AN ECOLOGICAL LOOK AT SALINE WETLANDS

摘要

Due to the occurrence of considerable areas of wetlands in the world, the wise, sustainable use of these lands is one of major importance for ecologists and agriculturists. As the presence of indicator species and plant communities can be a measure ofthe compatibility between plants and edaphic conditions in these regions, the ecological niches of plant species in part of the southern coastal areas of the Caspian Sea have been studied to show the correlation of each species with its own habitat. Theplant communities were separated with Ward's cluster analysis. The correlation of these communities and plant species with environmental factors was investigated with the CCA method, using PC-Ordination-4 software. The results showed that the soil EC, water table, soil pH, SAR and ESP were 14-157 dS/m, 0-240 cm, 6.5-8.5, 13.4-84.8 and 2-55%, respectively. This range of values, in addition to creating ecological niches for species with different ecological roles, was also effective in the formation of plant communities. The analysis of vegetation and soil data with the CCA method showed the relationships between soil factors and vegetation. In spite of the dominance of the species Halocnemum strobilaceum in all the plant communities, the correlation ofthis species with plant species such as Aeluropus littoralis, Salicornia europaea, aeluropus lagopoides, Salsoal aurantia and Puccinella distans in relation to changes in EC, water table, pH, SAR and ESP, is important from the point of view of sustaining the physical environment and ecological function. The simplification of these ecosystems (by drainage, agriculture, etc.) may disturb the natural equilibrium. As these ecosystems are susceptible and changes in their use are costly from the ecological and economic points of view, the wise use of ecosystems in their natural forms (rangelands and habitats) is recommended to prevent the spread of salinity and to protect habitats and biodiversity.