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Land use and land cover change and its driving forces in maqu county, China in the past 25 years

Research in Cold and Arid Regions 2016年第5期8卷 432-440页

作者： JunFeng Lu ZhiBao Dong GuangYin Hu WenJin Li WanYin Luo MingLiang Tan Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences State Key Laboratory of Grassland Agroecosystems School of Life Sciences Lanzhou University

maqu county is located in the northeast Qinghai-Tibetan Plateau, and it is the main watershed for the Yellow River. The ecosystem there is extremely vulnerable and sensitive to climate change and human activities, which have caused significant deterioration of the eco-environment in this region. In order to restore the ecological environment, a government project to restore the grazing areas to grassland was implemented in maqu county in early 2004. This study evaluates the effects of that restoration project on land use and land cover change （LUCC）, and explores the driving forces of LUCC in maqu county. In the study we used Landsat images obtained in 1989, 2004, 2009, and 2014 to establish databases of land use and land cover. Then we derived LUCC information by overlaying these layers using GIS software. Finally, we analyzed the main forces responsible for LUCC. The results showed that forests, high-coverage grasslands, and marshes experienced the most significant decreases during 1989–2004, by 882.8 ha, 35,250.4 ha, and 2,753.4 ha, respectively. However, moderate- and low-coverage grasslands and sand lands showed the opposite trend, increasing by 12,529.7 ha, 25,491.0 ha, and 577.5 ha, respectively. LUCC in 2004–2009 showed that ecological degradation slowed compared with 1989？2004. During 2009–2014, high- and moderate-coverage grasslands increased obviously, but low-coverage grasslands, marshes, unused lands, sand lands, and water areas showed the opposite trend. These results suggested that the degradation of the eco-environment was obvious before 2009, showing a decrease in the forests, grasslands, and water areas, and an increase in unused lands. The ecological degradation was reversed after 2009, as was mainly evidenced by increases in high- and mod-erate-coverage grasslands, and the shrinkage rate of marshes decreased obviously. These results showed that the project of restoring grazing lands to grassland had a positive effect on the LUCC. Other major fac

关键词： LUCC driving forces maqu county source region of the Yellow River

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Study on the Biome Classification of Helophytes at maqu Wetland

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Agricultural Science & Technology 2012年第10期13卷 2202-2205页

作者：张怀山赵桂琴张吉宇甘肃农业大学草业学院甘肃兰州730070 中国农业科学院兰州畜牧与兽药研究所甘肃兰州730050 兰州大学草地农业科技学院甘肃兰州730000

[Objective] This study aimed to accomplish a biome classification of helophytes at maqu,the first bend of the Yellow River.[Method] Helophgtes in the maqu wetland were investigated using quadrat sampling method with references to plant specimens.[Result] The helophyte communities at maqu wetland could be divided into two categories：sedge marshes and non-sedge marshes,which can be further subdivided into 4 *** constructive species mainly included Blysmus sinocompressus,Blysmocarex nudicarpa,Eleocharis valleculosa and Polygonum *** sub-constructive species consisted mainly of Carex brunnescens,Catabrosa aquatica,Kobresia kansuensis,Polygonum amphibium and Leontopodium *** total coverage of communities ranged from 5% to 90%,which were commonly found in areas permanently ponded with water,such as watercourse depressions,floodplains,valley depressions,terrace scarp depressions and riverhead depressions,with the underground water depth of 20-30 cm.[Conclusion] The biome classification of helophyte communities provided scientific basis for the ecological restoration and control of maqu wetland prairie.

关键词： Wetland Helophytes Biome classification maqu county

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