A botanical classification of standing waters in Serbia and its application to conservation

Abstract

The aim of this study was to describe a botanical classification for lakes in Serbia based on vegetation assemblage, basic water quality parameters and geographic region. Between 2008 and 2010 records from more than 1000 relevés were collated into one dataset. All relevés were derived from synoptic syntaxon tables (1956–2010). In order to fill geographical and methodological gaps in the database, additional field research was carried out during 2008, 2009 and 2010 at 18 new locations, producing a final total of 98 sites, 748 relevés and approximately 22,500 floristic records. Cluster analysis using TWINSPAN (Two-Way INdicator SPecies ANalysis) revealed two main lake vegetation types (LVT1 and LVT2). LVT1 is characterized by typically species-rich, eutrophic sites with Ceratophyllum demersum dominant, followed by Hydrocharis morsus-ranae, Lemna minor, Salvinia natans as constants, while LVT2 comprises species-poor, meso-eutrophic sites with Myriophyllum spicatum constant. These two main lake vegetation types are further divided into four sub-types (LVT1a, LVT1b, LVT2a, LVT2b), and seven site groups. Instead of predicting the vegetation lake groups using predefined physico-chemical categories, the reverse approach has been applied. Altitude and BOD/COD values (as proxies of trophic status) verified the TWINSPAN-derived classification based on lake vegetation. Brief reviews are given to describe national conservation strategy. The results from this study illustrate their value in amplifying descriptions of sites already recognized as important nationally and internationally. In addition, Groups 5 and 6 are considered a potential conservation resource, with six site-targets in particular, representing specific oases for many aquatic species whose natural habitats are endangered by human activity or natural succession.