Natural and antropic sedimentation rates in the salt marsh of the Doñana National Park: Implications for their handling and conservation

Abstract

The salt marsh of the Doñana National Park are one of the most important wet zones in the world. During the last fifty years it has shown a great degradation, due to the intense sedimentation rates. This degradation has influenced in the transformation of its ecological characteristics. In the present work this sedimentation is analyzed, comparing the stages of its Holocene evolution (last 6000 years) with present periods: last five decades (1952-2002) and last four years (2000-2004). The study compares the natural and antropics sedimentation rates; a considerable increase at recent times has been observed. The causes are attributed to the alteration of their hydrologic dynamics, mainly as a result of the channelling and rectifications of the Guadiamar and Guadalquivir rivers. The plans of regeneration elaborated by the Central Administration, trying to palliate this problem, are analyzed.