MICROCLIMATIC RESPONSES OF PLANT COMMUNITIES TO CLIMATIC CHANGES: A STUDY CASE IN THE MEDITERRANEAN COASTAL VEGETATION NEAR ROME

Abstract

The aim of this study is to investigate the microclimates of the different plant communities in the Castelporziano Estate to identify changes at short and medium time, caused by interacting factors at local scale like anthropic disturbance, climatic change and territory management. Air temperature and humidity, soil temperature and PAR (Photosynthetic Active Radiation) were monthly monitored. Measurements were taken in 21 stations, 6 of which along a transect in the vegetation of the dunes and the other 15 stations in forest associations. The dataset have been processed using different statistical treatments: (1) analysis of variance to evaluate the homeostatic capacity of the different communities; (2) analysis of microclimatic deviations values from mesoclimatic data, represented by Castelporziano Estate meteo-climatic stations, to detect microclimatic differences; (3) Multivariate Cluster Analysis to classify the different microclimates. Three main results were obtained: (1) comparison between microclimatic parameters measured during 2007-2008 and previous ones (2003) showed a general tendency of all forest types to shift towards xerophile conditions: air humidity decreased in a large percentage (20%). The woodland with major risk is the Lauro-Carpinetum that looses the 18% of air humidity in a very short period (5 years); (2) vegetation of the dunes displays homeostatic capacity in relationship with structural complexity increasing from pioneer communities of Cakiletum maritimae to mature stands of Viburno- Quercetum ilicis; (3) Cluster Analysis, performed on microclimatic data, allowed to classify vegetation in three different groups, confirming the same patterns obtained by floristic composition. Microclimate resulted a valid and robust tool to detect the ecological status of species and communities, and to follow their temporal changes.