Safeguarding the Pantanal Wetlands: Threats and Conservation Initiatives
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Safeguarding the Pantanal Wetlands: Threats and Conservation Initiatives MONICAˆ B. HARRIS,∗†† WALFRIDO TOMAS,† GUILHERME MOURAO,†˜ CAROLINA J. DA SILVA,‡ ERIKA GUIMARAES,˜ ∗ FATIMA´ SONODA,§ AND ELIANI FACHIM§ ∗Conserva¸c˜ao Internacional–Brasil, Rua Paran´a 32, Campo Grande 79021–220, Mato Grosso do Sul, Brasil †Embrapa Pantanal, Rua 21 de Setembro 1880, Bairro Nossa Senhora de F´atima, Caixa Postal 109, Corumb´a 79320–900, Mato Grosso do Sul, Brasil ‡Departamento de Botˆanica e Ecologia, Universidade do Estado de Mato Grosso, Avenida Tancredo Neves 1095, Cavalhada, C´aceres 78200–000, Mato Grosso, Brasil §ECOTROPICA,´ Rua 3, No. 391, Boa Esperan¸ca, Cuiab´a 78068–370, Mato Grosso, Brasil Abstract: ThePantanal, one of the largest wetlands on the planet, comprises 140,000 km2 of lowland flood- plain of the upper Rio Paraguai basin that drains the Cerrado of central Brazil. The diverse mosaics of habitats resulting from the varied soil types and inundation regimes are responsible for an extraordinarily rich terres- trial and aquatic biota, exemplified by the bird richest wetland in the world—463 birds have been recorded there—and the largest known populations of several threatened mammals, such as Pampas deer (Ozotoceros bezoarticus), marsh deer ( Blastocerus dichotomus), giant otter ( Pteronura brasiliensis), and jaguar ( Panthera onca). Until recently, deforestation of the adjoining Brazilian central plateau was considered the major threat to this area, but now deforestation is a critical problem within the floodplain itself. More than 40% of the forest and savanna habitats have been altered for cattle ranching through the introduction of exotic grasses. And there are other threats that lead to large-scale disruption of ecological processes, severely affecting biodi- versity. Although the Pantanal wetland is a Biosphere Reserve and is considered a Wetland of International Importance, only 2.5% of the upper Paraguai River basin is formally protected. To date, protected areas have been created opportunistically and as such, although of undoubted value, protect only a fraction of the Pan- tanal’s wildlife and habitats. Among the conservation initiatives in the area, the private sector is increasingly participating in the establishment of private reserves. The prospects are far from optimistic, however, and the major challenge is to find alternative socioeconomic models that allow for conservation and economic uses of the land in association with the development of specific environmental legislation that reflects the unique characteristics of the region. Protegiendo a los Humedales del Pantanal: Amenazas e Iniciativas de Conservaci´on Resumen: El Pantanal, 140,000 km2 de llanura inundable de la cuenca alta del R´ıo Paraguai que drena el Cerrado en el centro de Brasil, es uno de los humedales mas´ extensos del planeta. Los diversos mosaicos de habitats´ que resultan de diversos tipos de suelo y reg´ımenes de inundacion´ son responsables de una biota terrestre y acuatica´ extraordinariamente rica, ejemplificada por el humedal con mayor riqueza de aves en el mundo – se han registrado 463 especies de aves – y las mayores poblaciones conocidas de varios mam´ıferos amenazados, como el venado de las Pampas (Ozotoceros bezoarticus), el venado de pantano (Blastocerus dichotomus), la nutria gigante (Pteronura brasiliensis)yel jaguar (Panthera onca). Hasta hace poco, la de- forestacion´ de la meseta central Brasilena˜ adyacente era considerada como la mayor amenaza a esta area,´ pero ahora la deforestacion´ es un problema cr´ıtico dentro de la misma llanura inundable. Mas´ de 40% de habitats´ de bosque y sabana han sido alterados para produccion´ de ganado mediante la introduccion´ de pastos exoticos.´ Y hay otas amenazas que conducen a la disrupcion´ de los procesas ecologicos´ a gran escala ††email [email protected] Paper received December 30, 2004; revised manuscript accepted February 9, 2005. 714 Conservation Biology, Pages 714–720 Volume 19, No. 3, June 2005 Harris et al. Safeguarding the Pantanal Wetlands 715 que afectan severamente a la biodiversidad. Aunque el humedal del Pantanal es una Reserva de la Biosfera´ y es considerado un Humedal de Importancia Internacional, solo 2.5% de la cuenca alta del R´ıo Paraguai esta´ protegido formalmente. A la fecha, las areas´ protegidas han sido creadas oportun´ısticamente y por lo tanto, aunque de valor indudable, solo protegen a una fraccion´ de la vida silvestre y habitats´ del Pantanal. Entre las iniciativas de conservacion´ del area,´ el sector privado esta´ incrementando su participacion´ en el establec- imiento de reservas privadas. Sin embargo, las perspectivas estan´ lejos de ser optimistas y el mayor reto es encontrar modelos socioeconomicos´ alternativos que permitan la conservacion´ y utilizacion´ economica´ de tierras en asociacion´ con el desarrollo de legislacion´ ambiental espec´ıfica que refleje las caracter´ısticas unicas´ de la region.