The composition and structure of macrophyte assemblages in different water bodies from Bulgarian Danube River catchment area for a period of three years were studied. Main environmental variables: water depth and transparency, substrate type, nutrients (ammonium, nitrate, nitrite and total nitrogen, phosphate and total phosphorus) were simultaneously measured. Our aim was to investigate the spatial and temporal variability of macrophyte composition on the taxonomical (species) and functional (life forms) level in relation to environmental factors by means of multivariate analyses (PCA, CCA and RDA). The Bray-Curtis index was also used to investigate species similarities within and between different kinds of water bodies. Hydromorphology and connectivity were the main factors explaining the spatial variations of both species and life forms. The phosphate phosphorus, total nitrogen and temperature were the variables explaining temporal variation of species.

研究了保加利亚多瑙河集水区不同水体中大型水生植物组合的组成和结构，为期三年。主要环境变量：同时测量水的深度和透明度，底物类型，养分（铵，硝酸盐，亚硝酸盐和总氮，磷酸盐和总磷）。我们的目的是通过多变量分析（PCA，CCA和RDA）研究与环境因素有关的分类（物种）和功能（生命形式）水平上大型植物组成的时空变化。Bray-Curtis指数还用于调查不同种类水体内部和之间的物种相似性。形态和连通性是解释物种和生命形式的空间变异的主要因素。