Factors Determining the Distribution of Reophil and ProtectedHildenbrandia rivularis(Liebmann) J. Agardh 1851, the Rhodophyta Freshwater Species, in Lowland River Ecosystems

Abstract

ABSTRACT: The relationships of Hildenbrandia rivularis (Rhodophyta), the species composition of its surroundings detailed environmental variables (water chemistry and hydrological, morphological and bottom features) in a lowland river (Welna river, Western Poland) was investigated. H. rivularis from 40 stands was tested together with 25 environmental variables and vegetation. Detrended correspondence analysis (DCA) and redundancy analysis (RDA) were used to describe the relations between the species composition and the selected variables. The uniqueness of this protected species is an ability of formation incrustation on rocks but also coexistence with two groups of species: other algae and vascular plants. In study twenty-two plant taxa were recorded in 40 vegetation plots, including 4 macroscopic algae, 2 mosses and 16 vascular plants. The most common H. rivularis co-occurred with Leptodictyum riparium, Fontinalis antipyretica and Nuphar lutea. Most of the studied plots with red algae were characterised...