Wang Hua, Ouyang Zhi-yun, Zheng Hua, Ren Yu-fen, Gao Fu-yuan
Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Ying Yong Sheng Tai Xue Bao. 2011 Mar;22(3):571-6.
In order to clarify the environmental factors affecting the water use of typical urban tree species Magnolia liliflora, an investigation was conducted on the responses of M. liliiflora whole-tree sap flow to the air temperature, air relative humidity, radiation, wind speed, soil temperature and water content, and precipitation in Beijing from April to October, 2008. The eight environmental factors affecting M. liliiflora whole-tree sap flow could be divided into three categories, i.e., evaporative demand index, soil index, and precipitation index. The evaporative demand index (air temperature, air relative humidity, total radiation, wind speed, and vapor pressure deficit) could explain 60% of the variation in the sap flow of individual trees, which presented S-type change trend, i.e., the sap flow reached an asymptote where higher light and evaporative demands could not cause sap flow to increase further. Soil index (soil temperature and water content) and precipitation index (precipitation amount) had little influence on the sap flow.
为阐明影响典型城市树种紫玉兰水分利用的环境因素，于2008年4月至10月对北京紫玉兰整树液流对气温、空气相对湿度、辐射、风速、土壤温度、土壤含水量及降水量的响应进行了调查。影响紫玉兰整树液流的8个环境因素可分为3类，即蒸发需求指数、土壤指数和降水指数。蒸发需求指数（气温、空气相对湿度、总辐射、风速和水汽压差）可解释单株树木液流变化的60%，液流呈S型变化趋势，即液流达到渐近线，较高的光照和蒸发需求不会导致液流进一步增加。土壤指数（土壤温度和含水量）和降水指数（降水量）对液流影响较小。
