Changes in soil nutrients and the plant communitywith different stocking rates on steppe after rest grazing
Inner Mongolia Steppe, an important part of Eurasia Steppe, is not only the foundation of regional development, but also the important environmental barrier. According to the correlativity between soil nutrients and plant community, the paper studies the properties of soil nutrients and plant community during rest grazing. The results indicate: After 4-year rest grazing, as the conditions of maintaining the evenness of spatial pattern of soil nutrients and vegetation disappeared, the spatial heterogeneity of soil nutrients increased, and the ratio of random factors went up. Spatial heterogeneity of soil organic C, total N, inorganic N, available P and S is the largest for 0.00sheep/hm2, and the smallest for 4.00sheep/hm2. Biomass and coverage of plant community increased after 4-year rest grazing, but no significance for plant community coverage (P>0.05), there was significant difference (P<0.05) for plant community biomass compared with 1998 (except 0.00sheep/hm2). Compared with 1.33sheep/hm2, 4.00sheep/hm2 and 6.67sheep/hm2, preponderant plants of 0.00sheep/hm2 have a diversified trend. Bushiness of plant community was correlated with stocking rate and succession sequence, the smaller the stocking rate and the longer the succession sequence, the more significant the bushiness. After 4-year rest grazing, annual plants, Leymus chinensis, Stipa krylovii, Kochia prostrate, Artemisia frigida (except 6.67 sheep/hm2) and Melissitus ruthenica (except 0.00sheep/hm2) increased, but Potentilla acaulis decreased. Diversity indices and evenness indices of plant species declined during rest grazing, which means that species diversity increased and evenness declined. Biomass, height, coverage and diversity of plant community have positive correlations with soil nutrients distribution, but only significant between biomass, height and soil organic C, total N, inorganic N, available P and S (PO.05). In Inner Mongolia Steppe, because of the comprehensive effects of plant properties, soil pH, organic carbon, total N, inorganic N and N mineralisation of different plant population patches have different variations. Soil pH and total nitrogen content of Leymus chinensis patch is the highest of different plant population patches, and then Potentilla acaulis patch, Caragana microphylla patch is the lowest. Except between Artemisia frigida and Kochia prostrata patches, there are significant differences (P<0.05) between other plant population patches. Soil inorganic nitrogen content of Leymus chinensis patch is the highest, and then Artemisia frigida, Caragana microphylla, Kochia prostrata and Potentilla acaulis patches respectively. Soil inorganic nitrogen content has significant differences (P<0.05) between all the different plant population patches. Soil microbial biomass nitrogen of Caragana microphylla patch is the highest, and then Leymus chinensis, Artemisia frigida, Kochia prostrata and Potentilla acaulis patches respectively. Soil microbial biomass nitrogen has significant differences (P<0.05) between all the different plant population patches. Soil net N mineralisation rate of Leymus chinensis patch is the highest of different plant population patches, and then Artemisia frigida, Potentilla acaulis, Kochia prostrata and Caragana microphylla patches respectively, and there are significant differences (P<0.05) between all the different plant population patches. There are significant (P<0.05) positive correlativity between soil net N mineralisation rate and soil pH and temperature, and significant (P<0.05) negative correlativity between soil net N mineralisation rate and soil C.N. Soil organic carbon content of Caragana microphylla patch is the highest, and then Leymus chinensis patch, and Potentilla acaulis patch is the lowest. Except between Artemisia frigida and Kochia prostrata patches, there are significant differences (P<0.05) for soil organic carbon between other plant population patches.
Liu Zhongkuan Han Jianguo Wang Sniping Chen Zuozhong
Institute of Grassland Science, China Agricultural University, Beijing 100094 Laboratory of Quantita Institute of Grassland Science, China Agricultural University, Beijing 100094 Laboratory of Quantitative Vegetation Ecology, Institute of Botany, Chinese Academy of Sciences, Bei
国际会议
The Workshop of Sustainable Grassland Management in China and Australia(中国--澳大利亚可持续性草地管理研讨会)
乌鲁木齐
英文
127-128
2011-08-01（万方平台首次上网日期，不代表论文的发表时间）