Ecophysiological behaviour of halophytes communities in relation with natural habitat characteristics from Razelm lake vicinity (Danube Delta biosphere reserve)

Abstract

The investigations were carried at the low, flat and flooded area near Razelm, Enisala, Beibugeac (Plopu) and Saraturii lakes (Murighiol) in Danube Delta Biosphere Reserve in different areas: 1310 - communities of Salicornia and other annuals colonising mud and sand; 1530* Pannonic salt steppes and salt marshes. The ecophysiological analyses were performed in representative plants belonging to the three identified plant associations (communities): Salicornietum prostratae Soó 1964, Astero tripoli – Juncetum gerardii Šmarda 1953 and Obionetum verruciferae Ţopa 1939. Investigated soils, Gleyc Solonceak and Sali-sodic Gleysoils, have medium or coarse-medium texture and electrical conductivity values varied from 1019 µS/cm up to 5427 µS/cm. The chlorophylls biosynthesis showed a higher amount of chlorophyll a in species of Poaceae and Juncaceae than in the Chenopodiaceae family. In Aeluropus littoralis species of the C4 - photosynthetic type, photo-assimilatory pigments varied slightly during the vegetation period. Among the carbohydrate fractions, the disaccharides, important in maintaining cell osmotic pressure, are increased and as well as polysaccharides.