Three types of gradients in the saline ecosystem

Abstract

The aim of this study was to combine saline ecosystem structure and function by three aspects of the gradient concept: spatial, temporal and functional. The saline meadow was investigated in the vicinity of soda factory in Janikowo in the Kujawy region, central Poland. Three vegetation zones in the salinity gradient were distinguished on the meadow: the Sa/icornia europaea zone, the Puccinellia distans zone and the Elymus repens zone. The results demonstrated that taking into account spatial, temporal and functional gradients, new (informative and ordering) aspects in the collected empirical data sets can be found. Spatial gradient analysis revealed that existence of the two neighbouring Salicornia europaea and Puccinel/ia distans zones is dependent on lower energy than existence of the neighbouring Puccinel/ia distans and Elymus repens zones. Temporal gradient analysis shows the biggest amplitude between the lowest and the highest Cl- concentration values in the Salicornia europaea zone. Therefore the system could be considered as one of the smallest buffer capacity and a labile one. Gradients of vegetation functional changes after decrease and equalisation of the meadow salinity demonstrated that changes in a number of species and in structure of above-ground biomass were recorded at the first stage. At the next stage, only changes in species above-ground biomass were found. The new information obtained by the gradient analysis, especially the one dealing with buffer capacity of the system and changes in species richness after decrease of salinity, could be informative for landscape management.