NOHLINEAR ORDINATION OF THE PERMANENT PLOTS OF EVERGREEN BROAD-LEAVED FORESTS IN SIMIAN MOUNTAIN OF SICHUAN PROVINCE
四川江津四面山常绿阔叶林永久样地的非线性排序

Twenty permanent quadrates of 50 x 10m2 in evergreen broad-leaved forest in Simian Mountain of Sichuan Province were ordinated according to the important values of the dominant tree species using the techniques of principal component analysis (PCA), detrended principal component (DPC) and nonmetric multidimensional scaling (NMDS). The results of PCA demonstrated a nonlinear relations existing in the data; and a further analysis of DPC confirmed the existence of the strong nonlinear relations. While the results of NMDS clearly revealed the relationship between dominant species and environmental factors; which provided a fundamental base for further study on the secondary succession of the forests in the permanent site.