Salvatore Madrau

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.

The geomorphologic and pedo-morphologic maps of Skhirat (Feriana, Tunisia) at the 1:50,000 scale

Land planning and land restoration in drylands affected by desertification require a good understanding of the active geomorphic processes, their intensities and spatial patterns. Traditional Soil and Land Suitability maps do not incorporate this information and may be partially inadequate in that regard, because they necessarily give a ‘static’ representation of the land. The geomorphology of the study area (Feriana district, Central Western Tunisia) is complex, including relict landforms, such as Quaternary pediments, fossil sand dunes, and the evidence of ancient endorheic systems. On the other hand the area is characterized by active and intense geomorphic processes: water and wind erosion, aeolian deposition, and localized present-day endorheism accompanied by water logging and salt accumulation processes. The soils reflect the imprints of multiple past and present pedogenic and geomorphic processes. In this study a Geomorphologic and a Pedo-morphologic Map were produced to provide the local decision makers with cartographic tools to best plan land use options and land restoration. The Maps were drawn at the 1:50,000 scale based on detailed photo-interpretation and on dedicated field surveys.

An Anthroscape from Morocco: Degraded Rangeland Systems and Introduction of Exotic Plant Material and Technology

Fodder shrub plantations (Atriplex nummularia) were extensively introduced to rehabilitate degraded rangeland and to mitigate desertification in the Rural Municipality of Ouled Dlim (Marrakech Province, Morocco). The original rural landscape, characterised by sparse or absent natural vegetation cover due to a long history of intense grazing activities, has been deeply modified during the last decade by these agroforestry interventions. The purpose of this contribution is to describe the occurred environmental changes under the perspective of the Anthroscape concept, by giving emphasis to the description of the Anthroscape units affected by the plantations and to the geo-pedological processes that influenced the technical success obtained by the interventions. Some critical aspects and possible scenarios of the future evolution of the anthroscapes are also discussed.

Land cover changes in Sardinia (Italy): the role of agricultural policies in land degradation

During recent decades in European Mediterranean Countries the shift from traditional to modem agricultural systems, favoured by national and common agricultural policies, has led in many cases to the overexploitation and degradation of natural resources. This is particularly true for Sardinia, where the growing demand for sheep cheese has caused the cultivation of unsuitable areas for forage production.