Ecological Indicators 38 (2014) 282–293 Contents lists available at ScienceDirect Ecological Indicators jo ur nal ho me page: www.elsevier.com/locate/ ecolind The effect of lake morphology on aquatic vegetation development and changes under the influence of eutrophication Agnieszka Kolada ∗ Institute of Environmental Protection – National Research Institute, Kolektorska 4, 01-692 Warsaw, Poland a r t i c l e i n f o Article history: Received 17 May 2013 Received in revised form 9 November 2013 Accepted 15 November 2013 Keywords: Macrophytes Macrophyte metrics Lake morphology Typology Eutrophication indicators a b s t r a c t Data on aquatic and emergent vegetation, morphology and water quality from 274 Polish lowland lakes surveyed in the years 1996–2009 were used to validate the preliminary typology of Polish lakes based on macrophytes and to indicate the environmental parameters which most significantly determine the vegetation patterns in lakes under various morphological conditions. In highly alkaline lowland lakes representing non-disturbed conditions the key determinants influencing the vegetation patterns were mean depth and the shape of the littoral. Three morphological lake types were distinguished: shallow (<3.5 m), deep, and additionally, within the latter, deep ribbon-shaped, with a clearly elongated base and steep bed slopes. The lake types varied in their vegetation patterns developed under non-disturbed conditions. In the shallow lakes, the share of the phytolittoral in the total lake area (%phytol) was the highest (40–100%, 72.3% on average) and the maximum colonisation depth (C max ) the lowest (3.2 m as the maximum) compared to the lakes from both deep types. In the ribbon-shaped deep lakes, %phytol and the plant coverage (%cover) were the lowest, the proportion of submerged vegetation was extraordinarily high (over 90%) and the emergent vegetation was extremely sparsely developed (<6%) compared to the lakes of the two other types. The alterations of aquatic vegetation resulting from the eutrophication process in distinguished mor- phological lake types were explored. Within the macrophyte variables tested, three groups of indicators were distinguished: (a) metrics performing best in selected lake types, i.e. the type-specific indicators (abundance metrics, %Pota), (b) metrics performing equally well in all the lake types, considered as the universal indicators (e.g. S Chara, %Subm and %Emerg) and (c) metrics performing poorly in all the lake types, with generally limited applicability (most of the metrics on syntaxonomic richness). In the shallow lakes, %cover and %phytol performed notably better than in deep lakes, whereas C max worked best in deep lakes and showed the strongest response in the deep regular-shaped lakes. Moreover, in deep regular- shaped lakes the number of communities of stoneworts and submerged plants (S Chara and S Subm), and in deep ribbon-shaped lakes the proportion of area inhabited by vascular plant communities (%Pota) performed exceptionally better than in the other two lake types. The most universal metrics, performing equally well in all the lake types, were the proportions of submerged (%Subm) and emergent (%Emerg) vegetation in the total phytolittoral area. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction According to the contemporary approach to evaluating the condition of aquatic ecosystems, as endorsed by the EC Water Framework Directive (WFD, Directive 2000/60/EC), the structure and functioning of aquatic biota should be considered in biological assessment methods. One of the biological elements which should be included in a bioassessment, is aquatic vegetation. The effect of water nutrient enrichment on aquatic vegetation has been recog- nised for decades and is documented in many previous studies (e.g. ∗ Tel.: +48 22 832 33 01. E-mail address: akolada@ios.edu.pl Seddon, 1972; Phillips et al., 1978; Newbold and Palmer, 1979; Ozimek and Kowalczewski, 1984; Toivonen and Huttunen, 1995). A decrease in light transmission caused by an increase in water tur- bidity, leads to a change in the community structure and a reduction in vegetation density and depth limits (Chambers and Kalff, 1985; Duarte and Kalff, 1986; Middleboe and Markager, 1997). The morphological, hydrographical and catchment conditions of a waterbody may influence the pace and direction of changes in aquatic vegetation patterns resulting from water nutrient enrich- ment. Although the course and impact of eutrophication in shallow and deep lakes are similar, it has been widely recognised that shal- low lakes are more resilient to change than deep ones (Scheffer et al., 1993). According to Phillips (2005), two main factors are responsible for this phenomenon. Firstly, in shallow lakes the 1470-160X/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ecolind.2013.11.015