雷竹林冠层特性与叶片的空间分布

CHARACTERISTICS OF THE CANOPY AND SPATIAL DISTRIBUTION OF LEAVES IN \%PHYLLOSTACHYS PRAECOX C.D.CHU. ET. C. S. CHAO CV. PREVEYNALIS\% PLANTATIONS

研究了雷竹林的冠层特性和叶片的空间分布规律。结果表明 ,随着雷竹竹冠部位上升 ,分枝角度逐渐变小 ,而立竹密度变大 ,分枝角度略偏大 ;竹株不同留枝数量、胸径和林分不同立竹密度对叶量分布有较大影响 ,随着留枝盘数的增加 ,单株竹株的全叶重显著增加 ,在留枝盘数为 1 5～ 1 6档时 ,每株叶量最大 ;随胸径增大 ,全株叶重增大 ,在胸径为 3 7cm左右时叶量增幅最小 ,而后趋于平缓 ;立竹密度的增加 ,导致林冠叶量重心逐渐上移 ,立竹密度为 2 5 6～ 2 92× 1 0 4株·hm-2 ,林冠上层叶重比例达到 6 3 1 3%,林冠下层自然落叶现象明显。

A study on characteristics of the canopy and spatial distribution of leaves in \%P. praecox C. D. Chu. et. C. S. Chao cv. preveynalis\% shows that the higher the canopy, the smaller the angle between culm and branches while the angle between culm and branches is positively correlated with the density of a stand. The spatial distribution of leaves is greatly affected by the number of branches each bamboo has, DBH of the culm and the stand density. The total leaf weight of each bamboo is increased with the number of rounds of branches, with leaf quantity reaching maximum when there are 15～16 rounds of branches. A similar trend is found between DBH and the total leaf weight each bamboo has, with the latter being maximum when DBH is about 3 7cm, and no much changes are found in leaf weight when DBH is more than 3 7cm. Increasing the stand density leads to that the center of canopy gravity moves upwards. When a stand has a density of 25600～29200 bamboo per hectare, leaves in upper layer account for 63 13% of the total weight of leaves, with much litter found on the ground.