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South America's giant Pantanal wetlands, one of the world's most bio-diverse ecosystems, is at growing risk from intensive peripheral agricultural, industrial and urban development – problems expected to be compounded by climate change, United Nations University experts warn.
Covering more than 165,000 square kilometers – an area roughly equal to Florida – in the heart of South America, the Pantanal is the world's largest freshwater wetland, of active interest to U.S. scientists for insights into the lost biodiversity of Florida's famed Everglades, altered by drainage projects starting in the 1940s to make way for development and agriculture.
In a message to mark World Water Day, March 22, UNU says the Pantanal provides enormous environmental services by storing and purifying water, providing storm protection and flood mitigation, and stabilizing the local climate, particularly rainfall and temperature.
Today, however, these services are compromised by the global problem of climate change while local pollution, habitat destruction and narrowing migration corridors for many species are among the consequences of introducing intensive agriculture, modern cattle ranching, energy production, mining and other changes in land use in and around the Pantanal.
"Without extremely careful integrated management, one of the planet's greatest environmental treasures will be altered forever by human encroachment," says Prof. Hans van Ginkel, UN Under Secretary-General and Rector of UN University.
UN University and Brazil's Universidade Federal de Mato Grosso jointly run the Pantanal Regional Environment Programme (UNU-PREP), under the direction of Dr. Paulo Teixeira de Sousa Jr.
Straddling the territories of Brazil, Bolivia, and Paraguay, the Pantanal is a patchwork of lakes, lagoons, rivers, forest and forest islands. It is dry half the year and a shallow lake the rest, creating a unique habitat for thousands of species, many endangered, including more than 650 bird species, over 190 species of mammal, 50 reptiles, more than 1,100 butterfly species and 270 fish species. It is also the wintering grounds for a large number of migratory birds that summer in North America.
According to an analysis by UNU-PREP and the Japan-based UNU Institute for Advanced Studies: "While large parts of the Pantanal have remained pristine, today the ecosystem is under unprecedented pressure from economic development, alterations of its water courses and conversion to other land uses."
"Moreover, global climate change poses great environmental threats to wetlands," according to the analysis, "fundamentally altering their ecology, biodiversity and species composition."
The global threat to the Pantanal: Climate change
The UNU analysis says a warming of 3° to 4°C could eliminate 85% of all remaining wetlands in the world. It says wetlands hold roughly one-sixth of all carbon held in terrestrial sinks, most of it organic matter in soil which can be released when the soil is disturbed, for example through wetlands drainage and destruction.
Already, changes in land use and land cover account for about 1.6 gigatonnes (17%) of annual human-caused carbon emissions, the analysis says. And by 2100, "the terrestrial biosphere, which is at present a carbon sink, is projected to become a carbon source."
"The release, maintenance or enhancement of these stores under a changing climate will in turn potentially affect future climate change."
As temperatures rise, species will migrate towards higher latitudes and altitudes in both hemispheres, and the species composition and functioning of plants will be altered, particularly the efficiency with which they use water.
If the climate changes rapidly, as projected, mismatches may occur between the new climatic conditions and plants that have adapted to current conditions over centuries.
"Maintenance of wetlands in their current state, and thus the goods and services they provide and the species they support, is crucially linked to averting serious changes in land use and climate change," the analysis says.
Local threats to the Pantanal
"Traditional Pantanal commodities – mainly cattle and fishing – cannot compete in today's marketplace," says UNU-PREP Director Dr. Teixeira. "Traditional farmers are selling their land to outsiders and large scale agriculture is taking place in the high-lands surrounding the Pantanal. In most cases, these newcomers do not know how to manage the land in a sustainable way."
Several major development projects have been initiated, aimed at increasing the contribution of the Pantanal and its catchment area to the economy. "This economic development and consequent population growth, pose a new threat to the Pantanal due to their negative environmental consequences," the analysis says.
Roads and electricity lines have been constructed, while large agri-industrial projects have emerged on the Pantanal's periphery – large-scale cattle ranching and plantations of soybean and sugarcane – all fostering population growth.
"The resultant pollution of water and soil from farm chemicals, as well as increasing industrial pollution from urban centres, has become a problem."
