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Biomass and species diversity of herbosa at different position and aspects of slope in the Hilly-gully Region of Loess Plateau |
Zhou Ping1,2,Liu Guobin1,Hou Xilu1 |
1.Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Northwest A&F University,712100,Yangling,Shaanxi;2.Graduate University of Chinese Academy of Sciences,100049,Beijing: China |
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Abstract Based on the investigation of herbasa of different positions and aspects of slope in the Dafanjiagou and Guaigou of Zhifanggou watershed on the Loess Plateau,the indices of coverage,above-ground biomass and species diversity were analyzed.The results showed that the number of species reach to twenty in the shady slope,thirty percent more than that of sunny slope.The biomass and coverage of herbosa is decreasing from upper slope to the lower slope both on the sunny and shady slope.The shrubs appears in the batter condition with more water and nutrients.Margalef and Menhinick richness indices are decreasing with slope position raising in the sunny slope,while Mafgalef index in the shady slope has the same law,but Menhinick index in the shady slope is increasing with slope position raising.The three eveness indices and biodiversity indices are all decreasing with raising of slope position.There are significant difference among herbosa coverage,Margalef and Alatalo indices of different slope positions(P<0.05).Meanwhile,there are also significant positive correlation between slope position and Margalef index,Alatalo index(P<0.05),also extremely significant positive correlation between slope position and Shannon-wiener index(P<0.01).In order to avoid one sidedness causing by using signal index,it would be better to choose more biodiversity indices to describe or evaluate diversity,richness or evenness of herbosa in practice.Mastering the characters of herbosa,its habitats and recognizing succession condition and discipline are very important for guiding the ecosystem restoration.
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Received: 28 February 2008
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