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观测分析了 HEIFE地区绿洲中麦田的一些微气候特征 ,结果表明 SPAC中水势随高度呈显著梯度分布 ,在土壤 -植物以及植物 -大气界面 ,水势值存在两个大的跳跃 ;水势廓线存在明显的日变化 ;SPAC各部分水势变化的起伏顺序是大气 >植物 >土壤 ,说明水势变化受植物水分代谢进程直至气象因子的强烈影响和控制。冠层上方近地面风温湿的时空剖面显示出白天与夜晚相比 ,大气混合得较好 ;日出前则大气较为稳定 ;在典型晴天条件下 ,麦田上方的大气存在内边界。其结构受来自沙漠干热风的影响和控制。冠层内部也存在着温度、湿度、CO2 浓度、PAR、蒸腾作用、光合作用、气孔导度和叶温的垂直梯度 ,其廓线的日变化主要受太阳辐射的强烈控制 ,同时也受冠层内部不同层面叶片水分代谢强弱以及土壤状况的影响 ,其温湿廓线表现出与冠层上方不同的变化模式。
Some microclimate characteristics of wheat field in oasis in HEIFE area were observed and analyzed. The results showed that the water potential in SPAC showed a gradient distribution with height. There were two big jumps in water potential value at soil-plant and plant-atmosphere interface. The water potential profile was obvious . The order of fluctuation of water potential in each part of SPAC is atmosphere> plant> soil, indicating that the change of water potential is strongly influenced and controlled by the process of plant’s water metabolism until meteorological factors. The temperature and humidity profiles of the near-surface winds above the canopy show that the atmosphere mixes better during the day and night than before; the atmosphere is stable before sunrise; and the atmosphere above the wheat field has an inner boundary under typical sunny conditions. Its structure is affected and controlled by dry and hot wind from the desert. There are also vertical gradients of temperature, humidity, CO2 concentration, PAR, transpiration, photosynthesis, stomatal conductance and leaf temperature in the canopy. The diurnal variation of its profile is mainly controlled by the solar radiation and also by the canopy The results showed that the temperature and humidity profiles showed different patterns of change from those above the canopy.