DCCA ANALYSIS OF PLANT SPECIES DISTRIBUTIONS IN DIFFERENT STRATA OF OAK (QUERCUS LIAOTUNGENSIS) FOREST ALONG AN ALTITUDINAL GRADIENT IN DONGLING MOUNTAIN, CHINA
Abstract:Aims Our objective was to study the relationship between plant species and environmental factors for different strata of a Quercus liaotungensis forest along an altitudinal gradient in Dongling Mountain, Beijing, China. Methods We collected 119 vegetation samples separately in the tree, shrub and herb layers along an altitudinal gradient and recorded environmental factors such as altitude and slope inclination and position. We used detrended canonical correspondence analysis (DCCA CANOCO 4.5) to determine the main environmental fact ors related to the distribution of plant communities. Important findings The DCCA axis 1 reflected the gradient in altitude, while axis 2 reflected slope position. Most species occurred at lower altitude. Species in the tree layer were distributed uniformly. A big overlap in the composition of the herb layer indicated that the microenvironment for species was similar. Species diversity increased from high to low altitude. According to the correlations among environment factors and results of the DCCA ordination, the most important factor affecting species distribution in this region was altitude.