晋西黄土区封禁流域植被群落组成及物种多样性变化

Vegetation community composition and species diversity change in the closing area of Loess Plateau of western shanxi province

以晋西黄土区蔡家川封禁26年的小流域为研究对象,采用样线调查技术,对其植被群落特征进行了调查。结合1996年的调查资料,对6种生境类型在不同封育年限条件下群落的物种组成变化进行了对比分析,并运用物种多样性指数、均匀度指数以及生态优势度对调查区域群落物种多样性进行了分析。结果表明:随着封育年限的增加,乔木树种的比例有所上升,灌木的比例有所下降,群落中乔灌木物种更为均衡;研究区域群落整体上物种多样性指数、均匀度指数均有显著提高,生态优势度有所下降,群落朝着更为丰富、均匀、稳定的方向发展。

With the small area of Cai Jiachuan closed for 26 years in the loess plateau of western Shanxi province as the studying object, this paper selected the linear investigation to study the characteristics of its vegetation community. With the combination of the investigation data of 1996, the changes of community composition of 6 habitat types with different closing years were analyzed and compared, and the species diversity index, uniformity index and ecological dominance were used to analyze the species diversity in the community of the investigated area. The result indicted that, with the increasing of the closing year, the proportion of the arbor trees grew, the proportion of the frutex inclined, and the rate between the two appeared to be more balanced. The species diversity index and uniformity index increased significantly, but the ecological dominance inclined, and the community developed towards the tendency which was richer, more balanced and stable.