Study on the Landcover Changes Based on GIS and RS Technologies: A Case Study of the Sanjiangyuan National Nature Reserve in the Hinterland Tibet Plateau, China

With global warming and increased human activity, more and more ground surface areas have been affected, which leads to the creation of many problems. To understand the ecological environment changes in a typical alpine region, information on landcovers changes in the study area from 2000 to 2020 was obtained by combining remote sensing, geographic information system, and traditional statistical analysis for the Sanjiangyuan National Nature Reserve on the Qinghai-Tibet Plateau, China. The results show that the changes of surface cover in Sanjiangyuan National Nature Reserve are relatively concentrated, mainly distributed in the sections of south, northwest, central, and northeast, with the area of the changed regions and the unchanged regions being 31,127.45 km2 and 271,941.37 km2, respectively. The transformation between the various types of ground landcover is mainly characterized by a shift from other types to grassland and from grassland to bare land. And the regions of change are mostly concentrated between 3500 - 4600 m in elevation.

Assessing Threats and Setting Conservation Priorities for Plant Species between Forest and Meadow Ecotone in Sanjiangyuan Nature Reserve, China

In order to understand the pattern and status of plant species in the forest-meadow ecotonein Sanjiangyuan Nature Reserve, this study was undertaken through expert consultation, literaturesurvey and fieldwork in various parts of the ecotone during 2002-2004. Based on 3 important systems,i.e. threatened status, genetic loss effect and use value, the list of threatened and prioritized plants wasestablished. In this paper, the threatened coefficient was defined as the criteria of category for threatenedplants, the conservation priorities coefficient summed by threatened coefficient, genetic coefficient anduse value coefficient was defined as the criteria of prioritized plants. In addition, 10 indicators toevaluate threatened grading and conservation priorities sequence were included in the 3 importantsystems. The weights of 3 systems and 10 indicators were given through expert consultation andanalytic hierarchy process. Ten indicators were given scores based on the subcriteria, respectively, andall the scores of the 3 systems were summed up for each species, then contrasted to the criteria ofthreatened grading and conservation priorities for plant species. The status of endangerment andconservation priorities of plant species were analyzed, and the results showed that the number ofendangered species was 2, vulnerable species 37, near threatened species 140, safe species 767; the firstconcern category had 4 species, the second concern category 18, the third concern category 150 and theleast concern category 774.

Three new species of eriophyoid mites from Maixiu National Forest Park,Qinghai Province,China(Acari:Eriophyoidea)

Three new species,Phyllocoptes angustais sp.nov.infesting Sibiraea angustata(Rehd.)Hand.-Mazz.(Rosaceae),Aculops brevifolis sp.nov.infesting Caragana brevifolia Kom.(Leguminosae),and Diptacus acutifolius sp.nov.infesting Cotoneaster acutifolius Turcz.(Rosaceae),are described and illustrated.All mites are collected from Maixiu National Forest Park,Zeku County,Huangnan Tibetan Autonomous Prefecture,Qinghai Province,China and are vagrant on the undersurfaces of leaves of their host plants.