Comparing the morphology of Potamogeton perfoliatus L. along environmental gradients in Lake Balaton (Hungary)

¹ Balaton Limnological Research Institute of the Hungarian Academy of Sciences, Klebelsberg K. u. 3, H-8237 Tihany, Hungary
² Research Institute for Soil Science and Agricultural Chemistry of the Hungarian Academy of Sciences, Herman O. ut 15, H-1022 Budapest, Hungary

^* Corresponding author: vari@tres.blki.hu

Received: 26 May 2009
Accepted: 20 April 2010

Abstract

Potamogeton perfoliatus readily adopts different morphological forms, and is therefore especially suitable for investigating variations of aquatic plants' morphology according to different environmental conditions. This paper discusses the morphological diversity of P. perfoliatus at different sites in Lake Balaton, where it occurs as one of the dominant species. We measured 11 morphological variables which were analyzed statistically within the environmental gradients present in the Lake (gradients in trophic condition, water depth and in wave exposure). We found morphological differences between the plants growing on the southern shallow shore which is more exposed to waves and those growing on the northern, deeper and sheltered shore as well as differences along the trophic and the water depth gradient. On the northern shore plants were significantly longer, their internodes were longer and their leaves were relatively thinner (greater Standard Leaf Area). Plants were larger in the more nutrient rich western basins of the Lake and also showed morphological changes along the water depth gradient. The different degrees of wave exposure probably interact partly with trophic differences due to lake morphology. However, we proved that modifications in plant morphology, of which some might be adaptive and therefore of importance in a changing environment, do occur in the common, submerged macrophyte P. perfoliatus in Lake Balaton.