科尔沁沙地玉米茎流变化规律研究

Characteristics of Maize Sap Flow in Horqin Sandy Land

以Dynamax包裹式茎流测量系统对科尔沁沙地玉米的液流变化进行了连续监测,结合实验区自动气象站同步测定的光合有效辐射、气温、相对湿度和风速等气象因子以及人工记录的天气状况,分析了4种典型天气条件下玉米的茎流变化、蒸腾耗水规律及其与气象因子的关系。结果表明,不同天气条件下,玉米液流日变化波动曲线不同,影响液流量的主要气象因子也不同,光合有效辐射始终是液流变化的主导因子。晴天,玉米液流速率的日进程为"几"字型峰或单峰曲线;阴天,玉米的液流曲线通常呈多峰状态;风天和雨天是单峰曲线,或是呈不规则的多峰曲线。玉米茎秆液流通量密度的变化是各种气象因子综合作用的结果。单株日耗水量的总体变化趋势是从晴天、风天、阴天到雨天依次减少,其平均值分别为588,401,399和305g/h。

A Dynamax sap flow measuring system consisted of heat balance sensors was used to continuously monitor sap flows of corn（Zea mays） on Horqin sandy land,Northeastern China.The photosynthetic active radiation,air temperature,relative humidity and wind velocity were recorded synchronously by an automatic weather recording system.Based on the manual records of weather conditions,four most representative weather conditions were gathered up to analyze the relationship between sap flow,water consumption and meteorological factors.The results showed that the diurnal variations and affecting factors of sap flows differed with weather conditions.However,the photosynthetically active radiation was always the dominant factor affecting the sap flow.The diurnal sap flow changes of corn showed board peaks or single-peaked curves in sunny days,multiple-peaked curves in cloudy days,and single-peaked or irregular multiple-peaked curves in windy day and rainy day.The diurnal variations of sap flows resulted from comprehensive effects of multiple meteorological factors.The water consumption for an individual corn plant was the highest in sunny days,followed by windy days,cloudy days,and rainy days,with means of 588,401,399,and 305 g/h,respectively.