Short-term signals of climate change in Italian summit vegetation: observations at two GLORIA sites

Abstract

Short-term changes occurring in high mountain vegetation were analysed using the data from two Italian sites already part of the GLobal Observation Research Initiative in Alpine environments (GLORIA – central Apennines and southwestern Alps). The study focused on a set of floristic (endemics), structural (life forms) and ecological (thermic vegetation indicator) variables. Vegetation data were collected according to the GLORIA multi-summit standardized method during the last decade. The re-visitation revealed a moderate decrease in regional endemic flora and significant variations in structural and ecological parameters. The increase in caespitose hemicryptophytes in both sites, in suffruticose chamaephytes in the central Apennines and in rosette-forming hemicryptophytes in the southwestern Alps emerged, highlighting the rapid responses of the alpine vegetation to climate warming. The increase in perennial life forms is related with the expansion of graminoids and small woody plants. These life forms seem to be most suitable to face climate warming in Italian summits. The increase in the thermic vegetation indicator exceeds the mean European summits increment, and this is due to the expansion of thermophilic species. Short-term analyses with fine spatial and temporal resolutions are still necessary to improve our understanding concerning species behaviour in high-elevation ecosystems.

Keywords:

• altitudinal ranks
• climate warming
• endemic species
• life forms
• thermic vegetation indicator
• vascular plants

Additional information

Funding

This work was partially supported by the NextData project (Data-LTER-Mountain). The set-up of the permanent plots and the first data collection in central Apennines was funded by the FP-5 project GLORIA-Europe (2001–2003) under Grant number EVK2-2000-00056 of the European Commission as the re-survey by Life+ project EnvEurope under Grant number LIFE08 ENV/IT/000399. The survey of the southwestern Alps permanent plots was co-funded by European Social Fund, Autonomous Region of Aosta Valley and Italian Ministry of Labour and Social Policies.