A phytosociological survey of aquatic vegetation in the main freshwater lakes of Greece

Dimitrios Zervas,Vasiliki Tsiaoussi,Erwin Bergmeier,Ioannis Tsiripidis

doi:10.3897/vcs/2020/48377

Abstract

Aims: This study aims to contribute to the knowledge of European freshwater lake ecosystems with updated and new information on aquatic plant communities, by conducting national-scale phytosociological research of freshwater lake vegetation in Greece. Moreover, it investigates the relationship between aquatic plant communities and lake environmental parameters, including eutrophication levels and hydro-morphological conditions.Study area: Lakes in Greece, SE Europe.Methods: 5,690 phytosociological relevés of aquatic vegetation were sampled in 18 freshwater lake ecosystems during 2013–2016. The relevés were subjected to hierarchical cluster and indicator species analyses in order to identify associations and communities of aquatic vegetation, as well as to describe their syntaxonomy. Multiple regression analysis was applied to investigate the relationship between vegetation syntaxa and environmental parameters of lakes, i.e. physico-chemical parameters and water level fluctuation.Results: Ninety-nine plant taxa belonging to 30 different families were recorded. Forty-six vegetation types were identified and described by their ecological characteristics, diagnostic taxa and syntaxonomical status. Thirteen vegetation types, the largest number belonging to the vegetation classCharetea, are considered to be new records for Greece. The distribution of the vegetation types recorded in the 18 freshwater lakes was found to depend on environmental parameters and levels of eutrophication.Conclusions: An updated aquatic vegetation inventory was produced for Greek lakes, and primary results showed that the presence/absence of aquatic plant communities and the community composition in freshwater lakes can be utilized to assess the pressure of eutrophication on lake ecosystems.Taxonomic reference: Euro+Med (2006–).Abbreviations: MNT = Mean number of taxa; WFD = Water Framework Directive.

Highlights

Freshwater ecosystems are among the most threatened ecosystems around the world (Sala et al 2000; Foley et al 2005; Dudgeon et al 2006)
Dimitrios Zervas et al.: Aquatic vegetation in Greek lakes work, the monitoring of aquatic plant communities was proposed as a key element in order to assess the ecological status of freshwater ecosystems, as macrophytes play a significant role in determining the structure and functions of lake ecosystems by influencing environmental conditions, nutrient cycling, and biotic assemblages and interactions (Carpenter and Lodge 1986; Jeppesen et al 1997; Engelhardt and Ritchie 2001)
Twenty-six out of 99 taxa were recorded in three or fewer plots

Summary

Introduction

Freshwater ecosystems are among the most threatened ecosystems around the world (Sala et al 2000; Foley et al 2005; Dudgeon et al 2006). Publications containing phytosociological data for lacustrine aquatic plant communities have accumulated over time, but remain scarce and not evenly distributed across the country: Gradstein and Smittenberg (1977: western Crete), Lavrentiades and Pavlidis (1985: Lake Mikri Prespa), Papastergiadou (1990: various lakes in Northern Greece), Bergmeier (2001: seasonal pools in the island of Gavdos), Sarika-Hatzinikolaou et al (2003: seven lakes in Epirus), Grigoriadis et al (2005: Agras wetland), Dimopoulos et al (2005: Kalodiki marsh); Zotos (2006: Lakes Trichonida and Lysimachia), Fotiadis et al (2008: Lake Chimaditida), and Pirini (2011: Lakes Vegoritida and Petres) These studies provide important information about aquatic vegetation in Greece, but the older ones do need to be revised and updated. Of the three transboundary lakes (Doirani, Megali Prespa, Mikri Prespa) only their Greek areas were studied

Methods

Results and discussion

Conclusions