[Effects of aspect on distribution pattern of Taxus chinensis population in Yele, Sichuan Province: an analysis based on patches information].

Employing GIS method and based on patches information, this paper studied the effects of aspect on the distribution pattern of Taxus chinensis population in Yele, Sichuan Province. The results showed that Taxus chinensis population mainly distributed on the aspects of northwest, northeast, east and north. These aspect patches were absolutely dominant on area, mean size, mean edge and the number of Taxus chinensis. There existed a significant correlation between aspect and Taxus chinensis distribution. Taxus chinensis distributed preferentially on north, northeast, northwest and east patches, then on west and southwest patches, and finally on flat and southeast patches. The distribution patterns of Taxus chinensis in Yele were clustering, except on south aspect patches. The intensity of clustering on north aspect patches was the highest, with the value of Clark-Evans (CE) index being 0.906. The intensity of clustering on northeast and northwest aspect patches was lower than that on north aspect patches, with the CE value 0.797 and 0.563, respectively. The CE values on the rest aspect patches were all not larger than 0.5. There existed a significant positive correlation between the intensity of clustering index, number of patches, total patch edge, and the number of Tarus chinensis distributed on the patches, with the value of correlation coefficient 0. 936, 0.735 and 0.802, respectively. There were no significant correlations among the intensity of clustering, patch area, mean patch size, mean patch edge, and mean shape index of aspect patches.