皇甫川流域主要人工灌木水分生态的研究

通过在丰水年(1998年)和欠水年(1999年)连续两个生长季对皇甫川流域主要灌木沙棘、沙柳和柠条的生物学特性、蒸腾特征及土壤水分含量的测定及分析,得出结果为:三种灌木蒸腾强度在晴天和阴天表现的日变化规律不同。在丰水年和欠水年的生长季内,三种灌木蒸腾强度均随土壤含水量和降雨量的增减而增减,环境因子综合作用于灌木蒸腾的过程。无论丰水年还是欠水年,三种灌木地上生物量的增长与蒸腾耗水量均呈同步增长,生长季内皇甫川流域主要灌木蒸腾系数均较高,灌木的生长是以消耗大量水分为代价,水分是其生长的主要限制因子之一;柠条蒸腾系数较小,这反映了柠条能较有效利用水分,积累干物质,适合于在皇甫川流域生长;通过测定与计算,皇甫川流域沙棘适宜盖度为61%～79%、柠条为43%～55%、沙柳为46%～59%。

A study on the water ecology of dominant artificial shrubs in Huangfuchuan watershed

According to the field monitoring data in the growing season of a water abundant year(1998)and a water deficient year(1999),this paper deals with water regime of three dominant shrubs-- - Hippophae rhamnoides,Salix psammophyla and Caragana intermediai in Huang-fuchuan watershed.The results show daily changes of the transpiration intensity of the three dominant shrubs have different characters in sunny days and cloudy days.In sunny days,the dai-ly changes of the transpiration intensity of S.psammophyla and C.intermedia have double peaks and noon depression,while H.rhamnoides has single peak without noon depression.In cloudy days,the daily changes of transpiration intensity of these three dominant shrubs have single peak without noon depression.In both the abundant year and the deficient year,the transpiration inten-sity of the three dominant shrubs shows similar seasonal variations.It fluctuates with the in crease and decrease of soil water content and precipitation.The correlation between transpiration of the dominant shrubs and soil water content is different from each other.The transpiration of H.rham-noides correlates closely with soil water content,but the relationships between the transpiration of the other two shrubs and soil water content are insignificant The above-ground biomass and water consumption of the three dominant shrubs showed synchronized increase in both abundant and deficient year.In deficient year,the above-ground biomass and water consumption of the three dominant shrubs reach the highest values in July,but reaching the highest values in August in abundant water year.And in growing season,transpiration coefficients of all the domi nant shrubs are very high.It is thus concluded that the shrubs grow at the expense of vast amount of water content which is one of the main limiting factors.The transpiration coefficient of C.intermedia is the smallest,this indicates that C.intermedia consumes water and accumulates dry matter more ef-ficiently than others,so it is more suitable to Huangfuchuan watershed.Under condition of water balance in Huangfuchuan watershed,suitable coverage of H.rhamnoides is61～79%,C.intermedia is43～55%and S.Psammophyla is46～59%.