Study On The Response Of Wetland Ecological Environment Quality To Community Land Use Change In Qomolangma National Nature Reserve

Wetland is natural complexes formed by the interaction between water and land,and wetland ecosystems are of great strategic value for maintaining biodiversity,promoting the sustainable livelihood of farmers and herdsmen,coping with climate change and ensuring national ecological security.Alpine wetland is significant for both maintaining biodiversity and supporting human development in the plateau region,and has a more important ecological and socio-economic value.There is rich wetland resource in Qomolangma National Nature Reserve(QNNR)of Qinghai-Tibet Plateau,and the livelihood of 106,000 farmers and herdsmen in QNNR heavily rely on wetland resources.Land use activities in QNNR produced continuous impact to ecological environment especially that of the wetland,as well as a great pressure to the ecological protection of wetlands in the nature reserve.Therefore,to analyse the change of wetland ecological environment quality of QNNR and the land-use change at community level,and to explore the response mechanism of wetland ecological environment quality to the land-use change of the community,is not only the basic work of exploring the impact of human activities on the ecological environment of wetland,but also a powerful impetus of realizing ecological protection and sustainable development of farmers and herdsmen.This thesis systematically analyzed the wetland of QNNR at both nature reserver level and community level.According to the research mainline of ‘Wetland thematic information extraction and wetland spatiotemporal change → Wetland ecological environment quality assessment and spatiotemporal change → Community land use and its change → Response of wetland ecological environment quality to community land-use change’,the conclusions were as follows:(1)The spatial-temporal distribution and change of wetland.The total wetland area of QNNR was about 820 square kilometers in 2018 with annual fluctuation,and the spatial distribution of marsh wetlands,rivers,and lakes was balanced.In which,there was significant increase of wetland area in Pengqu watershed and Dingjie Wetland;while notable decrease in Pekucuo-Xixiabangma area,Jiangga Wetland and Pengqu Big Bend.The wetland in QNNR presented scattered spatial distribution and relatively stable area.The locations of wetland with rapid area change were comparatively fixed.In which,the rapid area decreased wetland was concentrated in the southwest and east of QNNR,and significant area increased wetland distributed in the Pengqu watershed and DingjieWetland.(2)The quality and its changes of wetland ecological environment.The dominant quality level of wetland ecological environment in QNNR was poor and fair.During1988 to 2018,quality level distribution pattern from west to east was fair — very poor —poor,good — poor — poor,and good — fair — excellent.In which,the change of wetland ecological environment was gradually improving in the central region,and worsening followed improving in eastern and western regions.However,with the domination of significant improvement,wetland ecological environment quality change in QNNR also presented the characteristics of polarization,fragmentation,etc in some areas in the same period.(3)Community land use and its changes.During 1988 to 2018,the community land-use of QNNR was dominated by wetland pasture and grassland pasture.Agricultural cultivation,settlements,and roads had generally increased,and the influence of human activities on land was increasing.In detail,land use of high populated farming-husbandry mixed areas focused on agricultural development,the spatial land use indicators changed by planting and grazing behaviors;grazing activity in low populated farming-husbandry mixed areas kept strengthening,and the spatial land use indicators were more affected by planting behaviors;frequently mixed grazing was land use characteristic in husbandry-relatively open areas,and spatial land use indicators corresponded to seasonal grazing activities in wetland;grazing heavily depended on wetland pasture in husbandry-relatively closed areas,and spatial land use indicators were significantly influenced by grazing distance.(4)Response mechanism of the wetland ecological environment quality to the community land use change.The response mechanism of the wetland ecological environment quality to the community land use change were as follows:First,at QNNR level,the wetland ecological environment quality increased with increasing of net income per capita in periodic fluctuations,decreased with increasing of livestock carrying quantity in weak cyclical fluctuations,and increased before decreasing with increasing of population carrying quantity.Second,from the perspective of spatial change,the quality of the wetland ecological environment in relatively low income zone or transition zone from higher to low income increased with increasing of net income per capita,thus the increase of net income per capita produced positive effect;the ecological environment quality of wetlands in areaswith extremely low livestock carrying quantity and transition areas decreased with increasing of livestock carrying quantity,thus the livestock carrying quantity produced negative effect;in the areas with high population carrying quantity,the wetland ecological environment quality decreased with increasing of population carrying quantity,thus population carrying quantity produced negative effect.Third,at community level,(1)in high populated farming-husbandry mixed areas,the impact of fertilizer input increase on ecological environment quality of wetland pasture had decreased;wetland ecological environment quality decreased with increasing of grazing intensity;and labor input had a greater impact on wetland ecological environment quality.(2)In low populated farming-husbandry mixed areas,the increase of chemical fertilizer input enlarged its affect on ecological environment quality of wetland pastures;ecological environment quality of wetland pastures had low sensitivity to high grazing intensity;the effect of labor input on ecological environment quality decreased progressively in the transition from plantation to pasture.(3)In husbandry-relatively open areas,ecological environment quality of wetland pastures had low sensitivity to high grazing intensity and high labor input intensity.(4)In husbandry-relatively closed areas,there were different levels of ecological environment quality sensitivity to grazing intensity in the hinterland and edge of the wetland;labor input had little effect on the quality of the wetland ecological environment.Based on above findings,this study analyzed the current challenges of wetland in protected areas,and proposed suggestions for sustainable use and ecological protection.At the QNNR level,strategies were proposed for wetland protection and management,monitoring and investigation,protection planning,ecological compensation,team building,and local publicity.At community level,suggestions for community participation in protection,community wetland zoning management planning,and eco-friendly community development were proposed.