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Study on the Vegetation Change of Sandy Grassland and the Effect of Fencing in Yanchi of Ningxia

Author: LiuJian
Tutor: ZhangKeBin
School: Beijing Forestry University
Course: Soil and Water Conservation and Desertification Combating
Keywords: Desertified grassland Plant diversity Fencing Niche Yanchi County
CLC: S812
Type: Master's thesis
Year: 2011
Downloads: 86
Quote: 1
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Abstract


Yanchi County is located in northern ecotone, fragile ecological environment, serious desertification of grassland. In order to understand the role of Yanchi County in recent years meters of grassland vegetation changes, as well as fencing measures of desertified grassland vegetation recovery on 6 different types of grassland in Yanchi County as the research object, combined with the theory of restoration ecology through field survey, their plant species composition, vegetation number of characteristics, community structure and fencing effect a more in-depth study of the following preliminary conclusions: (1) the amount of vegetation characteristics (cover, height, community density, biomass, etc.) reflect the size of the growth conditions of vegetation and grassland productivity. The period 2003-2010, the the 2003,2004,2009 vegetation growth conditions overall better grass higher productivity; 2005,2008 two years of vegetation growth condition overall poorer, less productive grasslands; community structure is community in all living organisms and their individual distributed in space and time on the state, mainly including physical appearance and biological components. Species diversity and community evenness, species richness indicators can reflect the overall level of the community structure. 2007 species richness index of Yanchi County, the diversity index is the highest over the years, community evenness index is relatively high. Show that in 2007 Yanchi County vegetation community structure is relatively stable. 2006 community evenness index, species diversity indices are the lowest in the calendar year, 2006 vegetation community structure is unreasonable. (2) under the influence of the different recovery measures, the vegetation changes: grassland restoration of cropland, fallow, Natural Vegetation restoration measures played a significant role of vegetation recovery. Enclosure on the species composition had a greater impact on the number of characteristics, structure, population niche. Comparative analysis of the three types of enclosed plots can be found, the fencing at the initial stage (lt; 8a) can indeed play a catalytic role in vegetation restoration, but with the increasing of enclosing life, but showed degradation of vegetation growth status trend. Visible, not enclosing life is the longer, the better the effect of vegetation restoration. The long enclosed time will lead to grassland and grassland vegetation to the development of drought and drought biochemical direction. For fencing grass in years (lt; 8a) and plowing to break the soil crust to promote the infiltration of precipitation. And plowing area and tillage depth should be appropriate, should not only conducive to the recovery of the vegetation, not to make violations of the soil caused by wind erosion. (4) precipitation Yanchi County vegetation growth status of natural factors, how much of the precipitation is strongly restricts the growth of vegetation. Unreasonable human economic activities seriously undermine the natural state of the vegetation, but through the implementation of the measures of grassland restoration of cropland and grazing, the vegetation coverage in Yanchi County was an increasing trend to curb the expansion of land desertification greatly promoting grassland construction.

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CLC: > Agricultural Sciences > Livestock, animal medicine,hunting,silkworm,bee > General Animal Science > Grassland Science,prairie school
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