宁夏荒漠草原不同坡位群落特征研究

采用样线调查法,对宁夏封育的退化荒漠草原进行植被调查.对不同生境群落物种组成进行PCA（principal components analysis）排序.结果表明：在整个采样尺度上,不同生境群落植被组成存在差异,不同坡位导致植被类型在小范围内发生明显替代,这种替代来自于不同生活型的物种之间;群落建群种为针茅、赖草、胡枝子等优良牧草;一二年生草本、多年生杂类草的比例有一定程度的增加;老瓜头、刺叶柄棘豆等荒漠草原退化的指示种在群落中的比例减小.

Study on the community characteristic in different slope locations on desert steppe in Ningxia

The characteristic of desert plant community in different habitat were studied by taking desert steppe in Yanchi Count of Ningxia Province as an example.The line transect method used to survey the vegetation in the field.Using PCA(principal components analysis) ordination to analyze the components of communities in slope scale.The results showed that the components of communities did not change significantly.After a long time of fencing,the proportion of fine varieties of herbage increased,community structure had improved.Dominant species from Cynanchum komarovii,Artemisia sacrorum to Stipa bungeana,Leymus secalinus,Lespedeza davurica.The percentage of indicator organism such as Cynanchum komarovii,Oxytropis aciphylla decreased obviously.Vegetation types were clearly differentiated in slope scale,different slope locations bring about vegetation differentiation.