Ecological responses of selected vascular plants to water chemistry parameters in habitat types 3120, 3130 and 3170* (Habitat Directive 92/43/EEC)

Abstract

The article aims to examine the main water chemistry parameters (i.e. conductivity, pH, dissolved O2) and the ecological responses of 20 guide species in Mediterranean Temporary Ponds (MTPs). A complete data-set of 37 MTPs located in two different regions of Italy, Sardinia and Apulia, was compiled and the data were examined by means of Principal Component Analysis (PCA). The pattern of MTPs into the water chemistry space showed a clear separation between the two geographical regions. A “daisy diagram” obtained by overlapping five typologies of MTPs, obtained by the fuzzy cluster analysis and the PCA, revealed a good agreement between the sequence of groups and the water chemistry gradient. Groups of species sharing similar responses to the same chemical features were finally identified. These groups could be effective to acquire detailed information on the characteristics of MTPs and to improve their classification into different typologies. The guide species respond selectively to the wide variability range of conductivity, pH and dissolved oxygen. Despite the small size and the short hydroperiod water parameters in MTPs presented specific patterns to which the guide species are able to give specific responses.