While waiting to adequately develop and define the concrete and precise criteria that will serve to draw up the red list of the world's ecosystems in danger, various organisms and scientists, including the Higher Council for Scientific Research, studied twenty of those considered most valuable and threatened. Two years ago it was published in the magazine PLoS ONE a first list that serves as a template for the International Union for Conservation of Nature (IUCN) to draw up a similar list to the one that currently exists for animal and plant species. In this case, the category of extinct is defined as “collapsed”, that is, an ecosystem of great value that cannot be returned to its original state.
To the first list that IUCN works with, we should add the 19 ecosystems present among the 48 places declared World Heritage by UNESCO that it considers to be in danger. Some coincide with the first, such as the coral reefs of the Caribbean (Belize) and the gallery forests of the Senegal River basin (Niokolo-Koba National Park). The Everglades National Park (United States), along with tropical forests, especially those of the Congo Basin in the Democratic Republic of the Congo, in addition to those of Honduras (Río Plátano), Indonesia (Sumatra) and Madagascar (Atsinanana ), also appear on the Unesco red list.
Below is the list of the ten most threatened ecosystems according to the first studies carried out for the IUCN, which are those considered in collapse (Aral Sea) and in critical danger of extinction (the remaining nine). The explanation for the appearance of four places in Australia lies in the fact that they are all concentrated in the area of greatest urban, industrial and agricultural development on the island, the southeast coast, with a population that exceeds thirteen million inhabitants.
1. Aral Sea
The Aral Sea has gone from being the fourth largest lake in the world to not appearing in the top twenty. It only resists 10% of an area that exceeded 67,000 km2, as much as Aragon, Navarra and the Basque Country together. Although efforts are now being made to recover it from its northernmost part, experts believe that it has entered into collapse because it has lost its original biodiversity, including 28 endemic fish species. In addition, the legacy of pesticides, desertification and salinity left by the cotton and cereal crops that were watered with their waters maintains a lethal effect on nature and the population.
2. Acacia forests in the Senegal River basin
Senegal, Mali and Mauritania
Causes similar to those that led to the drying up of the Aral Sea loom over the few fertile floodplains that remain in the Senegal River basin, and especially over the acacia forests (Acacia nilotica) that grow on them. Dams, intensive agriculture and overgrazing are ending hundreds of years of peaceful coexistence between biodiversity and indigenous communities. They had learned to compare agricultural and livestock exploitation with the annual periods of flooding and drought. Now, even the granivorous birds that collaborated in this balance disappear and the breakdown of it causes the forced displacement of thousands of indigenous people and health problems.
3. Raised peat bogs of the Rhineland
Depressions, flooded areas and mounds are distributed among these wetlands full of biodiversity, which present an accumulation of dead biomass that bulges the terrain. This accumulation houses a large carbon reserve, so its gradual destruction releases large amounts of greenhouse gases, responsible for climate change. Apart from the calls for attention from the scientists who have collaborated on this incipient list of endangered ecosystems, the European Commission, as part of its conservation work within the Natura 2000 Network, has warned of the risk of disappearance that the Hunsrück and Eifel peat bogs, where several associated species of fauna and flora have become rare.
4. Thickets of ‘fynbos’ of El Cabo
Up to 8,500 species of vascular plants (in all the British Isles there are 1,400), 70% endemic, enclose these thickets of fynbos, a name of Dutch origin that defines "thin-leaved plants". Due to its variety and color, it is listed as one of the botanical gardens of Africa, with similarities to our Mediterranean forest. Urban expansion, forest fires and agriculture threaten these scrublands in two ways: by direct habitat destruction and by the invasion of exotic species, both plant and animal. In another list, that of the WWF Ecoregions, it is also considered one of the ecosystems most at risk of disappearance.
5. Coorong Lagoons and Murray River Estuary
With the same degree of threat to that of the IUCN (critically endangered), the WWF lists this extensive (140 linear kilometers) and complex (lagoons, lakes, estuaries, riverside forests ...) within its list of Ecoregions, a wetland located southeast of Australia. The declaration of a part as a national park and its recognition as a wetland of international importance (Ramsar Convention) has saved it from disappearing completely, since only 10% of the original surface remains intact, but in a fragmented way. Many conservation organizations continue to raise the alarm about one of the most notorious impacts: the drainage of the wetland towards agricultural lands.
6. Southern karst springs
Piccaninnie Ponds Karst Wetlands.
Piccaninnie Ponds Karst Wetlands, also located on the southern Australian coast, is also a wetland of international importance included in the Ramsar Convention. However, the 862 hectares protected and representative of karst systems, with rising springs and other rock formations and peat originated by groundwater, seem clearly insufficient for the scientific community. To demonstrate the devastating effect caused by the loss of this phreatic layer and the continuity of its upwelling, the IUCN presents the case of the genus of freshwater crabs. Euastacus: Of the fifty species that survive in these ecosystems, 17 are in critical danger of extinction and another 17 in danger.
7. Coastal wetlands of the Sydney Basin
Urbanization, coal mining, fracking, fires, effects of climate change, roads, excessive water regulation, invasion of exotic species ... The Office of the Environment and Heritage of the state of New South Wales, where the bioregion of the Sidney basin, recognizes the threats that surround one of the most unique ecosystems of this island. The same entity recalls that in the last 200 years 60% of the string of coastal wetlands that dotted and beautified these lands has been lost or degraded. Although they are translated as swamps, these are coastal flood plains on sandstone bottoms that jut out mainly on the Hawkesbury Plateau.
8- Wetlands of the Murray-Darling Basin
The Murray River is at 18% capacity.
The Murray and Darling rivers (a tributary of the first) form a gigantic hydrographic basin (twice Spain) transcendental for the water supply of the most populated area of Australia (Adelaide, Melbourne and Sydney) and for the maintenance of one of the highest levels of biodiversity associated with a great variety of swamps, forests and lakes. The problem is that the conflict between human needs (it includes a large agricultural area) and environmental needs affects both, since excessive regulation and water exploitation has led to the elimination of natural vegetation and the temporary drought of sections of the Murray (se estimates that it is at 18% of its capacity), which increases the degree of salinity, which interferes with human supply.
9- Alaska Laminar Forests
Observing a dense formation of giant algae (laminariales) that can exceed 50 meters is the closest thing to entering an underwater forest. The coastal waters of Alaska have very good representations of this ecosystem, which is among the most productive on the planet due to its host capacity for numerous species (including commercially-exploited fish), absorption of carbon dioxide and braking of strong waves. However, overfishing, meteorological phenomena such as El Niño and pollution (the 1989 Exxon Valdez spill) destroy the food chain (mainly affecting sea otters) and leave free way for sea urchins to devour and deforest the kelp forests.
10- Caribbean coral reefs
More than 116 million people live within the coasts that face the Caribbean Sea, to which 20 million tourists are added annually. A study by the World Resources Institute, together with twenty organizations that work in the region, ruled in 2005 that two thirds of the reefs are directly threatened by human activities, and they estimate economic losses of 350 to 870 million dollars per year due to the decrease in fishing for reef, diving tourism and coastal protection services, acting as a barrier against the effects of marine storms. Tourist pressure, intensive agriculture, overfishing and climate change (coral bleaching) are allied to endanger this hotspot of terrestrial biodiversity.