A STUDY OF CHEMICAL CONTENTS IN A MIXED SHRUBLAND NEAR BAIHUASHAN MOUNTAIN IN BEIJING
北京百花山附近杂灌丛的化学元素含量特征

Spiraea dasyantha, Myripnois dioica, Vitex negundo var, heterophyllaare the three co-dominant spieces in a mixed shrubland in the region ofBaihuashan Mountain. According to the chemicae content analysis of theplants (leaf, stem, branch, lateral root, taperoot) and soil in this study,it was found that different plants and different organs have very diffe-rent contents of all chmical elements and content variation in differentseasons. Ca and N have the highest accumulation among the tern elemtntsanalysised in this shrub community. In the herb layer, the first six ele-ments of accumulation are in the order of Ca>N>Al>Fe>K>Mg andCa>N>Al>Fe>Mg>K in the litter layer, Ca>N>K>Mg>Fe>Al inthe shrub layer. Ca was found to have highest content in soil nutrientpool and N is the second one also. The other eight elements are in theorder of Na>Mg>K>Mn>Al>Fe>Zn>Cu. Thus the chemical contentof plant and soil are related. The accumulation index, the ratio of accu-mualtion of nutrient elemtnts in plants to that in soil, can reflect therelationship. K, Fe and Al have the highest accumulation coefficient andNa has the lowest one.