The vegetation of semi-natural grasslands and refugial scrubs in the northern Apennines (N-Italy)

Aims: This paper presents the results of a phytosociological research on abandoned semi-natural grasslands and refugial scrub vegetation in the northern Apennines. The objectives were: 1) to identify the vegetation units, classify and describe them, and 2) to detect the ecological gradients underlying different vegetation units. Based on the current floristic composition of the target communities, we formulated hypotheses to trace the origin of the target communities and then suggested possible trajectories of change under the combined effects of land abandonment and global warming. Study area: The study area lies in the northern Apennines and, specifically, the vegetation was sampled in the Tuscan-Emilian Apennines and the Apuan Alps. Methods: The study was based on a dataset including 255 relev & eacute;s taken according to the Braun-Blanquet method and classified following an unsupervised numerical procedure. Species fidelity was used to define the diagnostic species of the associations. PCA and RDA ordinations were employed to perform ecological analyses using both Ellenberg Indicator Values as indirect variables and directly measured or calculated variables. Results: The cluster analysis defined seven vegetation types, classified as plant associations and described according to their floristic composition, structure, syntaxonomy, habitat and distribution. Associations were assigned to five different classes. The syntaxonomic scheme followed that proposed in the EuroVegChecklist, with few minor exceptions. Conclusions: All associations were endemic to the study area and five of them were described here for the first time. The most important factors driving the differences between associations were temperature, soil moisture and reaction, and potential solar radiation. It could be hypothesised that some grasslands derived from shrub vegetation and others from different types of mesophytic primary grasslands. Prolonged drought events associated with high temperatures during the summer are expected to exert a negative impact on the tussocky grasses dominant in the abandoned semi-natural grasslands in the long term.