[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 biomes.The constructive species mainly included Blysmus sinocompressus,Blysmocarex nudicarpa,Eleocharis valleculosa and Polygonum amphibian.The sub-constructive species consisted mainly of Carex brunnescens,Catabrosa aquatica,Kobresia kansuensis,Polygonum amphibium and Leontopodium alpinum.The 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.
[Objective] This study was to reveal the correlation between leaf area and drought resistance in different varieties of alfalfa.[Method] Using various alfalfa varieties as experimental materials,the drought resistance of leaves of drought-stressed alfalfa plants was assessed by measuring the content of free proline for analyzing its correlation with leaf area.[Result] Under drought condition,the drought resistance of alfalfa is directly related to leaf area in a positive correlation.[Conclusion] Leaf area could be used as an institutional assistant index to reflect the resistance of different alfalfa varieties.
