Study On The Plant Community Diversity And Vegetation Coverage Changes In The South Of Gurbantunggut Desert

Taking field survey data, the CEBERS data of year 2001, 2005, 2008 as the information sources; taking the Restoration Ecology, the vegetation ecology as the theoretical basis; taking the south rim of Gurbantunggut as research area, using the statistical method and the remote sensing and geography information technology, has analyzed the multiple characteristics of plant community in the research area, evaluated the vegetation degree of coverage and researched the area degree of vegetation coverage changes in 2001-2008. The main results showed:There are six kinds of plant communities in total. The community multiplicity from low in turn are Erodium oxyrrhynchum community, Ceratocarpus arenarius community, Carex physodes community, the Calligonum mongolicum community, the Reaumuria soongorica community, and the Reaumuria soongorica community. On the whole, since the moisture content conditions in the research area are basically similar, the species multiple differences of the plant community are not big.Among them, the multiplicity and abundance of herb community are bigger than the bush community, while the dominance is lower.From the earthen mound between to the sand dune on, the parameter of the plant multiplicity advances gradually, Changes among community multiplicity of the north and south towards plant, dominance and degree of coverage are not big, the landform shape differences of extends in the direction with the sand dune are not remarkable. They are in certain corresponding relations.The distributed rule of plant community in research area are: The Calligonum mongolicum scattered fragmentarily in the north and south towards of the leeward slope in the earthen mound slope and the summit, In fact directly the seed seedling are survival in half fixed sand dune against the wind slope. The Reaumuria soongorica distributes in the east and west towards of the sand dune between the earthen mound the flat land, there is nothing in the summit. Because the specificity of growing of the Ceratocarpus (ground, underground all can solid), the compatibility is strong, it can grow in different towards of the sand dune in the north and south on each slope position. Carex physodes distributes both in the earthen mound and various slope faces, and it grows more densely in the earthen mound between. The Haloxylon ammodendron has strong compatibility to the desert adverse circumstance, it is the most widespread species in the research area.In view of the characteristic of QB and the CEBERS data, to estimate the two kinds of data to carry on the vegetation degree of coverage separately with different methods, the result indicate that, based on the QB data vegetation indices, ndvi method for regress model, dimidiate pixel model, improve dimidiate pixel model is 84.44%, 94.08%, 97.85%, the element dichotomy estimation effect is best. Based on the CEBERS data vegetation coverage estimation, take the QB element dichotomy estimate degree of cover as the true value, the vegetation exponential method, the return modeling, the element dichotomy, the improvement element dichotomy estimation precision respectively is 77.78%, 97.55%, 97.35% and 98.88%, the improvement element dichotomy simple, practical also is identical with the actual situation of fit, the precision is highest.Considering the comprehensive factores vegetation coverage estimation precision, cost and data are whether easy to be obtained and so on, when carries on the wide range and long time vegetation coverage changing analysis, the best project is based on the CEBERS data element dichotomy plan.Based on the CEBERS data, to analyze the vegetation degree of coverage changing of research in 2001-2008 with the element dichotomy, the result indicates that, the research area vegetation coverage reduces in 2001-2005, the degree of coverage on 42750hm2 in 0.2 above shifted to 0.2 below; in 2005-2008, vegetation degree of coverage 10860hm2 in 0.2 below transform to 0.2 above. The implementation of national key public welfare forest protection project and the railing seal nurture are reasons which the vegetation restores.