节点文献
若尔盖高原湿地国家级自然保护区景观格局变化及驱动力
The Changes of Landscape and Its Driving Forces in Ruo’ Ergai Plateau National Wetland Reserve in Sichuan, China
【作者】 邓茂林;
【导师】 田昆;
【作者基本信息】 西南林业大学 , 生态学, 2010, 硕士
【摘要】 若尔盖高原湿地国家级自然保护区是全球类型独特的高寒泥炭沼泽湿地,为我国泥炭沼泽的集中分布区。地处青藏高原东缘的黄河上游,通过湿地汇集降雨和地表径流、冰川融雪,以及调控洪水等过程,对下游水量均衡起到重要作用。独特的气候环境与地理区位,孕育了世界高山带珍稀动、植物的生存环境,另一方面,若尔盖保护区地处少数民族地区,又是藏民游牧区和著名旅游区,是当地社会稳定、经济发展的重要基础,也是生物多样性保护与湿地资源保护、利用矛盾极为突出的地区。若尔盖保护区湿地景观变化不仅改变了其景观的空间结构,而且影响了湿地景观的原有生态服务功能,尤其对生物多样性的栖息生境产生重要影响。该区域已有的研究表明,保护区水环境逐年减少,湿地质心迁移,适宜多种珍稀动、植物生存繁衍的湿地环境不断丧失,生物多样性受到严重威胁并危及到当地经济的可持续发展,从而成为国内外广泛关注的焦点。但长期以来国内外对这一湿地的研究并不深入。论文选取若尔盖高原湿地国家级自然保护区,以景观生态学基本原理为指导,结合3S技术,客观分析若尔盖国家级自然保护区湿地18年(1990~2007)来景观格局的动态变化,探讨湿地景观格局变化的主要或关键驱动力,为控制保护区人类经济活动且合理地持续利用湿地资源,为保护区有效保护管理提供科学依据,指导保护区管理政策制定来应对全球气候环境变化,保护受损高原湿地的珍稀动植物资源,恢复其受损生境,维护黄河流域的生态安全和经济社会可持续发展。本研究基于遥感、地理信息系统和全球定位系统等技术手段对若尔盖高原湿地进行景观格局变化研究。选择了该区域1990年、2000年、2007年时相较为接近的三幅影像为基本数据源进行景观解译,结合相关历史资料、调查数据和采样实验,利用景观分析软件Fragstats3.3计算景观格局指数,统计其变化特征。结果表明,18年来,湿地景观组分演变以沼泽化草甸为主要优势类型,面积从45.36%增加至48.05%,成为景观基底。景观尺度下,多样性指数、景观破碎程度增加,斑块数目2000年到2007年净增27,景观边缘密度2007年增加0.626m/ hm2,Shannon多样性指数由2000年的1.2769至2007年增加到1.2797。斑块水平中,草甸与沼泽化草甸斑块破碎程度、空间异质程度最高,湖泊最低。在排水、人为放牧干扰的长期频繁影响下,沼泽化草甸、草甸破碎程度、空间异质程度升高。景观时空不断演化,有水的生境面积减少,而沼泽化草甸、干草甸(草场)面积持续增加,1990~2000年,沼泽化草甸、草甸面积分别增加了1978.60 hm2和2559.09 hm2,2000 ~2007年,湖沼水面积仍在萎缩,草场放牧面积保持增长,沙地短期增加1945.90 hm2,反映了若尔盖湿地景观由原生湿地景观逐渐往陆生草场的变化过程。论文研究分析获得了若尔盖湿地景观格局变化的关键驱动因子,其在气候变暖自然条件下,保护区社区人口增涨,生存需求胁迫下对湿地排干、超载或高强度放牧引起或加速了沼泽和沼泽化草甸退化,导致草甸沙化;恢复中的沙化草地遭受再次放牧践踏,沙化趋势加剧,鼠害泛滥;另外,经济开发活动如道路建设、城镇化和采矿活动,以及对资源高强度依赖和经济快速发展的冲击,引发的无序旅游及滥挖乱采药材等干扰,驱动着湿地退化。14年来若尔盖在保护区管理局多年的积极管理下,景观尺度总体上破碎程度呈下降趋势,景观聚集度递增,河流小幅增加,湿地环境有所改善,保护区保护管理起到了积极作用,但沼泽湿地向草地牧场退化演替仍是这一时期的主要趋势。加强控制该区人类经济活动,是保护区管理局实现湿地生物多样性保护与湿地资源可持续利用的管理基础,对若尔盖退化湿地进行治理和恢复,须提高对若尔盖高原湿地保护的认识,从景观大尺度上思考若尔盖国家级自然保护区的保护管理,提出应对全球气候变化的湿地保护策略。
【Abstract】 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.
【Key words】 Ruoergai Plateau Wetland; Nature Reserve; Landscape Changes; 3S technology; Driving Force;