Water Consumption Of Compound Plant Ecosystem And Effect Of Canopy Densities On Turfgrass Evapotranspiration Research In The Summer Palace

In recent years, the water management of Greenland in Beijing is constantly trying to develop and popularize spray, drip, infiltrating irrigation and other forms of irrigation. The basic irrigation method in most of areas is sprinkler, but for some reasons, such as improper operation or misunderstanding etc, excessive spraying formed invalid infiltration and runoff caused the loss of water resources. Tall trees are mostly irrigated by tube directly, which not only caused the increase in water consumption, but also made the water mainly concentrated in the surface of soil and the upward growth of tree roots, trees caused lodging which results in the insufficient of irrigation.Study on the water consumption of compound plant ecosystem is valuable to direct the water-saving irrigation of a garden. The experiment was carried out in the Summer Palace from April to November in 2007. In this study, the temporal and spatial variation of the soil water content and soil water potential was measured everyday under different compound plant ecosystems, which include: arbors and turfgrass, shrubbery and turfgrass, turfgrass. The irrigation amount and rainfall were measured during the experiment Based on distributed water balance method; The temporal and spatial variation of the water consumption of the three kinds of ecosystem was analyzed. The result showed that the redistribution of rainfall and the irrigation had great variance in the compound ecosystem, and there has a certain difference among different complex system in water consumption and leakage situation.Gardens complex system of the complexity of vegetation types, leading to the irrigation district and the effectiveness of the uneven distribution of rainfall,all of the different compound plant ecosystems had two water peak performances: a major focus on 5-6 and the second in August. But there had less water evaporation in July because of the rainfall and cloudy weather; The arbors and turfgrass, and the turfgrass had lower water consumption, higher leakage. The shrubbery and turfgrass had a higher water consumption, lower leakage.Other then, the experiment was carried out to study the effect of canopy densities on the evapotranspiration of turf grass using micro-lysimeters. The results showed that increasing the canopy density would decrease the evapotranspiration of turf grass significantly, but this effect would be weak above 0.6 canopy densities. And the exponential curve relationship between the evapotranspiration of turfgrass and canopy density above it was found.The position of nozzle should be designed according to the shade of the trees and the water consumption of trees. At the same time, in the dry season, on the base of plants distribution and weather, we can make certain the irrigation water quota and irrigation interval. In the rainy season, we should stop the working of irrigation system to prevent water leakage, and pay attention to drainage.