´ Brazilian Pantanal Wetlands tration and abundance of wildlife (Heckman 1999; Swartz 2000). About 124 species of mammals occur there, and The Pantanal is one of the largest continuous wetlands on the Pantanal has the largest known populations of several the planet, covering approximately 140,000 km2 of low- threatened species, such as the Pampas deer (Ozotoceros elevation floodplain of the upper Rio Paraguai and its trib- bezoarticus), marsh deer (Blastocerus dichotomus), gi- utaries, which drain the Cerrado of the central plateau of ant otter (Pteronura brasiliensis), and jaguar (Panthera Brazil. The vegetation is heterogeneous and influenced by onca) (Alho & Lacher 1991; Mour˜ao et al. 2000; Tomas et four biomes: Amazon rainforest, Cerrado (predominant), al. 2000; Sanderson et al. 2002). Mittermeier et al. (2003) Chaco, and Atlantic Forest (Ad´amoli 1981). Different habi- report 423 birds in the Pantanal, but a recent review by tats, soil types, and inundation regimes are responsible for Tubelis and Tomas (2003) resulted in a list of 463 species, the great variety of vegetation formations and the patchy making it the richest single wetland site for birds in the landscapes, which harbor a rich terrestrial and aquatic world. From this total, 117 species are included on at biota (Pott & Ad´amoli 1999). Sixteen vegetation classes least one state, national, or international list of threatened based on phytophysiognomy have been identified (Silva species; the best-known is the Hyacinth Macaw (Anodor- et al. 2000), the most important being grassland (31%), hynchus hyacinthinus)(Tubelis & Tomas 2003; Tomas cerrado woodland (cerradao˜ ) (22%), cerrado (bush sa- et al. 2004). The Pantanal is also an important migratory vanna) (14%), marshes (7%), semideciduous forest (4%), route, with more than 130 species arriving there from gallery forest (2.4%), and floating mats (2.4%). Summers the southern continent (Pampas), the Northern Hemi- (November–March) are hot and rainy and winters (April– sphere, and the Atlantic Forest (Antas 1994; Nunes & October) are warm and dry, except for occasional cold Tomas 2004). A large number of species are seasonal (Cin- spells (Soriano 1997). tra & Yamashita 1990) and transient. Generalist species The main ecological factor that determines patterns are favored within the temporally variable and patchy and processes in the Pantanal is the flooding pulse (Junk habitats (Figueira et al. 2005). Forty-one amphibians, 177 & Silva 1999; Oliveira & Calheiros 2000), which follows an reptile species (M´edri & Mour˜ao 2004), and more than annual, monomodal cycle with amplitudes from 2 to 5 m 260 fishes have been recorded in the Pantanal (Britski and a duration of 3 to 6 months. There is a delay of about et al. 1999). 4 months before the peak water level passes through The Pantanal wetland is recognized as a “National Her- the Pantanal from north to south (Heckman 1999). The itage” in the 1988 Constitution of Brazil and as a Wetland dry season is already under way in the northern Pantanal of International Importance in the Ramsar Convention. when water levels reach a peak in the south. Water levels In 2000, it was designated a Biosphere Reserve by the in any one season in the north are extremely variable, ris- U.N. Educational, Scientific, and Cultural Organization, ing and falling in close response to rainfall. Water levels in and part of it is also a World Heritage Site, affording a the south, on the other hand, rise and fall more smoothly unique opportunity for biodiversity conservation in con- during the year because natural flood retention dampens junction with sustainable development. Referring to its the fluctuations caused by heavy rainstorms (Heckman biological distinctiveness, conservation, and priority sta- 1999). The Pantanal is also subject to a multiyear variation tus, Olson et al. (1998) concluded that the Pantanal is a of flooding intensity, with an alternation of high-flood region that is “globally outstanding, vulnerable and with years and significantly drier ones (Mour˜ao et al. 2000; highest priority for conservation at regional scale.” De- Cunha et al. 2002). spite this, the available data on its biological diversity are Although species diversity is not particularly high still poor and fragmentary (Silva et al. 2001; Silva 2002). (greater in the south than in the north) and endemism The fragile equilibrium of the Pantanal ecosystems, de- is practically absent (probably related to the geomorpho- fined by the dynamics of the periodic flooding, is threat- logical youth of the floodplain—a desert