RESEARCH ON SEVERAL RARE PHYTOCOENOSES IN THE BANAT VEGETATION PUBLISHEDAlina Neacşu, Gicu-Gabriel Arsene, Alina Arsene, Ciprian Stroia
Our research pursues the study of some rare acquatic and paludicolous phytocoenoses from the Banat vegetation, with a view to completing the data existing in the specialized bibliography for the region indicated and the preservation of certain species. The acquatic and paludicolous vegetation, though deemed by many as known well enough, sometimes shelters rare phytocoenoses and species, whose study is important, from the perspective of preserving biodiversity. After referring to the specialized literature, we have noted that the edified phytocoenoses of Najas minor All., Leersia oryzoides (L.) Swartz. and Ceratophyllum demersum L., encountered by us around the acumulation lake Surduc and Liebling, have not been signalled by us in Banat until now. Additionally, according to the European habitat classification systems, their conservative value is high, a decisive factor for their study. Also, we have made some comments on edified phytocoenoses of Eleocharis acicularis (L.) Roemer et Schultes, which, although were signalled and described by SORAN, 1956 (at Liebling), BOŞCAIU, 1966 (at Lugoj) and GRIGORE, 1971 (around the Timis-Bega channel), today they are interesting due to the changes occurred in the floristic composition. On this occasion we have signalled the presence of the species Lindernia procumbens (Krocker) Philcox which, according to O.U. no. 57 of June 20th, 2007, on the regime of the protected natural areas, the preservation of natural habitats, of the wild flora and fauna, is encountered on the list of the species of communitz interest under strict protection. Our research has been performed in the period 2005-2009 and was based on the principles of the Central-European Phytocoenological School, implying the study on the field of the vegetal communities (consisting in performing phytocoenologic sampling and noting all particularities) and in the laboratory (where we performed the data processing and their analysis and interpretation). We consider it expedient to know these phytocoenoses due to their rarity in the Banat vegetation, their significance in the succesion process and the fact that they shelter conservatively valuable species. The factors which may lead to regression or even disappearance of these communities are the water-level fluctuations and the eutrophication (especially from the accumulation lake Surduc, around which, in the last years, increased significantly the number of the buildings). Their value in terms of biodiversity conservation is considered on a regional scale.
phytocoenoses; biodiversity; conservation