AN INVESTIGATION ON THE TRANSLOCATION AND CYCLING OF MAIN NUTRIENT ELEMENTS IN YOUNG MIXED STAND OF CUNNINGHAMIA LANCEOLATA AND MICHELIA MACCLUREI

In this paper,content of main nutrient elements (N,P,K,Ca,Mg),nutrient translocation,litter and its rate of weight loss during the period of one year in the pure young stand of Cunninghamia lanceolata and the young mixed-stand of C.lanceolata and Michelia macclurei were investigated.From these data,the conceptions of translocation and cycle of the nutrient element,in different stands were obtained.The results showed that the rate of translocation of nutrient elements in the needle leaves of C.lanceolata in pure stands is larger than that in the mixed stand,N contrary.The amount of litter in the mixed stands of C.lanceolata and M.macclurei is larger than that in the pure stands of C.lanceolata,the former is 1 039.95kg/ha.a,the latter 67.00 kg/ha.a.The rate of litter weight loss of C.lanceolata in pure stand and mixed-stand are 80.12% and 81.08% respectively.The rate of litter weight loss of M.macclurei is 59.17%.Because the speed of cycle of nutrient elements in the mixed-stand is faster than that in the pure stand,it is beneficial to improve the soil.Therefore,M.macclurei as a tree species for mixed-stand is suitable.