| In recent years, the comprehensive effect of global warming, human activity increase, ecological environment deterioration and any other factors obviously lead to the degeneration of the grassland ecosystem degenerated and the increase of rodent damage. Although many scholars have curried out a lot of researches from different levels and angles on the rodent population regulation mechanism, the problems of rodent population outbreak and regulation mechanism were still difficult and hot issues to be resolved in the current ecology. They are very important to research the relationship between plants and rodents and their functions to rodent damage control under the conditions of global change and human activity increase in revealing the rodent population dynamics and rodents control. This experiment established a large fence system in the Inner Mongolia grassland, determined the changes of plant community structure, the content of organic matter and total nitrogen in the soil in the fence after the treatments of grazing, watering and adding food, confirmed the effect of global change and human activity increase on grassland ecological system, supplied the data for analysing the relationship between vegetation community structure changes and Brandt’s voles’ population, revealed the mechanism of population fluctuations and disaster of Brandt’s voles, to provided theory evidencethe for the damage control of the Brandt’s voles, and also set up the foundation for the effective management of grassland ecosystem. The results are as follows:1) The community structure of the vegetation was significantly changed under the activities of Brandt’s voles and grazing (P<0.05). The activity of Brandt’s voles and grazing both significantly decreased aboveground biomass, coverage, height and diversity of the vegetation (P<0.05). The interaction between them had significant effect on aboveground biomass, height and richness of the vegetation communities (P<0.05), but it had no significant effect on coverage and Shannon Weiner index (P>0.05).2) The community structure of the vegetation was significantly changed under the activities of Brandt’s voles and watering (P<0.05). The activities of Brandt’s voles significantly decreased aboveground biomass, coverage, height and diversity of the vegetation (P<0.05). Watering significantly increased coverage and diversity of the vegetation (P<0.05), but had no significant effect on aboveground biomass and height (P>0.05). The interaction between them had significant effect on aboveground biomass and coverage (P<0.05), but it had no significant effect on height (P>0.05).3) The community structure of the vegetation was significantly changed under the activities of Brandt’s voles and fooding increase (P<0.05). The activities of Brandt’s voles significantly decreased aboveground biomass, coverage, height and diversity of the vegetation (P<0.05); Fooding increase had no significant effect on the community structure of the vegetation (P>0.05); The interaction between them had significant effect on aboveground biomass, coverage, height and diversity of the vegetation (P<0.05).4) Under the treatment of Brandt’s voles and grazing, the total nitrogen contentd under 0-10cm and 10-20cm depth of the soil organic matter content and 0-10 cm depth of the soil for voles and moderate-grazing groups were significantly lower than those for no-voles and no-grazing control groups, voles groups, voles and light-grazing groups (P<1.05), but there was no significant difference on the soil organic matter and total nitrogen content among no-voles and no-grazing control groups, voles groups and voles and light-grazing groups (P>0.05). The soil total nitrogen content under 10-20cm depth for voles and moderate-grazing groups were significantly higher than that for no-voles and no-grazing control groups, voles groups, voles and light-grazing groups in 2013 (P<0.05), and for no-voles and no-grazing control groups were significantly lower than those for voles groups, voles and light-grazing groups, voles and moderate-grazing groups in 2014 (P< 0.05).5) Under the treatment of Brandt’s voles and watering, the soil organic matter contents under 0-10cm and 10-20cm depth of the soil and the total nitrogen content under 0-10 cm depth of the soil for no-voles and no-watering control groups, no-voles and light-watering groups, no-voles and moderate-watering groups were significantly higher than thase for voles groups, voles and light-watering groups, voles and moderate-watering groups (P<0.05). The total nitrogen contents under 10-20cm depth of the soil for voles groups, voles and light-watering groups, voles and moderate-watering groups were significantly higher than those for no-voles and no-watering control groups, no-voles and light-watering groups, no-voles and moderate-watering groups (P<0.05).6) Under the treatment of Brandt’s voles and fooding, the organic matter content under 0-10 cm depth of the soil was significantly lower than that for no-voles and no-fooding control groups, voles groups (P<0.05), but there was no significant difference under 10-20 cm depth of the soil for the organic matter content between no-voles and no-fooding control groups and voles groups (P>0.05). The total nitrogen contents udner 0-10cm depth of the soil for no-voles and no-fooding control groups, voles and fooding groups were both higher than those for voles groups (P<0.05). The soil total nitrogen contents for voles groups, voles and fooding groups were both significantly higher than those for novoles and nofooding control groups under 10-20cm depth of the soil (P<0.05).We concluded that grazing, watering and adding food would have a greater impact on vegetation community structure and soil physico-chemical properties in grassland, thus affected Brandt’s voles’ population regulation. Therefore, climate change and human activities increased will influence animale populations by affecting vegetation community structure and soil physico-chemical properties, and there may be certun interaction between them. |
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