The Pantanal is the most extensive tropical wetland region in the world. Estimates of its size range from 54,000 square miles to 75,000 square miles. The Pantanal spreads across parts of South America, especially in western-central areas of Brazil, eastern areas of Paraguay, and eastern areas of Bolivia. The majority of the expanse, however, is situated within Brazil. The natural region is surrounded by a number of ecosystems, including: dry forests, tropical savannas, and arid plains. Dry forests are located in the northwest, west, and southwest, while arid plains lie to the north, east, and southeast. Tropical savannas make up the southern border of the Pantanal.
How Is the Pantanal Formed?
The Pantanal region is located within a natural basin, which is a depression in the ground that is surrounded by higher land. This formation and its relatively low elevation allow water to collect in the Pantanal. Much of the water that flows into the basin comes from waterways (including the Paraguay River) in the surrounding Planalto Highlands region, although rainfall in general also collects in the basin and contributes an average of between 39 and 55 inches each year. The Pantanal's physical appearance changes with each season, and during the wettest months as much as 80% of the region is covered by water. During drier seasons, the wetland empties into the Paraguay River. As it begins to dry up, the basin is characterized by pockets of water, or temporary lakes, where small fish and invertebrate species remain throughout the year. These species provide a dietary source for a number of birds throughout the year.
Geography of the Pantanal
Although specifically categorized as a wetland, the boundaries of the Pantanal also include grasslands and tropical forests. These ecosystems are flooded during most of the year, creating the largest wetland ever recorded. The Amolar Mountains are located at the edge of the Pantanal, with little to no gradual change between the two landscapes. Where the Paraguay River runs through the Pantanal, the water level may fluctuate between 6.5 and 16.4 feet, depending on the season, and it is this area that experiences the greatest change in water level. When the Pantanal is flooded, the water moves at a relatively slow rate as it is prevented from moving quickly by the large quantity of plants in the region.
The entire region stands at an elevation of between 260 and 490 feet above sea level. At its higher elevations, the soil beneath primarily consists of sand, while clay and silt make up the soil at lower elevations. These clay and silt materials are deposits left over from rivers and other waterways as they flow into and out of the region. When the floodwaters reach dry land, oxygen from the water is absorbed or dissolved, leaving the water itself in a state of hypoxia. This lack of oxygen has detrimental results for any animal species inhabiting the waters. However, flooding does allow nutrients from the soil to be carried throughout the region, which promotes fertile soil throughout the Pantanal.
Importance of the Pantanal
The Pantanal natural region is home to a vast array of plant and animal species. Given this abundance of wildlife, its ecological health is extremely important to biodiversity conservation efforts. Additionally, the Pantanal represents a unique landscape that is difficult to find in other areas of the world. As a result of the constant movement of water and changes between flooded wetlands and temporary lakes, typically distinct plant species may co-exist here. Its seasonal patterns also provide an excellent site for researchers to study biological and ecological processes.
In recognition of its importance and uniqueness, four regions within the Pantanal were classified as a UNESCO World Heritage Site (known as the Pantanal Conservation Area) in 2000. The four regions that make up this area include: the Penha, the Pantanal Matogrossense National Park, the Doroche, and the Special Reserves of Acurizal. Together, these regions encompass 187,818 hectares within the Brazilian section of the Pantanal, which represents approximately 1.3% of Brazil's Pantanal ecoregion.
Flora and Fauna of the Pantanal
The Pantanal is home to a vast quantity of biodiverse plant and animal species. In fact, approximately 53 amphibian species, 480 reptile species, 159 mammal species, 400 fish species, 1000 bird species, 3,500 plant species, and over 9,000 invertebrate species have been identified and recorded. Many of these examples of flora and fauna are classified as endangered or near endangered, pointing to the ecological importance of conserving the region. Some of these endangered species include: the maned wolf, South American tapir, hyacinth macaw, marsh deer, giant anteater, and jaguar.
Conservation of the Pantanal
Given the delicate balance of wildlife in the Pantanal, conserving the region is considered important by local governments, international nongovernmental organizations, and local communities. Despite the urgency to conserve the natural region, only the area within the UNESCO World Heritage Site is protected by government regulation. The remaining Pantanal areas are under constant threat, particularly from human development efforts. Some of the most serious and pressing threats to this natural region include: illegal mining, deforestation, livestock grazing, agricultural production, and hydroelectric generation. Additionally, unsustainable and unregulated tourism is quite popular, which can have harmful results on the surrounding environment. Livestock grazing and agricultural production lead to deforestation to make room for growing industries, but these projects also contaminate the surrounding land and water with fertilizers, pesticides, and chemicals expelled from the cattle. Additionally, these endeavors require a large quantities of water, which reduces the water available in the Pantanal and its surrounding areas.
Several organizations are dedicated to the conservation of the Pantanal. One example is the World Wildlife Fund (WWF), which has been working toward increasing public awareness and education, protecting larger areas of the Pantanal, and designing local projects aimed at sustainable development. Some of these projects include: regulating land ownership, providing environmental education workshops, and designing organic cattle farms. The majority of the WWF's efforts are concentrated in Brazil and Paraguay.