不同黑杨无性系叶片及单木水平蒸腾特性研究

以廊坊地区杨树胶合板用材林主要造林树种中林46杨和廊坊杨为研究对象,应用快速称重法和热扩散茎流计分别观测了不同杨树叶片蒸腾速率和树干液流变化特征,旨在为该地区更精确地估计生态用水定额提供科学依据,而且也可为该区域杨树胶合板材林的造林、营林及流域综合管理提供理论基础。结果表明:无论晴天还是阴天,林木叶片蒸腾速率日变化都呈现有规律的单峰曲线,晴天表现为单峰宽峰曲线,阴天为单峰窄峰曲线;树干边材液流的日变化均表现出明显的昼夜规律;树干的测定方位不同,其液流速率存在着一定差异,白天均表现出一致的规律:树干南侧液流速率>树干北侧液流速率,而夜间树干南北液流速率大小相差不大,维持在0～2cm/h上下波动。

Study on consumption properties for leaf and individual level of different populus deltoides clones

The water consumption patterns of two poplars species, poplar ＇Zhonglin＇46＇ and popular Langfang which are main tree species of plywood forest in Langfang region, were studied in terms of quick weighting and thermal dissipation sap flow probe （TDP）. The leaf transpiration rate and sap flow variation characteristics of the poplars were measured. The aim of this paper is to understand the poplars water consumption mechanism, which would help to provide the base information for forest management, especially in ecological irrigation in the region, and furthermore to provide the theory about the afforestation, management and watershed management. It is revealed that： （1） the leaf transpiration rates（LTR） diurnal variation, no matter in the clear day or cloudy day, presented orderly an unimodal curve, of which there were wide peak curve in clear day and narrow peak curve in cloud day; （2） The poplars sap flow（SF） from day to night, showed the similar rules, which started to increase smoothly at 7：00 or 8：00 in the morning and would got the peak between the time of 11：00-15：00 that subjected to solar radiation increasing, circumference temperature rising and air relative humidity reducing, after that time, the SF would decrease steadily till 19：00 when it preserved a relative stabilization fiat, but it would reach the bottom before the time of sunrise; （3） the SF values probed in the stem varied with different directions, in the daytime the SF of poplars displayed the consistent rule： south side〉 north side, but at night both north and south stem SF rate varied not so much and maintained undulates about 0-2cm/h.