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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。
Taking Poplar 46 and Langfang Yang as the main afforestation trees of poplar plywood in Langfang area, the transpiration rate and the variation of trunk flow of different poplar leaves were observed by rapid weighing method and thermal diffusive sap flow meter, respectively Provide a scientific basis for more accurate estimation of ecological water quota in this area, and also provide a theoretical basis for the afforestation, silviculture and integrated management of poplar plywood forests in the region. The results showed that the diurnal variation of leaf transpiration rate showed a unimodal curve in both sunny and cloudy days, the unimodal broad-peak curve in sunny days and the unimodal narrow-peaked curve in cloudy days. The diurnal changes of stem sap flow All showed obvious diurnal patterns. The stems had different azimuths, and their flow rates were different during the day. The same pattern was observed during the daytime: the flow rate on the south of the trunk> the flow rate on the north of the trunk, Flow rate is not much difference between the size, maintained at 0 ~ 2cm / h fluctuations.