三峡库区消落带植物治理措施

Plant management measures on water-level-fluctuating-zone in Three Gorges Reservoir Area

根据三峡库区消落带的水土流失程度及库区水位变化规律,将145～152 m、152～170 m、170～177 m的消落带分别划为消落带下端、消落带中端与消落带上端,并以三峡库区185 m观景平台的上游消落带生态治理试点为例,采取植物与工程相结合的治理模式,通过选取植被覆盖率、物种种类、物种多样性、植物生长基质流失量4类指标,对试验区的生态修复效果状况进行监测分析。结果表明:试验区的植被覆盖率沿消落带梯度方向从上至下在观测期内逐年降低;物种种类因受库水长时间的淹没有所减少,均匀性随高程的不同也呈现较大差异,α多样性指数在监测期内随时间的增长逐年降低;库岸受库水的长期浸泡以及浪涌的高频繁冲刷是消落带植物生长基质流失的关键因素,造成消落带上下两端植物生长基质流失比中端严重的主要原因为行船所产生的涌浪,且其随时间的增长日趋严重。

According to the degree of soil erosion and the change rule of water level of water-level- fluctuating-zone in Three Gorges Reservoir Area, this paper divided the water-level-fluctuating-zone into three zones, 145- 152 m （bottom zone）, 152- 170 m （middleend zone）, 170 -177 m （top zone） respectively. The ecological management mode of combing plant and engineering measures were conducted at the 185 m observation platform upstream in Three Gorges Reservoir Area. Four kinds of indices including vegetation coverage, species, species diversity, the loss of plant growth matrix, were selected to analyze the effect of ecological restoration. The results show that the vegetation coverage along with the slope surface of water-level-fluctuating-zone from up to down reduced year by year in experimental observation period. As submerged by water for a long time, the types of species reduced, the uniformity presented great difference with different elevation, and the alpha diversity index reduced as time goes on during the monitoring period. Bank soaking and frequent surge scouring for a long time led to the loss of plant growth matrix, and the surge which produced by voyaging was the main reason led to the loss at the bottom and the top part being more serious than the middleend section. The loss of plant growth matrix became more serious as time goes by.