Record Details
Field | Value |
---|---|
Title | Vegetation ecology of selected mountain hemlock (Tsuga mertensiana ) communities along the eastern High Cascades, Oregon |
Names |
Schuller, S. Reid
(creator) Frenkel, Robert E. (advisor) |
Date Issued | 1977-06-01 (iso8601) |
Note | Graduation date: 1978 |
Abstract | Tree diameter, understory plant cover, seedling density, elevation, aspect, and slope steepness are recorded for 51 forest stands dominated by Tsuga mertensiana (Bong.) Carr. along the eastern portion of the central Oregon Cascades. Species dominance based on prominence values for trees and percent cover for shrubs and herbs are correlated with elevational and topographic variables. Community patterns are delineated in a two-dimensional ordination based upon similarity of composition between stands. Four provisional community types are identified along inferred length of snow free season and available soil moisture gradients: (1) Abies amabilis-Tsuga mertensiana/Vaccinium membranaceum; (2) Abies amàbilis/Vaccinium scoparium; (3) Tsuga mertensiana/Vaccinium; and (4) Tsuga mertensiana/Luzula hitchcockii. Three vegetation subzones are identified within the Tsuga mertensiana Zone based on tree size class relative frequency, seedling relative density, and species composition: (1) Subalpine subzone, where T. mertensiana dominates and is replacing itself, (2) Transition subzone, where T. mertensiana dominates and where A. amabilis development is suppressed during years of extreme snow accumulation; and (3) Montane forest subzone, where Abies arnabilis is the potential climax species but where T. mertensiana currently dominates. |
Genre | Thesis |
Topic | Mountain hemlock |
Identifier | http://hdl.handle.net/1957/9805 |