Record Details
Field | Value |
---|---|
Title | Synecological features of a natural headland prairie on the Oregon coast |
Names |
Davidson, Eric Duncan
(creator) Chilcote, William W. (advisor) |
Date Issued | 1966-12-09 (iso8601) |
Note | Graduation date: 1967 |
Abstract | The study of the vegetation of one of the natural coastal prairies in Oregon was undertaken for the purpose of describing some of its synecological features. Specific objectives of the study were to describe certain plant assemblages in the study area, present phenological relationships on some of the assemblages, and discuss and illustrate some examples of evidence of succession on the study area. The study area is a prairie located on a headland about one mile north of the Tillamook-Lincoln county line (Sec. 3 in T6S, R11W). This prairie is one of the many situated on the headland bluffs and slopes along the northern Pacific coast. During an initial period of reconnaissance, familiarization with the plant species and communities in the study area was gained. Several surveys along most of the Oregon coast were made to compare the study area with other coastal prairies. A total of 38 distinctive stands of vegetation within the prairie were sampled in a series of five repetitive sessions from January to October in 1966. Presence and vegetative cover of species were recorded. In addition, soil depths in these stands were recorded. Seven transects from the prairie through the ecotone to the forest were established and the presence of species along them was recorded. With the aid of an association table five distinctive communities were differentiated in the sampled stands. These were: 1. Equisetum maximum community, restricted to sites with high soil moisture during the entire year. 2. Polystichum munitum-Rubus parviflorus community, usually on soils 18 inches deep or less. Species in this community form the major part of the ecotone vegetation. 3. Carex obnupta community, usually on soils 12 inches deep or less. Carex is the only important species in this community. 4. Artemisia suksdorfii-Solidago canadensis community, found on the exposed, south-facing end of the prairie on deep soils. It is a community found commonly in prairies farther north on the coast. 5. Solidago canadensis community, situated farther up in the prairie than the Artemisia-Solidago community, on deep soils. It was judged to be an earlier successional stage of the Artemisia-Solidago community. Two more groups were apparent in the table, but these were judged not to be distinct communities in the field. These were: 6. Lupinus littoralis group, considered part of the internal pattern of one or more of the large grassy communities not sampled. The peculiar grouping of Lupinus littoralis is attributed to the large, heavy seeds of that species which always drop directly to the ground, rather than being distributed farther by the wind. 7. Angelica lucida-Rubus spectabilis group, judged to be an aberrant form of the Polystichum-Rubus parviflorus community. A discussion of successional aspects of this and other coastal prairies on the Pacific coast was based on the results of field work carried out during this study, a knowledge of activities on this prairie from 1916 to the present time, and on historical accounts and old photographs concerning the coastal vegetation. It was tentatively concluded that the coastal prairies were maintained for long periods in the past mostly by fires set by the coastal Indians who lived on them. When the white settlers arrived with their cattle and sheep, many prairies, including the study area, were maintained by grazing pressure, and the spread of hardy introduced grasses was encouraged. The stands sampled in the study area were thought to have become established during a period of no stock grazing from 1938 to the present time. It was suggested that the Polystichum munitum-Rubus parviflorus community may provide sites for the growth of Picea sitchensis within this prairie. |
Genre | Thesis/Dissertation |
Topic | Coasts -- Oregon |
Identifier | http://hdl.handle.net/1957/49053 |