退化羊草草原的群落蒸发蒸腾

草原群落蒸发蒸腾是一个由多种因素综合影响的复杂问题。本文在天然羊草草原上,以畜群点为中心由外向内,选择退化程度不同的放牧空间梯度系列替代退化演替时间梯度系列,用土柱称重法进行群落蒸发蒸腾观测,深入分析了羊草草原退化群落蒸发蒸腾的变化规律。得出:天然羊草草原在土壤供水较为充足的情况下,随着放牧强度的增加,群落生物量减少,盖度减少,蒸腾减少,蒸发增加,但蒸散减少不明显。

Community Evapotranspiration on the Deteriorated Series of Leymus chinensis Steppe

The evaporation and transpiration of the steppe communities is a complex problem influenced by many factors.On the natural Leymus chinensis steppe,the paper substituted time gradients of deteriorated succession with centralwards gradients of grazing on different plots of grazing intensity,and further studied the regularity of community evaporation and community transpiration of the steppe by measuring soil column.The results are as follows:Community evaporation increases and community transpiration decreases with biomass and cover of community falling down when grazing intensity rises,but the decrease of community evapotranspiration is not obvious.Simultaneously,community T/ET is steady relatively from the no degraded plot(N) to the over-degraded plot(O) on the deteriorated succession series of Leymus chinensis steppe.So community T/ET from the gradient N to the gradient O can be called T/ET stability phase.