| Platycladus orientalis is one of the most predominant plantations in northern China, especially in Beijing area, forest area accounts for about 26.2% of the city's forest cover. It has an important impact on the whole Beijing ecological, economic and social, and research plantation forest hydrological effect under conditions of different forest structure, to reveal the coupling mechanism, water and ecological processes between the hydrological effects of great significance for the further Platycladus orientalis plantation water science management and operation to provide a theoretical basis. Selecting the Platycladus orientalis plantation in Jiulong Mountain as the research object, which study the different structures(under branch height, canopy density) forest hydrological effect on the basis of setting experimental plots. Based on observations in 2015, mainly from the canopy layer, litter layer and soil layer three aspects, respectively, to explore the relationship between different levels and forest between hydrological effects, and to affect the structure of the forest makes a preliminary analysis of temperature, the main conclusions of the following:(1) In Beijing Jiulong Mountain area in flat water year. The throughfall rate of under branch height of 1/2 in level of 0.4,0.6,0.8 are respectively 84.4%,79.7%,75.8%, their stemflow rate are 5.5%?4.5%?3.6%, and their canopy interception rate are 10.1%?15.8%? 20.5%; The throughfall rate of under branch height of 1/3 in level of 0.4,0.6,0.8 are respectively 80.2%,74.0%,65.6%, their stemflow rate are 4.9%?3.8%?2.3%, and their canopy interception rate are 14.9%?22.2%?32.0%.(2) Based on the observation data of rainfall in 2015, regression analysis showed that the correlation between throughfall, stemfall and rainfall was well fitted quadratic polynomial, than linear model can better explain its physical meaning; The relationship between interception and rainfall with a single modecule fits better; The relationship between throughfall rate and rainfall with exponential function fits better; And the relationship between interception rate and rainfall with power function fits better. Throughfall rate, stemfall rate increases as rainfall sharply, followed by an increasing trend slowed down; With the increase of rainfall, interception rate decreases sharply, then decreases slowing trend, finally tends to a stable value.(3) In this paper, the Wang Yanhui model(Ic-?[1-e(-P/a)]+bP) and exponential model(Ic-a(1-ebP),Ic=aPb) can be well explained by interception from the physic point of view, and from the simulation results, these three models could fit interception with Platycladus orientalis plantation of different structures precisely.(4) The ralationship between throughfall, rainfall and litter interception with power function fits better in Beijing Platycladus orientalis plantation, regression equation by F test and t test were significantly. The relationship between litter interception and rainfall exists significant positive correlation, and existence of a negative correlation between litter interception and rinnai humidity, but there is no significant relationship between other factors. The model(I=a(1-ebP)) simulate the ralationship between rainfall and litter interception, the value of the parameters of the model in the application of the model has good stability, with analysis of variance, litter interception between different canopy density exits significant diffrernces, but the model has limitations in the application.(5) Each stand is consistent dynamic changes of soil moisture evaporation. Different canopy density between soil evaporation volume at every significant differences with a high condition. Different branches canopy density under the same conditions of high stand between soil evaporation also showed a significant difference. |
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