Open Collections

Plant communities and their standing crops on estuaries of the east coast of Vancouver Island

University of British Columbia

The emergent plant communities on eighteen estuaries on the east coast of Vancouver Island and one estuary on the mainland coast of British Columbia are described and their distribution mapped (scale 1 cm = 48 m, 1 cm = 158 m, 1 cm = 32 m). There are eleven types of estuaries. Monthly measurements of nitrogen (N) and standing crop by living, dead, senescent and duff portions were made on eleven communities in five estuaries; 1. Cowichan Carex lyngbyei and Juncus balticus; 2. Chemainus Salicornia virginica and Distichlis spicata - Grindelia integrifolia; 3. Little Qualicum Carex lyngbyei and Potentilla pacifica - Carex lyngbyei; 4. Campbell Carex lyngbyei and Potentilla pacifica - Eleocharjs palustris; and; 5. Salmon Carex lyngbyei, Deschampsia cespitosa - Carex lyngbyei and Poa pratensis -Agrostis alba var. stolonifera - Potentilla pacifica. Root cores collected monthly from five plots in each community were grown in the dark at 20°C to measure root reserves. Kjeldahl nitrogen (N) was determined for representative samples as a rough measure of the quantity of protoplasmic constituents as opposed to structural components. The highest N values occurred in the living portions with the highest, 2.43%, occurring in April in the Cowichan Carex lyngbyei community. The standing crops (gm m⁻²) are [See Thesis for Chart]. The largest standing crops occur in the Carex lyngbyei, and Chemainus Salicornia virginica and Distichlis spicata -Grindelia integrifolia communities. While dry matter in the Carex lyngbyei communities disappeared between the growing seasons it accumulated in the Salicornia virginica and Distichlis spicata - Grindelia integrifolia communities. Dry matter accumulated to a lesser extent in the higher elevation communities. Etiolated shoots from root cores grew in the dark from 0 to a maximum of 573 days for the Little Qualicum Potentilla pacifica - Carex lyngbyei community. Root reserves are periodic with the decreasing trend in April and May coinciding with the initiation and rapid growth of the canopy. The peak in standing crop is followed by a peak in root reserves within one month. It is proposed that some carbohydrates and mineral elements are translocated, and reallocated between the below and above ground structures.

Text

2010-04-13

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/23398

Plant Science

University of British Columbia

Graduate