Ecophysiological parameters of Lithuanian populations of Phalaris arundinacea

Abstract

Nowadays big attention is paid to the quality of inland waters. Data on quantity of pollutants in the environment are insufficient for understanding of straight consequences of adverse compounds on aquatic flora and fauna. Among water macrophytes of Lithuanian rivers, Phalaris arundinacea plays essential role as the most abundant and frequently occurring species. Nitrogen (N) is the most important nutrient for the plants. Plant productivity depends on processes ongoing in the leaves. In many studies, plant saturation with N is extrapolated from the Ellenberg indicatory values, although data about plant N still remains poor. Our study was aimed to compare leaf N concentrations among riparian populations of Phalaris arundinacea (project was sponsored by Lithuania Research Council; SIT-02/2015). Over 60 populations of Phalaris arundinacea were sampled along basin of the river Nemunas. Only healthy, undamaged leaf blades were used for analyses, done by Kjeldahl method. Examined populations differed in leaf N concentration 1.22 times (p < 0.05). When compared to the other tested riparian species, high enough N concentrations were characterized for Phalaris arundinacea populations. It could be assumed, that present quantities of the N, entering aquatic ecosystems, are big enough to cause eutrophication. For climatic and edaphic conditions of Lithuania, Phalaris arundinacea serves as riparian species accumulating excess N omitted from the agriculture and urban areas