Effects Of Enclosure On Soil And Vegetation Characteristics In The Agricultural-pastoral Ecotones Of Northern China

Yanchi located in the ecotone of the North China, is a transitional region linked to the steppe and desert, which belongs to the typical ecological fragile areas. Agro -Pastoral Ecotones in northern staggered with vegetation degradation and restoration is an important method in the study of global ecological transformation, has important ecological significance and practical significance. I collected ecological data from sites in Yanchi County, Liu Yang Bao during the period 2010-2015. years basis and theoretical investigation of Specifically, the characteristics and dynamics of vegetation and soil were assessed along with calculations of biological diversity (richness index, diversity index, dominance index and evenness index, as well as niche breadth and niche overlap index). Respectively to three different sealing enclosure region, that is completely sealed enclosure region, seasonal sealed enclosure and non exclusion zone is calculated and analyzed, through the study of artificial fencing measures of grassland vegetation restoration of in-depth, draw the following conclusions:1) In three different exclusion measures, soil moisture storage had significant differences (P<0.05), and non-closed enclosure area> seasonal enclosure area> complete enclosure area; the soil compaction has significant difference (P<0.05), and complete enclosure area> seasonal enclosure area> non-closed enclosure area; soil crust coverage has significant difference (P<0.05), complete enclosure area> seasonal enclosure area> non-closed enclosure area, soil crust cover and soil compaction degree was positively correlated and the common development of the role of soil moisture, the two common influence soil moisture spatial and temporal differences in the distribution, soil crust cover and compaction were negatively correlated with soil water content. The results prove that fenced enclosures is an effective means of grassland vegetation restoration, leading to an enhancement of the vegetation biomass. However, with the increase of the age of the closure, the closure of vegetation inhibited the growth of vegetation.2) In three different exclusion measures, species richness seasonal enclosure> complete enclosure> non-closed enclosed area, species diversity index seasonal enclosure> complete enclosure> non-closed enclosed area, which means that the fencing measures increase vegetation types, improve the biological diversity of species; Ecological dominance and evenness showed seasonal enclosure> non-closed enclosed> complete enclosure, which means of closure area makes more advantages, more uniform in grassland vegetation.3) Artificial fencing area niche study results show that, completely enclosure area gave advantage to the dominant species; the seasonal closure area of dominant species distribution is average; under a year-long common-use grazing regime (non-enclosure) there no single dominant species. Therefore, from the data on niche width we can see that, fencing measures can protect the dominant species in the grassland. But in the long run, fencing will result in inhibition of the growth of other species of sub-dominant species. The niche overlap results showed that the niche breadth and overlap between had no obvious linear relationship.