Study on the Biome Classification of Helophytes at Maqu Wetland

[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.

Variation and potential influence factors of foliar pH in land-water ecozones of three small plateau lakes

Aims Foliar pH of terrestrial plants,a trait tightly associated with plant physiology and nutrient utilization,varies with plant functional types(PFTs)and environmental changes.However,it is yet unclear about the variation in foliar pH of aquatic plants,and the difference between aquatic and terrestrial plants.Methods Foliar pH,leaf carbon,nitrogen content of plants along the lakeshore zones and the environmental conditions(water or soil pH,water status)of the corresponding vegetation of three small plateau lakes were investigated,to determine the variation and potential influence factors of foliar pH at both PFT and community levels.Important Findings Foliar pH varied largely among aquatic plants,and across aquatic,helophytic and terrestrial plants.Floating-leaved macrophytes had more acidic foliage(pH=4.21±0.05)than emergent(5.71±0.07)and submerged macrophytes(5.82±0.06).Foliar pH of aquatic herbs(5.43±0.10)was lower than that of helophytic(6.12±0.07)and terrestrial herbs(5.74±0.05).Terrestrial herbs had significantly higher foliar pH than woody plants.The variation in foliar pH across PFTs may be mainly ascribed to leaf structure,light utilization and nutrient characteristics.Consistent with the pattern on PFT level,aquatic communities had more acidic foliage than terrestrial communities,which was mainly shaped by species composition,water status and environmental pH.This study documented the first-time foliar pH of aquatic plants,and comparison of foliar pH among various plant types at a landscape scale.Our results provide bases for further exploration of the underlying mechanism and its ecological significance for wetland ecosystems.