宁夏南部长芒草草原退化等级评定方法探讨

On Assessment Method of Degeneration Grade of Bunge Needlegrass Grassland in Southern Mountainous Areas of Ningxia

通过调查和分析，确定长芒草草原退化的标志为：群落的植物种类成分，群落的盖度，生物产量以及长芒草的盖度、产量在群落中所占比重等５种群落学特征。按它们在群落中作用的大小，给予不同的指数系数，并通过评定指数数量化，确定退化等级。

It was determined through investigation and analysis that the indicators of degeneration of bunge needlegrass grassland are following 5 coenological characteristics: plant species composition of the community, cover degree and biological yield of the community, proportions of cover degree and biological yield of bunge needlegrass in the community. Coefficients were given to the indicators according to the significance of their role in the community. Finally the degeneration grades were determined on the basis of quantitation of the assessment indicators.