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An analysis of conifer seedling morphology as influenced by two different silvicultural systems

University of British Columbia

The growth responses of Pseudotsuga menziesii (Mirb.) Franco and Abies grandis (Dougl.) Lindl. seedlings planted near Squamish, British Columbia in the CWHdm biogeoclimatic zone were examined in order to describe the general growth patterns expressed and their relationships to light, temperature and soil moisture levels in two different forest environments, a small clearcut or clearing and a shelterwood. Seedling growth patterns and general morphology were analyzed using a combination of multivariate and univariate statistics. Each revealed consistent spatial relationships between the measured plant parts which helped describe the overall morphology of the seedlings. The best descriptors of the seedlings were found to be the current height increment, the subtending lateral branches of the apical whorl and the buds produced along the current height increment. It was also demonstrated that while different morphologies were present among both seedling species (in terms of the presence or absence of proleptic free growth) the manner in which the plant parts were integrated to form the whole seedling was often the same. The analyses of growth responses in relation to specific environmental variables resulted in the clear demonstration of site preference between each species. Grand fir seedlings grew best in the more shaded environment of the shelterwood, while Douglas fir grew best in the more open environment of the clearing. Seedlings of Douglas fir with proleptic free growth did not share this same response, however, and performed better in the shelterwood. Results generated from these analyses are presented and discussed in relation to the current understanding of conifer growth patterns, as well as the general performance of Douglas fir and grand fir seedlings in the context of reforestation.

Thesis/Dissertation

application/pdf

2009-03-26

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http://hdl.handle.net/2429/6577

Botany

University of British Columbia

UBCV

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