Intra-and interspecific competitions of Taxus yunnanensis population in Jinsha River Basin of northwest Yunnan Province, Southwest China
Based on the investigations of 45 objective trees and 205 competitive trees of Taxus yunnanensis population in the Jinsha River Basin of northwest Yunnan Province and by using He-gyi' s single-tree competition index model, this paper analyzed the intra- and interspecific compe-tition intensities of endangered plant T. yunnanensis. The intraspecific competition intensity of T. yunnanensis decreased with its increasing diameter at breast height (DBH) , presenting a par-tial peak curve, whereas the intraspecific competition intensity of T. yunnanensis was the highest at its DBH 5-10 cm, and then showed a decreasing trend with the increase of the DBH. The in-terspecific competition intensity (133.61) of T. yunnanensis was significantly higher than the in-traspecific competition intensity (76. 88), indicating that the competitive stress of the T. yun-nanensis population was mainly come from interspecific competition. The intra- and interspecific competition intensities of T. yunnanensis were larger than those of the local common tree species Tsuga forrestii, Betula albo-sinensis, Populus szechuanica, Quercus aquifolioides, and Aralia thomsonii var. glabrescens, with the competition indices being >5. The competition index of T. yunnanensis with the objective trees in the whole forest stand was significantly negatively correla-ted with the DBH of the objective trees, and nearly conformed to power function (CI=aDb). The larger the DBH of the objective trees, the smaller the competitive stress of the T. yunnanensis population.
国家科技期刊平台
NSTL
万方数据
维普
