割草地群落特征与土壤化学性质对利用年限的响应

Response of Community Characteristics and Soil Nutrients to Mowing for Different Years

对呼伦贝尔不同利用年限的贝加尔针茅(Stipa baicalensis)+日阴菅(Carexpe pediformis)和羊草(Ley-mus chinensis)+杂类草两种类型的割草地群落特征、植物营养成分及土壤营养成分进行了比较分析。结果表明,多年刈割使群落盖度降低,贝加尔针茅株丛破碎化、小型化,羊草退化;多年刈割的贝加尔针茅+日阴菅样地群落Mar-garlef丰富度指数、Shannon-Wiener多样性指数均高于同类型围封3年的样地,羊草+杂类草割草利用多年的样地Margarlef丰富度指数高于利用5年的样地。随刈割年限的增加,蔷薇科、菊科、毛茛科等一年生植物随之增加,地上生物量、枯落物现存量随着刈割年限的增加而降低;多年刈割使土壤有机质、全氮、速效氮的含量降低。

The community characteristics of Stipa baicalensis＋ Carexpe pediformis and Leymus chinensis ＋forbs utilized for different years,and nutrients of plant and soil in Hulunbeier were analyzed.The results showed that mowing for many years resulted in reduction of community coverage,and also made S.baicalensis cluster fragmentation and miniaturization and Leymus chinensis degradation.Margalef and Shannon-wiener index of S.baicalensis＋ C.pediformis mowed for many years were significantly higher than those in enclosure for 3 years,Margalef index of L.chinensis ＋forbs mowed for many years was higher than that grazed for 5 years.The annuals in Ranunculaceae,Compositae and Rosaceae gradually increased with the mowing years increased;community aboveground biomass and litter standing crops declined with the mowing years increased;soil organic matter,total N and available N content decreased with the increase of mowing years.