| The national nature reserve of Ruoergai plateau wetland is a unique type of alpine-cold of peat swamp in global, also is a concentrated distribution area of peat swamp in China. Situated in the eastern edge of Qinghai-Tibet Plateau and in the upper reaches of yellow river, these natural wetlands play a critical role in regulation of water levels for the lower reaches of these rivers through several processes including converging the runoff of rainfall, melted snow and ice, managing flood. By the environment area of distinctive climate and unique geographic location, it has bred an alpine region with living the valuable-rare animals and plant in the word. On the other hand, the wetland of Ruoergai, where is the minorities live region, also as a nomadic area and well-know tourist area, is the important area basis for local social stability, economic development, also is most prominent areas of conflict which biodiversity conservation and protection of wetland resources fight with wetland resources using. Wetland nature reserve of Ruoergai landscape changes are not only changed its landscape spatial structure, but also impact the original ecosystem services of this wetland. In particular, biodiversity habitats have an important impact. The researches in Ruoergai wetland show: water environment area was reducing year by year, and the heart area of wetland transferred, wetland environments Suitable for a variety of rare animals and plants lived and propagated were losing, biodiversity conservation was badly threatened and the local sustainable development of animal husbandry was compromised. These wetland places became the focus of attention at home and abroad, but for a long time researches in Ruoergai wetland are elementary in China's scientific community.In this paper, Ruoergai wetland national nature reserve was selected as a research area. The principle of landscape ecology and 3S technologies was used as a basic guide. From 1990 to 2007, the landscape changes of Ruoergai wetland national nature reserve are analyzed, the wetland landscape changes of major or critical driving forces are discussed. The found results will use to control the reserve people economic activity and direct reasonably sustainable wetland resources use, to provide the scientific and effective protection reserve management, and also will help someone to make reserve management policies, to response global climate change, to maintain a sustainable use of plateau wetland resources, restoration ecology, to maintain of ecological safety and sustainable social and economic development of the Yellow River basin. This study will make up for the weak areas of plateau wetland research.Based on the 3S-technique, and by using the Fragstats software and combining with related historical data, survey data and sampling experiment, the variation of the landscape patterns of the plateau wetland reserve in the interpretation images(TM) of the years of 1990 and 2000 and 2007 were analyzed quantitatively. The results show that: Over these 18 years, the evolution of wetland landscape components was degraded marsh as the main advantages of type, from 45.36% increase to 48.05%, which forms the landscape matrix; in landscape level, diversity index, landscape fragmentation increased within the latest period of time, so did the patch numbers, from 2000 to 2007 the net gains were 27, and Landscape edge density increased to 0.626m/ hm2 within 2007, from 2000 to 2007 Shannon diversity index was 1.2769 to 1.2797; in class level, grass and degraded-marsh patch fragmentation, spatial heterogeneity degree were the highest, which in the period of time were increasing because of drainage, frequent and long grazing influence, but lake was the lowest; in temporal evolution of landscape spatial, water habitat areas were decrease, grassland(degraded-marsh and grass) area continued to grow, degraded-marsh and grass area respectively increased 1978.60hm2, 2559.09 hm2 from 1990 to 2000, water area was still shrinking and grazing area keep funding from 2000 to 2007, sand area recently increased 1945.90 hm2 in the term. This reflected the gradual evolution changes, from native wetland landscape to grazing pasture land in Ruoergai wetland landscape.Papers analysis showed out the key factor of Ruoergai wetland landscape change, under the climate warming conditions, the community population in this reserve were growing, it caused people survival needs stress to drainage and over or high-strength grazing, which accelerated the grass and degraded-marsh degradation, add the recovery of the desertification of the grass being trampled and again grazing, that caused desertification trends exacerbate in short term, rodents spread; in addition, economic development activities such as road construction, urbanization and mining activities, as well as on the resources of the high strength dependence and the impact of rapid economic development, raised out of order messages for tourism and which out of mining medicinal interference, droved the wetland degradation. After 14 years of Ruoergai reserve authority actively managed, the landscape fragmentation of landscape-scale was overall downward and the landscape conglomeration of landscape-scale was increment, a small increase in rivers, wetlands environmental improvement. Preserve wetland management had played a positive role, but wetland marsh degradation to grass pasture succession was the remains of this period of major trends. Strengthening the control of people in the area of economic activity is the reserve authority management base for implement wetland biodiversity conservation and sustainable use of wetland resources. For treatment and recovery Ruoergai wetland, must improve the Ruoergai wetlands protection awareness, thought over the landscape-scale of Ruoergai national nature reserve of the conservation and management, which can prevent wetland degradation to dealing with global climate changes. |
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