黑河地区绿洲生态条件下麦田生物气象若干特征

观测分析了ＨＥＩＦＥ地区绿洲中麦田的微气候特征，结果表明ＳＰＡＣ中水５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到气象因子的强烈影响和控制。冠层上方近地面风温湿的时间剖而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

Some biometeorological features of wheat field in the ecological conditions of oasis at the Heihe Region

We observed and analysed some characteristics of biometeorology over and within canopy in spring wheat field in the ecological conditions of oasis during HEIFE program.Water potential in SPAC appeared a well vertical profile and the profile showed an obvious diurnal variation.There were water potential jumps in the SPAC junction boundaries.Sequence of variation intensity for water potential in each part of the SPAC was atmosphere,plant and soil.It is shown that the water potential was influenced and controlled strongly by the process of plant water metabolism and up to meteorological factors.Atmosphere mixed well in day time in comparison with night time in near surface over the wheat field from the time space section of wind speed,ambient temperature and relative humidity.The structure of atmosphere was stable before sun raising.It revealed that the atmospheric features over wheat canopy in oasis were affected and controlled by hot and dry air from desert or Gobi.There were also ambient temperature,relative humidity vertical profiles within canopy as well as CO 2 concentration,PAR,leaf transpiration,photosynthesis,stomatal conductance and leaf surface temperature.The diurnal variations of profiles were drived mainly by the solar radiation,and in the same time,also were affected by the intensity of leaf water metabolism in different height leaf layer within canopy and soil status.The vertical profiles of ambient temperature and relative humidity within canopy appeared a quite different variation pattern in comparison with over canopy.