黄土丘陵沟壑区水分的植被生产力模型——以陕西清涧县为例

针对半干旱区水分的植被生产力问题,以黄土丘陵沟壑区典型地陕西清涧的人工刺槐林为研究对象,对植被生长量的成因进行理论假定和分析,结合该地刺槐的解析木分析资料和相对应的同期降水数据,研究了清涧地区刺槐生长与水分的关系,建立了该区水分一刺槐生长的半理论／半经验模型。结果表明：黄土丘陵沟壑区刺槐的材积生长率与水分的变化率具有较好的线性关系。

The vegetation productivity model to water in the gully-hilly Loess Plateau area

Water is the leading eco-factor which confines the plant's healthy growing at large extent in arid and semi-arid area such as the Loess Plateau area of China. Concerning the vegetation productivity of water especially soil water in semi-arid area,in this paper,a case study was done in Qingjian County,north of Shaanxi, which is located in the typical area on the Loess Plateau. Where,the productivity of Black Lo-custs,which means the timber growth amount here,by analyzing the sampled trees under the local precipitation condition and the corresponding precipitation data are analyzed,and then a semi-theoretical modei re-lating the timber growth and precipitation,which is based on a hypothesis about plant's biomass growth,is set up. The result shows that the timber growing rate of the Black Locusts has a nice linear relationship with the precipitation change annually, instead of the simple relation between timber growth amount and precipitation.