Macrophytes of the River Ižica - comparison of species composition and abundance in the years 1996 and 2000

Abstract

This paper presents a comparison of species composition and abundance of macrophytes of the River Ižica between the years 1996 and 2000. In both surveys 24 species of macrophytes were identified in the river. At the very source some species, characteristic of moderate nutrient concentrations habitats (Berula erecta, Callitriche cophocarpa and Veronica anagallis-aquatica) were found along with some species characteristic of moderately eutrophic habitats (Cladophora sp., Elodea canadensis). Species characteristic of nutrient-rich habitats (Nuteum lutea, Potamogeton pectinatus, and Sagittaria sagittifolia) occurred mainly in the middle and lower parts of the river. Changes in the abundance and distribution indicate a higher level of eutrophication in 2000. Cladophora sp., Nasturtium afficinale, Nuphar lutea, and Sagittaria sagittifolia were more abundant, whilst Batrachium trichophyllum, Berula erecta, Scirpus lacustris, Sparganium emersum, Callitriche cophocarpa and Elodea canadensis were less common.