Research On The Vegetation Restoration Of Enclosure Grassland In Semi Desert Area

Yanchi County of Ningxia is located in semi desert area, is transition region of grassland and desert, with fragile ecosystem. This article applies the ecology theory and method, from the views of characteristic value, species diversity and niche, analyzes vegetation composition of artificial enclosure and the effect of enclosure on the vegetation recovery, at the same time, compares plant growth of different rainfall conditions and enclosure modes, and then gets the following conclusion:1) Liuyangbao artificial fencing vegetation is dominated by perennial grasses, with dry and semi dry water eco-form, and complete enclosure with the highest degree of vegetation biochemical. Most plant palatability is poorer, but plant palatability of half enclosure is relatively good. The vegetation coverage and biomass is the highest in semi enclosed region, second in the contest area, lowest in complete enclosure. From fluctuation strength, vegetation growth in2007,2010and2011is in good condition, with positive fluctuation, which in2007is the best.The vegetation growth in2008and2009is not in good condition, with fluctuation intensity less than0, which in2008is the worst. In complete enclosue xeric and strong xeric vegetation have the biggest niche breadth, and in semi enclosure and contrast area semi xeric vegetation are dominant species, because of the complete enclosure for long time, xeric and strong xeric vegetation gradually become the dominant species, and is not conducive to the construction of grassland in semi desert area. It is apparent absence of correlation between niche breadth and overlap. The overall level of niche overlap in half enclosure is not high, which showes that the scramble for resources between the species is relatively flat, the limited resources can be utilized effectively.2)3-5monthly rainfall is the main factors for influence of semi desert vegetation growth, vegetation coverage, biomass and fluctuations intensity and3-5monthly rainfall is generally positively correlated. Based on comparison of vegetation restoration among the complete enclosure, half enclosure and contrast area, effective moderate disturbance is beneficial to vegetation restoration and succession, which conform to the intermediate disturbance hypothesis, long-term fencing is a waste of resource of grassland.3)The local government is proposed to make overall planning for the protection of ecological environment, strengthen the vegetation protection, vigorously promote the policy of enclosure and grazing prohibition, create good exterior condition for ecological restoration, at the same time, strengthen the publicity education, training local people’s awareness of environmental protection.