Land terracing for new vineyard plantations in the north-eastern Spanish Mediterranean region:: Landscape effects of the EU council regulation policy for vineyards' restructuring

The landscape of Mediterranean mountain areas in north-eastern Spain, in particular lands traditionally devoted to vineyard cropping, is rapidly changing. This is due to new terrace construction, being built without any environmental impact considerations utilizing heavy machinery. The European Union regulation policy for vineyards' restructuring, which subsidize up to 50% of the land terracing costs, encourages this activity. A clear example of this situation occurs in the Priorat region (Catalonia, NE Spain), where vineyards were first cultivated in the XII century on hillslopes with terracing systems utilizing small stone walls. However, since the 1980s-1990s, the viticulture boom is based on a new terracing system, relying on mechanization and resulting in high negative environmental and landscape impacts. This paper tackles several aspects that this modern land terracing/vineyard system has initiated in the Priorat: (a) the land use changes and rates of changes during the last two decades, in order to determine the magnitude of the environmental and landscape dynamics problem, (b) the assessment of the terrain morphology changes due to land terracing (volumes of soil displaced, slope morphology and slope degree changes) and (c) an analysis of the cost of the restructuring operations, mainly land terracing, subsidized by the EU policy for vineyards' restructuring. In this respect, the effects of this policy are discussed. The results show that modern land terracing methods produce huge material displacements (about 9460 +/- 900 Mg ha(-1)). These figures approximate the range of catastrophic natural mass movements and confirm land terracing as an antrophic geomorphic processes which is rapidly reshaping the terrain morphology. Land terracing costs, which represent 34% of the total costs for a new terraced vineyard, is the operation which receives the maximum EU subsidy. This has encouraged vine growers in the Priorat region to create new plantations, increasing significantly the transformation rate from 7.5 ha year(-1) between 1986 and 1998 to 36.1 ha year(-1) in the 1998-2003 period. (c) 2005 Elsevier B.V. All rights reserved.