Forest Vegetation of Hardwood Tree Species along the Mirna River in Istria (Croatia)

Abstract

background and purpose: The paper presents the forest vegetation of periodically flooded and wet forests of hardwood tree species along the Mirna River (Istria, Croatia). The main objective was to study the older and less influential stands, and to compare them among themselves and with related syntaxa of the Mediterranean and continental area. Materials and Methods: The research was conducted on the basis of 33 new phytocoenological relevés and 12 from previous studies, according to the principles of the standard Central European Phytocoenological School. Results and Conclusions: Based on 45 phytocoenological relevés two main vegetation types were found. In the lowest and periodically flooded habitats grow forests dominated by Fraxinus angustifolia and numerous hygrophilous species. In somewhat higher and drier localities, but with a high level of ground waters, grow mixed forests of Quercus robur, Fraxinus angustifolia, Ulmus minor and Carpinus betulus, with a greater presence of mesophilous species. The paper analyzes their mutual relationship, phytocoenological affiliation, as well as their position with regard to the related syntaxa of the Mediterranean and continental area. The results suggest isolation and a transitional character of the studied forests, which is a consequence of the biogeographical position in the north Mediterranean, of the ecological conditions, and to a lesser extent of anthropogenic influence.