported 35 years ago. Thirty-seven of the 42 species complete emergence during the spring. Temporal separation is marked in the emergence periods of Nemoura and Leuctra. Examples of split emergence periods and early emergence of males were found. Life cycle information is given for a number of species and genera. Using the Shannon-Wiener function, diversity of emerging adults ranks by season as: Spring > Summer > Winter > Fall. The diversity of the sites on a yearly basis is: II > I > III > IV. Using a percentage of similarity index it is concluded that Sites I and II are very similar. Site III is intermediate while Site IV is quite different. A number of examples of restricted distributions are cited. These examples illustrate that differences in longitudinal distribution are important in ecological segregation. Herbivorous stoneflies (suborder Filipalpia) comprise a greater proportion of the fauna at the upper site while predaceous stoneflies (Setipalpia) predominate in the lower areas. Water depth and amounts of leaves and silt are important factors in determining the distribution of stoneflies. Most species are abundant in leaf drifts. Microhabitat selection does not appear to be rigorous. |
| Genre | Thesis/Dissertation |
| Topic | Stoneflies |
| Identifier | http://hdl.handle.net/1957/46237 |
