论文部分内容阅读
该研究应用热扩散式边材茎流计,对北京植物园绿地中元宝枫树干液流的时空变异特征进行了观测.研究结果显示:树干液流的日变化和季节差异与太阳辐射日变化和季节差异具有较好的一致性,夏季太阳升起比春秋早,落日比春秋晚,相应地树干液流启动夏季比春秋季早,进入低谷比春秋季晚;元宝枫为春季耗水性树种,树干平均液流速率春季0·00188cm/s、夏季0·00112cm/s、秋季0·00086cm/s;元宝枫树干液流存在明显的方位差异,同一样木,液流最大方位的流速可达平均值的122·1%,最小为平均值的86·3%,在同一株样木上,液流的方位差异较为稳定,不同样木液流最大和最小的方位不同,树干液流的方位差异与冠幅大小无关;在垂直高度上,春夏两季上部液流的波动节律明显早于下部和中部,液流速率上部最大,中部次之,下部最小.
In this study, the thermal diffusive sap flowmeter was used to study the spatio-temporal variation characteristics of the dry-land flow in the Yuanmingbao maple in Beijing Botanical Garden.The results showed that the diurnal variation and seasonal variation of the sap flow and the diurnal variation of solar radiation and season The difference was better. The rising of summer sun was earlier than that of spring and autumn, and the setting sun was late than that of spring and fall. Correspondingly, the trunk flow started the summer earlier than the spring and autumn and entered the trough than the spring and autumn. The flow rate was 0 · 00188cm / s in spring, 0 · 00112cm / s in summer and 0 · 00086cm / s in autumn. There was a significant difference in azimuthal flow in the stems of A. sinensis, 122 · 1%, the minimum is 86.3% of the average. In the same sample, the azimuthal difference of liquid flow is relatively stable. The maximum and minimum orientations of different sample flow are different. At vertical height, the fluctuation rhythm of the upper stream in spring and summer is obviously earlier than that in the lower part and the middle part. The upper part of the flow rate is the largest, the middle part is the second and the lower part is the smallest.