Interspecific association of different communities in Taxus cuspidata Sieb. et Zucc. habitat

This study investigated the concentrated distribution area of Taxus cuspidata Sieb.et Zucc. in Duhuangzi forest farm, Wangqing County, Jilin Province, China. Based on variance ratio (VR), Ochiai index (OI), and Spearman rank correlation coefficients, the interspecific associations of three communities were analyzed, including spruce-fir forest (community 1), spruce-fir forest (community 2), and birch forest (community 3). Results showed that the VR values of the three communities were all less than 1, and the main species in community 3 showed a significant negative correlation, while the other two communities showed no significant negative correlation. Based on OI, the species with high correlation (0.6 < OI ≤ 1) in communities 1 and 2 accounted for a higher proportion than that in community 3. Average OI between T.cuspidata and major tree species decreased from community 1 to 3. Based on Spearman rank correlation coefficients, most species showed no significant correlation. Only the positive and negative correlation ratio of community 1 was greater than 1. The overall association between species in the spruce-fir forest was relatively close and stability was high, while the situation in the birch forest showed the opposite pattern.