Mitigating land degradation in Mediterranean agro-silvo-pastoral systems: a GIS-based approach

Agro-silvo-pastoral systems were studied in central–eastern Sardinia Italy. to assess their
environmental impact in marginal Mediterranean areas. Land cover changes between 1955 and
1996 were assessed by using multitemporal aerial coverages. The shift from extensive to
semi-extensive production systems resulted in a decrease in woodland and in a marked increase in
artificial pastures. Related field surveys highlighted widespread land degradation processes in
areas where pasture amendment actions on land characterised by steep or fairly dissected
morphology had been carried out. Starting from a past land suitability classification developed at
farm level, a scheme for the evaluation of the land suitability to the creation of new pastures at
regional scale was developed by using GIS methodologies. The scheme classifies the land into
five land suitability classes as defined in the FAO Framework for Land Evaluation highly
suitable, moderately suitable, marginally suitable, currently not suitable, permanently unsuitable..
The land suitability classification performed by the GIS model showed high accuracy if compared
to the traditional procedure. The comparison between the land suitability and current land uses
allows the identification of areas sensitive to land degradation where land resource conservation
programmes can be proposed.