敦煌葡萄液流特征及耗水分析

基于热平衡原理,运用FLOW32包裹式植物茎流计对甘肃敦煌南湖地区无核白葡萄液流速率进行长期连续观测,并对多个气象因子开展同步测定,分析探讨不同天气条件下葡萄液流速率及气象因子的日变化特征,进行了液流速率与各气象因子的回归分析,建立了液流速率的多元曲线回归模型,分析了葡萄树的耗水规律.结果表明:在不同天气条件下无核白葡萄树液流速率日变化差异显著,日均液流速率晴天 > 阴天 > 雨天;液流速率与光合有效辐射、水汽压亏缺呈线性相关,与冠层温度、冠层相对湿度呈曲线相关,相关程度大小顺序为光合有效辐射 > 水汽压亏缺 > 冠层温度 > 冠层相对湿度;建立液流速率的多元曲线回归模型,为研究葡萄树潜在耗水能力提供了预测手段;对比分析了无核白葡萄树的耗水量,为当地农业灌溉及种植等提供了合理化建议.

Analysis of Variation of Sap Flow Velocity and Water Consumption of Grapevine in the Nanhu Oasis,Dunhuang, China

By using FLOW32 sap flow sensors, the researchers employ the heat balance method to study sap flow velocity of grapevine in the Nanhu Oasis in Dunhuang, China. After detecting meteorological factors by automatic weather station, the paper analyzes the diurnal fluctuations of sap flow velocity of grapevine under different weather conditions, and conducts simple regression analysis between sap flow velocity of grapevine and meteorological factors, and establishes a multiple linear regression model to analyze the water-consuming pattern of grapevine. The result shows that, sap flow velocity varies in different weather conditions with statistical significance: the daily mean on sunny days is greater than that on cloudy days, with the rainy days the lowest. Analysis of partial correlations and regression analysis between sap flow velocity of grapevine and the main meteorological factors show that, sap flow velocity of grapevine correlates linearly with photosynthetically active radiation (PAR) and vapor pressure deficit (VPD), and correlates curve-linearly with canopy temperature (CT) and canopy relative humidity (CRH) in the pattern of PAR > VPD > CT > CRH. The result of multiple regression modeling can help better predict water consumption of grapevine (R²=0.95), and comparative analysis of water consumption of grapevines can help improve the local agricultural watering and planting.