海拔梯度对合江方竹发笋节律的影响研究

Study on the Effect of Altitudinal Gradient on Changes in Shooting Rhythm of Chimonobambusa hejiangensis

通过原产地对合江方竹不同海拔梯度发笋节律的观察和研究,得出其开始发笋期、停止发笋期及发笋数都随着海拔梯度的变化有显著或极显著的差异,海拔越高,发笋越早,停止发笋期也越早,平均发笋量3300株/667m2。其发笋期可以划分为开始期、高峰期和停止期阶段。在海拔1200m以上开始发笋期出现在9月中旬,停止生长期出现在10月上旬;1000m以下开始发笋期、停止生长期分别出现在9月下旬和10月底以后;随着海拔高度平均每降低100m,开始发笋期推迟2￣3d,停止发笋期随着海拔高度平均每降低100m推迟3￣4d。数学模型(以9月13日为第一天),发笋开始期为K=31.333￣0.02383H海拔,停止发笋期为T=64.867￣0.03217H海拔;合江方竹在不同海拔梯度的发笋性状可以划分成900m以下和900m以上两类,其中900m以下具有“笋期晚发笋多(晚多)”特性;900m以上具有“笋期早发笋少(早少)”特性。

By observing and analyzing the shooting rhythm of Chimobambusa hejiangensis that grow at different altitudes from 400m to 1200m,the paper come to the conclusion that at different alititudes there were significant or appreciably significant differences not only in the early and latc shooting period but also in budded shoots.The higher the altitude is. the earlier the early and late shooting period began.The shooting period could be divided into 3 stages that are the start,the flourishing and the stop ones.during which budded shoots at different altitudes averaged out to 49.5 thousand/hm^2.At the sltitudes abov1e200m.the atart stage began in the middle ten-dav;of Sep.and the stop stage in the first ten-day of October.At the altitude below 1000m;the start stage began in the last ten-day of Sep.and the stop stage not earlier than the end of Oct.With a mean altitude difference of 100m the start stage differed by 2 to 3 davs and the stop stage by 3 to 4 davs.The start and stop stages（presented by K and T.respectively）at different altitudes（presented by H）can be described by the equations K=31.333-0.02383 H and T=64.867-0.03217 H（with Sep.13 as the 1st day）,respectively.Below altiudes of 900m Chimonobambusa hejiangensis is characterized by a later shooting period and more budded shoots.whereas above altitudes of 900m it is characterized by an earlier shooting period and less budded shoots.