太行山低山区不同植被群落蒸散与水量平衡研究

Evapotranspiration Process and Water Balance of Different Plant Communities in Lower Taihang Mountainous Areas

通过大型非称重式蒸渗仪方法对黄背草、荆条及二者之间的复合群落的蒸散过程及水量平衡进行研究，结果表明三种植被蒸散规律是以8月为峰值的单峰曲线，且7～9月为蒸散高峰期。三种群落蒸散量比较，5～6月黄背草蒸散量较其它两种植被群落高。然而其它月份蒸散量低，复合群落蒸散量高。三种群落土壤含水量均在7～8月份高，黄背草5～6月土壤含水量较其它两种植被低，9月后土壤含水量较其它两种植被群落高；土壤水势与土壤含水量有着相同的变化；三种群落水量平衡：整个生长季，11％～13％的降雨用于地下水的补给，87％～89％的降雨储存到土壤水库供植被生长。不同植被地下出流量变化不大，植被蒸散量不同主要是消耗土壤水不同所引起的。

The evapotranspiration （ET） and water balance of three typical vegetation communities were studied using large non - weighing drainage lysimeters. The vegetation communities include Themeda japonica community, Tanaka, Vitex negundo var. heterophylla community, and the mixture of them. The results indicated that ET had obviously seasonal changes, with the peak in August. Comparison ET of the three communities, Themeda japonica community had higher amount of ET than Tanaka, Vitex negundo var. heterophylla community and the mixture community from May to June. However, it was lower after June, but water moisture was higher from July to August. Comparison of water moisture of the three type communities, Themeda japonica community had lower amount of water moisture than Tanaka, Vitex negundo var. heterophylla community and the mixture community from May to June, while it was higher in the other months. Water potential had the same trend with water moisture. As to water balance, 11 - 13% of precipitation was drained, while 87% -89% of was stored in soil to supply plant growth. There were few changes on drainage among among the three communities.