科尔沁沙地植被生产力对模拟增加降水和氮沉降的响应

Responses of vegetation productivity in Horqin Sand Land to simulated increased precipitation and nitrogen deposition

采用随机区组设计,利用降水收集装置和地表施氮处理,模拟降水和氮沉降增加对科尔沁沙地典型小叶锦鸡儿群落植被生产力的影响。结果表明:降水量增加1/7,植被平均高度增加不明显,植被生物量增加了17.6%;降水量增加2/7,植被平均高度增加了23%,植被生物量增加了31.8%;模拟氮沉降处理的一年处理结果对植被生物量增加不明显;降水是影响沙地植被生产力的关键因素,植被生产力对降水量增加响应迅速,短期的氮沉降对植被生产力的影响不显著。

By using precipitation collection device and with ground surface nitrogen application,a randomized block design was adopted to study the effects of simulated increased precipitation and nitrogen deposition on the vegetation productivity of typical Caragana microphylla community in Horqin Sand Land.When the precipitation increased by 1/7,the mean vegetation height had no significant increase,but the vegetation biomass increased by 17.6%.When the precipitation increased by 2/7,the mean vegetation height increased by 23%,and the vegetation biomass increased by 31.8%.One-year nitrogen deposition had no significant effects on vegetation biomass.Therefore,precipitation could be the key factor affecting the vegetation productivity on sandy land.The vegetation productivity had a rapid response to increased precipitation,while short-term increased nitrogen deposition had little effects on the vegetation productivity.