Temporal turnover of the flora of lake islands: The island of Lake Pamvotis (Epirus, Greece).

Maria Sarika,Theodoros Chitos,Maria Panitsa,Alexandros Papanikolaou,Artemios Yannitsaros

doi:10.3897/bdj.7.e37023

Abstract

Lake Pamvotis is one of the Balkan "ancient" lakes, a Quaternary refugium of great environmental importance and ecological value, that is under various anthropogenic pressures. It belongs to a Natura 2000 Special Area for Conservation and Special Protection Area. Almost in the middle of the lake, there is an inhabited island - one of the two lake islands in Greece – that also attracts touristic interest. Τhe main objectives of the present study are to provide a floristic inventory of the protected island, combining data of two different sampling periods, within a 25 year interval, in order to estimate temporal beta diversity and species turnover of the island’s plant diversity. The value of the absolute and relative turnover rates of the floristic diversity of the island studied are 4.24 and 1.72, respectively and are amongst the higher rates reported for plants. The absolute difference between extinct (E) and immigrant (l) taxa is to a great extent accounted, concerning life forms, by therophytes (1.86), hemicryptophytes (1.56) and geophytes (1.04) and, for habitats, by taxa preferring agricultural and ruderal forms (2.52).

Highlights

Lakes are considered as islands in many biogeographical and ecological respects and they are “negative islands”, that is, they are more or less isolated freshwater areas surrounded by a hostile land matrix (Whittaker and Fernandez-Palacios 2007)
The lake belongs to the Natura 2000 Special Protection Area and Site of Community Importance GR2130005 and it is under the responsibility of the Lake Pamvotis Management Body
Lake Pamvotis has been characterised as a Quaternary refugium, that is an ecologically stable area, critical for the long-term survival of existing species, and for the emergence of new ones (Tzedakis et al 2002)

Summary

Introduction

Lakes are considered as islands in many biogeographical and ecological respects and they are “negative islands”, that is, they are more or less isolated freshwater areas surrounded by a hostile land matrix (Whittaker and Fernandez-Palacios 2007). The lake is located at the south-eastern foot of the mountain Mitsikeli and covers 22 km of the basin It is a shallow lake with an average depth of 4.5 m (Sarika-Hatzinikolaou 1999; Sarika-Hatzinikolaou et al 2003). The lake belongs to the Natura 2000 Special Protection Area and Site of Community Importance GR2130005 and it is under the responsibility of the Lake Pamvotis Management Body. It has attracted research interests as a sedimentary archive on long term environmental and climate history and as a hotspot for European biodiversity (Touka et al 2018). The lake could be characterised as an island (sensu Whittaker and Fernandez-Palacios 2007) and almost in the middle of the lake’s vast extent, opposite the town of Ioannina, a true island is formed, named “Nisi” (Fig. 1)

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Conclusion