Distribution of Aquatic Macrophytes in the Huaihe River Basin and Causes

In order to explore community characteristics and distribution of aquatic macrophytes in the Henan section of Huaihe River Basin and causes, field survey in addition to in-laboratory analysis was carried out of composition of aquatic macrophytes, and characteristics of the water and the soil environment and their relationship in the basin. Results show that a total of 51 species of aquatic macrophytes were detected, including 28 species of emergent plants, 12 species of submerged plants and 10 species of floating-leaved plants, 1 species of floating plant, which accounts for 54.9%, 23.5%, 19.6% and 2.0% of the total, respectively. They formed 14 types of communities, of which 5 were dominated with submerged plants, 6 with emergent plants and 3 with floating leaf plants. The communities varied sharply in environment, especially factors, like NH₄⁺-N, NO₃^--N,TN,TP and PO₄^3- in the water.CCA reveals that water envionment factors,such as TP, PO₄^3-,NH₄⁺-N and DO concentrations, were the key factors determining distribution of the aquatic macrophytes in the Huaihe River Basin.