Title: Effects of Vegetation Cover Change of Alpine Kobersia Meadow on Plant Community Structure and Diversity in Source Region of the Yangtze and Yellow River
Abstract: The effect of vegetation cover change on plant community structure and species diversity of alpine Kobersia meadow was studied in Qinzheng of Gande County of Qinghai Province.The results showed that the species number is 33 on light degraded grassland,and dominant species is Kobresia pygmaea and subdominant species are Potentilla nivea,Saussurea superba and Festuca ovina.The species number is 41 on medium degraded grassland,and dominant species is Kobresia pygmaea and subdominant species are Oxytropis melanocalyx Ligularia virgaurea and Stipa aliena.On severely degraded grassland,the species number is 37,dominant species are Aster alpinum and Ligularia virgaurea,and subdominant species are Artemisia annua,K.humilis and Morina chinensis.The percentage of Species number occupying total species number of study site on light,medium and severely degraded grassland are 58.93%,73.21% and 66.07%,respectively.Dominance of Kobersia pygmaea decreased with the degradation of grassland.The rate of dominance is 27.13%,12.37% and 1.82% for light,medium and severely degraded grassland,respectively.Along grassland degradation series,Kobresia pygmaea that reproduce by clone in an alpine environment disappears gradually while the species such as Ligularia virgaurea,Aster alpinum,Leontopodium nanum and Elymus nutans that reproduce by seeds develop rapidly due to change of soil micro-environment. Species diversity ranked as medium degraded grassland(3.41) severely degraded grassland(3.39)light degraded grassland(2.99).Evenness index ranked as severely degraded grassland(0.94)medium degraded grassland(0.92) light degraded grassland(0.86).Aboveground biomass in medium degraded grassland ranked at the top,followed by light degraded grassland and severely degraded grassland.Grass and sedge biomass decreased and herb biomass increased with grassland degradation.Belowground biomass in light degraded grassland is higher than in severely degraded grassland.Soil water content in 0~20 cm profile in light degraded grassland is significant higher than that in severely degraded grassland(p0.01). Correlation analysis showed that there is a significant positive correlation between vegetation cover and soil water content.Soil water-retaining capacity increases with the increase of vegetation coverage.
Publication Year: 2006
Publication Date: 2006-01-01
Language: en
Type: article
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Cited By Count: 4
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