The Ecological Response Of Typical Wetland Vegetation To Water Regimes In The Sangjiang Plain

The Honghe National Nature Reserve in the Sanjiang Plain is characterized by the rich biodiversity and important ecological functions. Therefore, the typical wetland vegetation in Honghe National Nature Reserve were selected to be the research objects in current study, to reveal the coupling relationship between ecological characteristics of wetland vegetation and water regime, and further illuminate spatial distribution of vegetation and the physiological in different the wetland water conditions. The main conclusions were listed as follows:1. The wetland vegetation was classified into 8 associations by the TWINSPAN, The associations are as follows: Assoc. Carex lasiocarpa—Carex pseudo-curaica; Assoc. Carex lasiocarpa—Glyceria spiculosa—Carex pseudo-curaica; Assoc. Carex pseudo-curaica—Carex lasiocarpa—Glyceria spiculosa + Phragmites australis; Assoc. Carex pseudo-curaica—Glyceria spiculosa—Calamagrostis angustifolia; Assoc. Glyceria spiculosa—Carex humida—Calamagrostis angustifolia; Assoc. Calamagrostis angustifolia—Carex humida—Carex lasiocarpa; Assoc. Calamagrostis angustifolia—Carex humida + Spiraea salicifolia; and Assoc. Anemone dichotoma+Calamagrostis angustifolia. The DCA ordination of dominant species was similar to that of associations, which indicated the community type was determined by the distribution pattern of the species in the communities, to some extent.2. Water gradients of the maximum stem length of Calamagrostis angustifolia, Carex lasiocarpa, Carex pseudo-curaica, Glyceria spiculosa were, 0.40, 0.50, 0.60 and 0.55, respectively. The maximum densities were, 0.36, 0.40, 0.55 and 0.50, respectively. The maximum aboveground biomass were, 0.38, 0.42, 0.50 and 0.50, respectively.3. The characteristics of wetland vegetation species diversity were analyzed, the results showed that altitude range and climate conditions were relatively consistent in the research area, so that habitat differences are the main factor controlling species diversity of wetland vegetation in the Sanjiang Plain.4. According to variation of the water regime in recent 50 years in Honghe National Nature Reserve, the water level, region inundation area and storage capacity has decreased significantly, in 2012, the water level has decreased 1.01 m, inundation area 79.6km2, storage capacity 0.79×108m3 compared with those in 1962. Therefore, based on the results in current study, the changes of the hydrological regime will exert a significant influence on the vegetation type and distribution in wetlands.