塔里木河下游胡杨树干液流特征研究

 以2005年5月至9月胡杨（Populus euphratica)树干液流及相关环境因子的实测数据,对塔里木河下游胡杨树干液流特征及其与环境因子的关系进行了分析。研究表明,胡杨树干液流的日变化表现为昼夜区别明显,7:30左右,液流开始启动,然后迅速上升,在10:30左右达到峰值,并在小幅度波动中维持到下午20:00左右。夜间,胡杨树干液流较弱。对不同月份典型天胡杨树干液流的实验分析表明,胡杨在5月初液流比较弱,5月中下旬液流逐渐增强,6月增强到较高的水平。7—9月胡杨液流都很强劲,其中9月典型天的液流最为强劲,胡杨树干液流季节变化与胡杨物候密切相关。分析胡杨树干液流与环境因子关系结果显示,胡杨树干液流和气象因子的关系密切,Pearson相关分析表明,胡杨液流流量和气象因子的相关性大小依次为光合有效辐射(PAR)>相对湿度(H)>气温(Ta)>风速(S)。

Study of Sap Flow in Stem of Populus Euphratica in Lower Reaches of Tarim River

Sap flow of Populus euphratica and its relationship with environmental factors were studied based on the experimental data of sap flow and environmental factors in the lower reaches of Tarim River from May to September, 2005. Results show that the flux of sap flow differs greatly from day to night, it starts at about 7:30, then rise rapidly and reaches its peak value at about 10:30, from 10:30 to 20:00, the sap flow remained at high level with a minor fluctuation, at night the sap flow is slow. In its growing season from May to September, the sap flow is weak in May, relatively strong in June, very strong in July to September. The seasonal change of sap flow of P. euphratica, closely relates to its pentad phenomenon. There is close relationship between stem sap flow of Populus euphratica and climatic factors. The results of Pearson Correlation Analysis show that the photosynthetic active radiation (PAR) is the most important factor, which is followed by relative humidity (H), then atmosphere temperature (Ta) and then wind speed(S).