THE RELATIONSHIP BETWEEN THE CLONAL GROWTH AND THE DENSITY OF ADULT SHOOTS WITH DIFFERENT LEAF AGE IN PHYLLOSTACHYS PUBESCENS MAZEL
毛竹的无性系生长与立竹密度和叶龄结构的关系

Phyllostachys pubescens ,a typical clonal plant,is a monopodial bamboo species native to subtropical China.Its shoots are widely separated each other.Because of its giant size,fast growth,high production,good quality for timber use and wide distribution,it has long been the most important economic bamboo in China.Based on the theory of physiological integration in clonal plants,this paper deals with the influence of the density of adult shoots and leaf age structure on the potential of clonal growth in Phyllostachys pubescens from the point of view of demography.It was shown that because the leaf life span is two years in this bamboo,new (1 year old) leaves had higher photosynthetic capacity than old (2 year old) leaves.The number of new shoots emerging and surviving per plot was positively correlated with the number of adult shoots with new (1 year old) leaves,rather than with that of those with the old.In addition,the mortality of new shoots was density independent.This result may explain the common pattern of alternating fluctuation in the production of new shoots between successive years.