The analysis says "the activities of these new stakeholders have impacted on the watershed on a large scale.
In highlands surrounding the Pantanal, "the implementation of industrialized soybean, corn, sugar cane and cotton monoculture transformed millions of square kilometers of savannah, into open fields. Riparian forests along rivers have been cut down or degraded which has led to increased erosion and sedimentation, and disruption of the local hydrologic pattern. This has made navigation difficult and also hindered waterfowl and fish migration."
Local cattle raising in the Pantanal has declined due to competition from highland cattle breeding where pastures may be used all year round.
The analysis says "new landowners from outside the Pantanal frequently apply non-sustainable practices."
"Prior to the 1970s, the traditional stakeholders had limited impact on the resources they used and did not have the means to induce major environmental changes, such as altering the flood pulse by building dams or changing water quality by increasing the sediment load in rivers."
"As economic development proceeded rapidly however, new stakeholders emerged along with the industrialization such as agriculture, modern cattle ranching, transport industry, hydroelectric energy production and mining. The Pantanal's distinctive ecosystem is also increasingly under threat from tourism and over-fishing."
Dr. Teixeira says the loss of traditional cattle farming is facilitating fire in the dry season. Without cattle to eat or step on the grass, it gets dry and more easily burns, leading to more frequent fires which destroy flood-adapted trees, in which aquatic birds nest, while killing swamp deer and other animals. (The Pantanal's other fauna includes giant anteaters, armadillos, capybara, the Brazilian tapir and jaguar, and endangered species like the howler and capuchin monkeys, caiman, and giant black eagle.)
Moreover, several large transportation infrastructure projects, including a railway and three waterway or Hidrovia projects (one of them in the Pantanal itself), have been initiated to service metropolitan areas and seaports.
A large-scale project involving Brazil, Paraguay, Bolivia, Uruguay and Argentina "is of particular concern for the sustainable management of the Pantanal," the analysis says. The goal: to improve river barge traffic through dredging, channel modification, and port installation.
"Depending on how it is implemented, this project could potentially modify various key ecological processes in the Pantanal, including the flood pulse. The Hidrovia, if fully constructed, would reduce the area flooded in the Pantanal."
Meanwhile, a large hydro-electrical facility was recently constructed on the Manso River, a principal tributary of the Cuiabá River, a project designed also to regulate seasonal flooding. A lower and shorter flood peak in the Cuiabá River, however, could have profound ecological impacts in the northern Pantanal.
"Inter-linkages approach" needed to manage the Pantanal
The complex interconnections and inter-linkages at the ecological level – as for example, between climate change and biodiversity – underline the need to develop inter-linkages at the policy level as well, UNU says. In other words, the environmental, economic, and social impacts of activities of stakeholders in the Pantanal should be considered in managing the wetlands.
It says improved coordination at the regional level will lead to more effective management of the Pantanal and similar wetlands.
"In order to identify and effectively use the synergies that exist in the natural environment, a systematic approach to environmental decision making and management is urgently needed. The Interlinkages approach offers a coordinated way to achieve this goal," the analysis says.
"Because of the transboundary nature of many ecosystems and environmental problems, they are often addressed at the regional level; the Pantanal is a case in point. Regional institutions can take global environmental issues and refocus them into priorities and a manageable agenda for national governments…"
"So far, however, most work on Inter-linkages has been undertaken at the global rather than regional or national levels. Recognizing the importance of cooperation at the regional level between Brazil, Bolivia and Paraguay--the three countries in whose territory the wetland lies-- stakeholders at the workshop convened by UNU-PREP and UNU IAS in Brazil in October 2003 expressed their willingness to draft a treaty for the sustainable management of the Pantanal wetland.
"The challenge now is to translate this will into action."
Established by the U.N. General Assembly in 1973, UNU is an international community of scholars engaged in research, advanced training and the dissemination of knowledge related to pressing global problems. Activities focus mainly on peace and conflict resolution, sustainable development and the use of science and technology to advance human welfare. The University operates a worldwide network of research and post-graduate training centres, with headquarters in Tokyo.