宁夏主要沙地草地植被数量波动研究

Vegetation Quantity Fluctuation of Main Sandy Land and Grassland in Ningxia

植被波动是植被动态的一种表现形式,选择宁夏沙地面积最多的中卫市、盐池县为研究对象,研究2003—2008年草地植被数量波动及波动率,从数量特征上对草地植被波动进行探讨。结果表明:盐池县草地正向波动以2004年最好,波动率为0.110 5;负向波动最大是2008年,为-0.144 9。中卫市正向波动以2007年最好,波动率为0.274 1;负向波动最大是2008年,为-0.262 1。中卫市和盐池县植被波动趋势一致,但盐池县沙地植被波动幅度小于中卫市沙地植被。结合降水量数据,发现植被波动强度曲线与降水量曲线基本一致,表明植被波动曲线确实能较好地反映研究区的植被生长情况。

Vegetation fluctuation is a form of vegetation dynamics. Taking the districts with largest areas of sandy land in Ningxia, namely, Zhongwei municipality and Yanchi county, as examples, the grassland vegetation quantity fluctuation and fluctuation ratio from 2003-2008 were studied. The results showed that in Yanchi, the most positive fluctuation ratio is0.110 5 in 2004 and the most negative ratio-0.144 9 in 2008, and that in Zhongwei are 0.274 1 in 2007 and-0.252 1in 2008 respectively, which indicated that vegetation fluctuation trend was consistent in these two areas while sandy land fluctuation in Yanchi is less than that in Zhongwei. Combined with rainfall data, it was found that the vegetation fluctuation curve was in accordance with the rainfall curve, indicating that vegetation fluctuation curve could reflect the vegetation growth in research areas effectively.