engleski

Management effects in the North Adriatic pastoral landscape (Ćićarija, Croatia)

It is known that grassland management acts as driving force in plant community diversity (Kahmen et al., 2002), thus it is important for conservation aims to assess plant communities floristic and functional shifts due to management modification. The analysis of coenological composition and functional traits assessment have proven to be useful in understanding ecosystem dynamics and properties (Scheiner, 1992), making it possible to model shifts related to management or disturbance modification (Kleyer, 1999). A trend of abandonment of the current pastoral landscape has been observed in Ćićarija mountainous plateau (Croatia), proposed for Special Protection Area of Natura 2000 network (about 1, 000 hectares). A similar trend had been observed in the North Adriatic pastoral landscape as well (Poldini, 1989 ; Kaligarič and Poldini, 1997). The research aims were: to understand which factors drive floristic differentiation (environmental features and/or grassland management conditions) and identify the related indicator species sets ; to appraise the effects of management type on the coenological and functional composition of indicator species groups. To achieve the research aims, 73 phytosociological relevés were carried out ; for each of them field data (altitude, aspect, slope, and landform), productivity measurements and information on grassland management were collected. Redundancy analysis (RDA) identified a productivity-related soil moisture gradient as the environmental driving force of grassland floristic differentiation. Environmental parameters explained a higher percent of variance in floristic data set than management (use/non-use). Indicator species analysis (ISA) detected the indicator species groups related to environmental features and management type. Shifts in coenological composition were linked to the establishment of successional species in ungrazed pastures and to the loss of meadow species in hay meadows. The variations that emerged from the comparison of functional characteristics of the indicator species of grazing and of mowing (avoidance strategy, life form, and storage organs) proved more significant than those observed in comparing used and abandoned grasslands. These results can be explained by the low intensity use (i.e., undergrazing and lack of periodic mowing), that is liable to lead to a progressive homogenization of pastoral landscape. The understanding of plant community coenological and functional composition can contribute to optimizing grassland management plans in the study area. This is important especially because Ćićarija calcareous grasslands are very species- rich ecosystems, deemed priority habitats by the European Union (Habitat 62A0, 92/43/EEC Directive) and judged worthy of conservation.

Management effects; North Adriatic; pastoral landscape; Ćićarija; Croatia

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