Agricultural activities affecting the functions and values of Ramsar wetland sites of Greece

Abstract

Agricultural activities in the agroecosystems neighbouring wetland ecosystems are considered a major threat to the latter in all Mediterranean countries. This threat was investigated in thirteen internationally important wetland sites (Ramsar sites) of Greece. The effects of ten activities commonly practised in the surrounding agroecosystems on four wetland functions and four wetland values were evaluated. The functions were: nutrient removal/transformation, sediment/toxicant retention, flood flow alteration, and ground water discharge. The values were: biodiversity, fishing, hunting, and recreation. It was found that the Adamus' Wetland Evaluation Technique is useful even in the little studied Ramsar sites of Greece. Irrigation is the most decisive activity negatively influencing all functions and values, followed by cropland expansion and overgrazing. Coastal lagoons are the least affected by agricultural activities. It is concluded that in Greece the sustainability of wetland ecosystems depends to a significant degree on the sustainability of agroecosystems. The reverse is also true because wetlands provide irrigation water, crop pollinators, some frost protection, and predators of crop pests. The two ecosystem types are functionally closely linked. Therefore, a national policy for the sustainable development of the soil, water, and genetic resources of Greece must integratively consider both these ecosystems types.