UBC Theses and Dissertations
Primary production of the Fraser River delta foreshore : yield estimates of emergent vegetation Yamanaka, Koji
The emergent vegetation of tidal marshes of the Fraser River foreshore is probably of great importance to the rich life of the foreshore, especially to waterfowl and fish. The vegetation "fixes" solar radiation which is "released" as organic matter in the brackish marsh and salt water marsh ecosystems. Much of the foreshore vegetation, however, has been destroyed by diking and industrial development and more destruction from many sources is threatened. My study was initiated to assay present standing crops of emergent vegetation in the major areas from Point Grey to the International Boundary and also to establish semi-permanent transects for the study of future vegetation change. Fourteen semi-permanent transects, the combined length of which is 7,550 meters (4.7 miles), were established from shore seawards at points in the area from Point Grey to Crescent Beach, roughly a distance of 30 kilometers (19 miles). Both plant and soil samples were collected along the transects, at intervals, in 1973 and 1974; dry matter yield, ash, nitrogen and lignin were determined for plant samples; pH, organic matter and electric conductivity were determined on soil samples. The standing crop of the tidal marshes, estimated to occupy 1,901 hectares (4,697 acres) was approximately 9,408 metric tons of dry matter with an average d.m. yield of 4.9 tons per hectare (4,400 lb./acre). Eight marsh plants contributed overwhelmingly to the d.m. yield: Carex lyngbyei, Soirpus conericanus and Soirpus paludosus alone accounted for 81% of the standing crop in 1974.
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