Study on Crown Structure and Function of Phyllostachys pubescensStands for Culm and Shoot Production

The relationship between crown structure and productivity of Phyllostachys pubescens stands for culm and shoot production was studied.The results showed that with certain stock density (2 250～3 150 culms per hectare),under the disturbance of artificial management,the crown width was less influenced by density,but correlated closly with DBH,clear bole height and total height (DBHtotal heightclear bole height).Site quality had significant effect on the yield of bamboo stand,especially on stocking,but less affected the crown width. The crown layer of P.pubescens stand obeyed the vertical and horizontal distribution pattern,which benefited stocking bamboo to fully utilize the soil nutrient elements.A model for estimate the relationship between bamboo yield and stand structure factors was established:G=-302 27+42 08M-0 000 56N+15 94D+29 37h-9 32H.The crown width could be used as a factor to estimate stand productivity.