ABSTRACT
Environmental services of the forest: an essay in an European Atlantic river basin based on a Central American experience. A Conservation Interest Index (CI) was designed to numerically assess the natural quality or value of a given terrestrial area. This CI has been applied along the Golako River Watershed (Biosphere Reserve, Basque Country, Spain). The area, although benefiting from some protection, is strongly influenced by human activities (forestry and cattle breeding). The CI is based on both available cartographic information about vegetation and fieldwork, the later needed to provide estimations for the various descriptors included in this index: in this way, a particular vegetation fragment received a final score on a scale from 0 to 1 000. A set of 9 Vegetation Units has been defined to analyze the current vegetation profile and, a ten plot (500 x 500 m) uniformly distributed sampling design has been implemented. Landscape homogenization is high where main land use relies on timbering, contrasting with the more heterogeneous and fragmented profile related to rural activities. At a height of more than 150 m forest appears to be dominant while human occupation becomes patchy, whereas abruptness restraints farms to locations below 100 m. Concerning the index performance, gradual differences have been displayed by the forest, which appears as the only vegetation unit attaining values above 500 (50% in the index scale), mature forest ranking highest (860), followed closely by the riparian forest. We have developed a formula to translate environmental value into economic benefit to promote conservation work at private property level, imitating the initial work undergone in Central American countries, where environmental services are rewarded irrespective of their conservation status. Rev. Biol. Trop. 56 (4): 2087-2098. Epub 2008 December 12.
Se presenta la síntesis de un estudio piloto llevado a cabo en la Reserva de la biosfera de Urdaibai (España atlántica), en la cuenca del río Golako, donde se estudió 250 hectáreas durante 8 meses. El objetivo fue definir un índice cuantitativo de conservación del territorio (IC), basado en la evaluación individual de 9 unidades de paisaje (UP) que sintetizan las características de la zona. Luego, se formuló un método de compensación económica (PSA = euros), que permite la conservación de las áreas naturales de calidad que son propiedad privada. Dicho planteamiento se basa en la premisa de que el bosque natural, como todos los ecosistemas naturales, posee un valor social que puede ser cuantificado. Los resultados del estudio indican que el 60% del territorio está representado por plantaciones de Pinus radiata, y que la superficie ocupada por el bosque natural en estados variables de conservación, está extraordinariamente fragmentada (82% por debajo de 1 ha). En este contexto, se desarrolla un concepto de Pago por Servicios Ambientales (PSA) propio, diseñado tomando en cuenta: las características específicas del territorio; los estudios de Costa Rica; los planes estratégicos y jurídicos vascos; el estudio del impacto de la actividad forestal; y las funciones del bosque natural como estabilizador de sistema.