Distribution Characteristics of Vegetation Among Different Ditches in the Hilly Area of Sichuan Basin

Vegetation is an important component of the ditch system and plays an important role for maintaining the ecological function of ditches. In order to protect biodiversity of ditch plants in the upper Yangtze River, different kinds of natural ditches in the hilly area of the Sichuan Basin were investigated by plant sampling method. Plant species, species diversity index, vegetation coverage and aboveground biomass in the different ditches were measured, and the influence of surrounding land use on the vegetation distribution of the ditches was further discussed. Results show that:(1) About 16 families and 20 species were measured in the natural ditches in the hilly area of the central Sichuan Basin. However, there were few dominant species, such as the highly invasive species Phyla nodiflora and Alternanthera philoxeroides, whose frequencies were 46.09% and 38.26%, respectively. Thus, the distribution of ditch vegetation in the hilly area of Sichuan Basin was not favorable. (2) The species in residential area ditches were relatively single and the community structure was relatively simple according to the assessment of biodiversity, while the plant species and the community structure of ditches was relatively complex in dry cropland, paddy field, and uncultivated land ditches. (3) Vegetation coverage and biomass in different ditches were significantly different. The average vegetation coverage in different ditches is in the order of paddy field > residential area > dry cropland > uncultivated land. The average vegetation biomass in different ditches is in the order of residential area > paddy field > dry cropland > uncultivated land.