岩溶区青冈栎树干液流特征及其与环境因子关系

为阐明岩溶区植物液流变化特征,应用Granier 热消散探针法,连续测定了桂林岩溶区植物青冈栎1年整的树干液流密度变化,并用ICT-2000TE环境气象站同步监测林地环境因子。结果表明: 不同季节青冈栎树干液流密度差异较大,液流密度峰值分别为: 1月份36. 17g H2O /m2· s, 4月份62. 01g H2O /m2· s, 7月份63. 41g H2O /m2· s, 10月份39. 03gH2O /m2· s。土壤含水量在1月份、4月份、7月份与树干液流呈极显著相关;空气湿度和水汽压亏缺在1月份、10月份与树干液流呈极显著相关;空气温度在4月份、10月份与树干液流呈极显著相关,而光合有效辐射在所有的观测月份均与树干液流呈极显著相关。对各时期树干液流密度与环境因子的多元线性回归方程进行F 值检验,均达到极显著水平。 

Features of Quercus glauca sap flow and its relationship to environmental factors in karst terrain

Sap flow of Quercus glauca was measured continuously with Granier＇s thermal dissipation probe （TDP） method over a whole year in Guilin karst area. Meanwhile, the meteorological data were recorded by Environmental Meteorological Station. The results showed that the sap flux density （Js） of Q. glauca varied in different seasons with peak value of 36. 17gH2O/m^2·s in January, 62. 01gH2O/m^2·s in April, 63.41gH2O/m^2·s in July and 39.03gH2O/m^2·s in October respectively. Js was significantly correlated to soil moisture in Jan. , Apr. and Jul. , to the relative humidity （RH） of air and the vapor pressure deficit （VPD） in Jan. and Oct. , to air temperature in Apr. and Oct. , and to photosynthetically active radiation （PAR） in all seasons. Multiple linear regression models between sap flow and environmental variables were established for four separate seasons, each met the significance at 0.01 levels with F test.