An analysis of interspecific associations of Pinus squamata with other dominant woody species in community succession

Pinus squamata is an extremely endangered pine from northeast Yunnan Province of China, which was reported from only one locality where there are 32 individuals in the field. In order to analyze its ecological relationships with other trees and shrubs, a series of techniques, including analysis of variance, χ2 test and percentage of co-occurrence, were used to analyze interspecific associations of dominant woody species in communities with P. squamata. The results indicated significantly positive correlation of the association of overall woody species in the two communities with P. squamata. There is also significantly positive correlation in the community on the north facing slope, but only a positive correlation in the community on the south-west facing slope. Considering that the community on the south-west facing slope is mixed coniferous and broad-leaved forest and that on the north facing slope is evergreen broad-leaved forest, the results imply that the communities with P. squamata may be in succession from mixed coniferous and broad-leaved forest to evergreen broad-leaved forest. Combined with the data of χ2 test and percentage of co-occurrence, we conclude that P. squamata has no significant correlation with other woody species, and its co-occurrence with other trees may be by chance. Finally, its requirements for survival may be threatened by evergreen broad-leaved woody species.