MARSILEA QUADRIFOLIA L. IN THE PROTECTED WETLANDS FROM ROMANIA

Daniela Strat, University of Bucharest, Romania

Abstract

The Romanian Pteridophyta flora has only one species that belongs to Marsiliaceae family of aquatic ferns: Marsilea quadrifolia L. According to the map of European naturally occurrence of M. quadrifolia, this fern species is spread especially between 45° and 50° North latitude, which correspond to the lowlands and flood plains of the main rivers, and hygrophilous grasslands. Its habitats are heavy clay to sandy substrates of permanent lakes and seasonal ponds. The anthropogenic habitats – ditches and rice fields – can be populated by this semi aquatic fern, also. As a hyrophyte, M. quatrifolia grows in mesotrofic to eutrofic waters. The M. quatrifolia become rare taxa throughout its range from Europe because of the lost of natural its habitats (wetland habitats) mainly due to modifications of river courses such as channelisation and embankment, changes of agricultural practice, floodplain drainage and others wetlands, high fertilization. According to assessment of World Conservation Monitoring Centre (1994), M. quadrifolia is threatened in 21 European countries, “Indeterminate” or “Vulnerable” in eastern Palaearctic ecozone, and known to be “Extinct” in Germany, Poland and Switzerland. In European Union this fern is protected by law starting with Bern Convention and followed by Habitat Directive 92/43/EEC – Annex IIb, and Natura 2000 Network. In Romania M. quadrifolia became protected since 1993 after Bern Convention was accepted by Law 13/11.03.1993. According to IUCN Plant Red List for Romania, the species is listed as vulnerable. Population of M. quadrifolia are present in several categories of protected areas in Romania that are important in terms of local, regional, European and international level. However, according to EUNIS database (http://eunis.eea.europa.eu/species/150005/sites), of the 74 Nature 2000 sites with M. quadrifolia in the European Union, 11 sites are in Romania, which are mainly spread in west and south of Romania. One of them is Danube Delta Biosphere Reservation. Despite the apparently suitable habitats, M. quadrifolia is sparsely spread in Danube Delta. The literature mentions four localities: Sulina, Gârla Magearu, Canalul Rusca, and Sfântu Gheorghe village. In the last locality there is a small population whose habitat is a drainage ditch.