Ecologia Mediterranea

Existing areas and past changes
of wetland extent in the Mediterranean region:
an overview
État actuel et changements passés de l’étendue des zones humides
en région méditerranéenne : un bilan
Abstract
We quantified the amount of existing wetlands
in the Mediterranean region as well as their
losses in the past century. An estimated 18.5
±3.5 million ha of wetlands existed in c. 2000,
one quarter of them consisting of artificial wetlands,
including primarily reservoirs and ricefields.
Past losses were estimated to represent c.
50% over the 20th century. Land-cover maps
derived from the CORINE Land-Cover system
were also used to test whether they could monitor
total surface areas, surfaces by wetland
types, or wetland losses, at the required scale.
Résumé
Nous avons quantifié la surface de zones
humides existant en Méditerranée, ainsi que
leurs pertes au cours du siècle passé. Environ
18,5 millions d’hectares (± 3,5 millions) existaient
vers l’an 2000, dont environ un quart de
zones humides artificielles, principalement des
réservoirs et des rizières. Les pertes sont estimées
à environ 50 % au cours du XX e siècle. Les
cartes d’occupation du sol tirées de CORINE Land-
Cover ont aussi été utilisées, afin de tester si
elles permettraient de suivre, à l’échelle requise,
la surface totale, la surface par type de zones
humides, et la perte de ces milieux.
ecologia mediterranea – Vol. 38 (2) – 2012
Christian PERENNOU 1, 2 , Coralie BELTRAME 1 , Anis GUELMAMI 1 ,
Pere TOMAS VIVES 1, 3 , Pierre CAESSTEKER 1,4
1. Mediterranean Wetlands Observatory, Tour du Valat Research Centre for the Conservation of
Mediterranean Wetlands, Le Sambuc, 13200 Arles, France
2. Corresponding author: perennou@tourduvalat.org
3. Current address: Biodiversity & Environmental Consultant,
Colon 13, Pollença, E-07460, Mallorca, Illes Baleares, Spain
4. Current address: Office national de l’eau et des milieux aquatiques,
Immeuble « Le Nadar », 5, square Félix Nadar, 94300 Vincennes, France
Keywords: Mediterranean wetlands, Wetland
surface, Wetland loss, Habitat trends, CORINE
Land-Cover, Artificial wetlands.
Introduction
Although wetlands are one of the richest
ecosystems in terms of biodiversity, and one
that contributes most to human well-being,
they are also the ecosystem most threatened
by human activities (Millennium Ecosystem
Assessment 2005). Worldwide, many people
depend on wetlands for their basic needs,
especially for water supply. The international
community has acknowledged their importance:
wetlands are the only ecosystem that
benefits from a specific international convention.
The Ramsar Convention on Wetlands of
International Importance was signed in 1971
in order to ensure their protection and wise
use. But since then and despite conservation
actions implemented by governments and
Non-Governemental Organisations, wetlands
have continued to disappear more rapidly than
other ecosystems (Finlayson et al. 1992).
Wetlands are well represented in the Mediterranean
region, which is itself a biodiversity
hotspot (Mittermeier et al. 2005; CEPF 2010)
due to a combination of high biodiversity and
high level of threats, especially in coastal
areas (Plan Bleu 2009). Regionally, these
threats are particularly acute, both because of
the rarity and irregularity of freshwater
resources, and because of growing human
pressures affecting them directly or indirectly
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