Effect of Grazing-prohibited on the Vegetation Restoration of Degraded Grassland in A’ba County

27 Mar Effect of Grazing-prohibited on the Vegetation Restoration of Degraded Grassland in A’ba County

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Abstract

２００３～２０１０年对四川阿坝县退牧还草工程禁牧区 草 地 植 物 群 落 结 构 进 行 了 定 点 研 究，结果表明：退牧还 草工程禁牧区草地群落的物种丰富度随禁牧年限的增加表现上升趋势，２０１０年的物种丰富度比２００３年增加了７；群 落的Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ多样性指数和 Ｐｉｅｌｏｕ均匀度指 数 均 随 禁 牧 年 限 的 增 加 呈 增 加－ 下降－ 增加趋势；禁牧期间 莎草科植物鲜重占植物群落总鲜重的比重随禁牧年限增加而增加，有毒和杂类草植物比重从２００３年到２０１０年下降 了３１．２６％。把禁牧区与对照区种丰富度、群落的 Ｓｈａｎｎｏｎ－Ｗｉｅｎｅｒ多样性指数和 Ｐｉｅｌｏｕ均 匀 度 指 数 进 行 样 本 配 对，用符号平均秩检验法（Ｗｉｌｃｏｘｏｎ）进行差异显著性检验得出 Ｐ 值分别为０．０１７８、０．０１１６、０．０１７３，均小于０．０５ 水 平，表明禁牧对草地群落结构优化效果明显有利于退化草地的正向演替。

English Abstract

Grassland plant communities in grazing-prohibited area of returning farm land to grazing land project in A’ba County were studied from 2003 to 2010.The results showed that the species richness index was growing up with the year going on in grazing-prohibited area of returning farm land to grazing land.The species richness in 2010 was increased by 7 compared with that in 2003.With the increase of the grazing-prohibited years the Shannon-Wiener Index and Pielou Index of plant community showed low-highlow tendency.Fresh weight of plants in Cyperaceae accounted for the total fresh weight of plant community increased in grazing-prohibited period,the toxic plants and forks proportion were decreased by 31.26%.The differences in Species Richness Index,Shannon-Wiener Index and Pielou Index were tested with Wilcoxon method between grazing-prohibited area and control area,Pvalues were 0.0178,0.0116,0.0173 respectively(P0.05).These results showed that the effect of grazing-prohibited on the vegetation restoration was significant.