Study on the Intraspecific and Interspecific Competition of Pseudolarix amabilis in Changxing County, Zhejiang Province

Pseudolarix amabilis (Nelson) Rehd. is a rare and endangered plant endemic to China that has played a vital role in the study of Pinaceae phylogeny. Because of the serious effects of external factors, the wild populations are gradually decreasing. To illustrate the competition in the P. amabilis community, the intra- and interspecific competition of P. amabilis in Changxing County, Zhejiang Province, were investigated based on the Hegyi individual competition index (CI) model. The relationships between 21 target trees and 454 competitor trees within the P. amabilis community were analysed by using the competition intensity. The results indicated that competitive stress to the P. amabilis population mainly came from interspecific competition, which accounted for approximately 70% of the total. The intensity of interspecific competition with P. amabilis followed the order of P. amabilis>Phyllostachys edulis>Castanea mollissima>Quercus chenii>Rhus chinensis>Acer davidii>Ilex chinensis> Platycarya strobilacea> Lindera glauca> Castanopsis sclerophylla. The value of the competition index decreased with increasing distance. The CI of P. amabilis with the target trees in the whole forest stand was significantly negatively correlated with the DBH of the target trees and followed the power function (CI = AD(-B)). In terms of the competition model, effective artificial measures should be implemented to improve the survival of P. amabilis, which could help restore the wild population.