三倍体山杨苗期形态特征及生长节律的调查

STUDIES ON MORPHOLOGICAL CHARACTERISTICS AND GROWING REGULARITY DURING SEEDLING STAGE OF POPULUS TREMULA×P. tremloides [3N]

通过对三倍体山扬苗期形态特征及生长节律的观测，发现该品种干形通直，分枝角度小，可提高林地生产力；其苗高、地径生长迅速，年均生长量分别为1．87m、1．77cm，是优良的山地造林树种；苗高、地径生长量的大小与气象因于密切相关，自6月中旬开始；随温度的升高，苗高生长逐渐增高，7月上旬达到高峰，之后随温度升高苗高生长呈下降趋势，地径生长较平稳；当8月上旬温度、降水达到高峰时，地径生长达到高峰，高生长缓慢，一些苗木受高温影响而封顶。

The morphological characteristics during seedling stage and growing regularity of Populus tremula×P. tremlides [3n] were investigated. The results showed that stem shape was very straight,branch angle was small, the stands preductivity was increased. Height and ground - level diameter grew rapidly, annual average increment was 1. 87m and 1. 77cm, respectively. It is a gdri tree variety for afforestation on mountain areas. The increment of height and ground - level diameter was closely correlative with meteorological factors. Height growth increased gradually as temperature went up from the second ten dape of June and reached the peak in the first ten days of July, height growth presented a trend of decreasing after that time as temperature went up. Grond - level diameter grew smcothly and reached the peak when temperature and rainfall reached the peak in first ten dape of August, height growth was very slow and stoppped under the influence of high temperature.