Antonella Veltri

Bioclimatic analysis in a region of southern Italy (Calabria)

In this study, an analysis of precipitation and temperature data has been performed over 67 series observed in a region of southern Italy (Calabria). At first, to detect possible trends in the time series, an analysis was performed with the Mann–Kendall non-parametric test applied at monthly and seasonal scale. An additional investigation, useful for checking the climate change effects on vegetation, has also been included analysing bioclimatic indicators. In particular, Emberger, Rivas-Martinez and De Martonne indices were calculated by using monthly temperature and precipitation data in the period 1916–2010. The spatial pattern of the indices has been evaluated and, in order to link the vegetation and the indices, different indices maps have been intersected with the land cover data, given by the Corine Land Cover map. Moreover, the temporal evolution of the indices and of the vegetation has been analysed. Results suggest that climate change may be responsible for the forest cover change, but, given also the good relationship between the various types of bioclimate and forest formations, human activities must be considered.

Phytoclimatic map of Calabria (Southern Italy)

This study updates Pavaris phytoclimatic map in a region of southern Italy, Calabria (between 37° 50′ and 40° 10′ N and 15° 30′ and 17° 20′ E). A set of homogeneous monthly precipitation and temperature series registered in Calabria and relative to the period 1916–2010 were used. First, temperature data from 28 thermometric stations, over a 30-year period, were homogenized and processed. A multiple regression analysis was carried out between temperature data (annual average temperature, average of minimum temperature and average temperature of the coldest month of the year) as dependent variables and some geographical variables (altitude of the station, continentality and solar radiation) as independent variables. Then, temperature maps of the region were calculated and, finally, temperature and rainfall maps were intersected to define Pavaris phytoclimatic map. The results obtained in this study allow the identification and the delineation of three phytoclimatic belts.

EFFETTI DELLA CEDUAZIONE SULLE PERDITE DI SUOLO IN POPOLAMENTI DI CASTAGNO DELLA CATENA COSTIERA COSENTINA (CALABRIA)

Le utilizzazioni dei cedui di castagno interessano spesso superfici considerevoli, causando alterazioni nei processi idrici ed effetti sull’erosione e sull’idrologia dei versanti. Inoltre, l’alternanza delle tagliate di diversa dimensione ed eta dei soprassuoli determina un mosaico di aree che contribuiscono in maniera diversa ai processi idrologici ed erosivi dei bacini idrografici. Nell’ambito di queste problematiche, in un bacino boscato del versante orientale della Catena Costiera Cosentina, in Calabria, sono state quantificate le perdite di erosione mediante l’applicazione della USLE in ambiente GIS. Inoltre, sono state analizzate le caratteristiche di distribuzione spaziale e temporale dei processi erosivi, al fine di valutare la compatibilita fra le attuali modalita di utilizzazione dei cedui e la conservazione del suolo. I risultati hanno mostrato che il tipo ed il grado di copertura forestale hanno un ruolo centrale nella determinazione del rischio di erosione. Tuttavia, a scala di bacino le periodiche variazioni di copertura, legate all’attuale regime di utilizzazione, non sembrano alterare significativamente l’efficacia antierosiva delle formazioni indagate. Oltretutto, l’effetto della brusca scopertura del suolo e temporaneo e di breve durata, poiche nell’arco di tre stagioni vegetative la copertura vegetale appare in grado di recuperare le condizioni pregresse in termini di efficienza nei confronti dei processi erosivi.

Evaluating the effectiveness of forest crop to mitigate erosion using a sediment delivery distributed model.

In this paper sediment yield data, measured from 1978 to 1997 in a small experimental Calabrian basin reafforested with Eucalyptus trees (Eucalyptus toccidentalis Engl), and RUSLE (Revised Universal Soil Loss Equation) coupled with a sediment delivery distributed model are used to evaluate the antierosive effects of this forest cover. At first, the soil loss measurements carried out in two experimental plots, located in the basin, are used to evaluate the crop and management factor C of RUSLE for Eucalyptus coppice. The reliability of the selected C factor value is verified by comparing, at an event scale, the measured and the calculated sediment yield values at the basin outlet. Then, a Monte Carlo technique is used for evaluating the effects of the knowledge uncertainty and the stochastic variability of the model parameters on calculated sediment yield. Finally, at basin scale, the spatial variability of the crop cover is considered in order to estimate the sediment yield corresponding to scenarios having different percentages of the crop cover.