Leonardo Maltchik

Leonardo Maltchik. Ph.D. in Ecology, Universidad Autónoma de Madrid, Spain. Professor, Universidade do Vale do Rio do Sinos (UNISINOS), Brazil. Address: Laboratory of Ecology and Conservation and Aquatic Ecosystems. UNISINOS, 93022-000, São Leopoldo, Rio Grande do Sul, Brazil. e-mail: maltchik@bios.unisinos.br

The inventories of wetlands provide an indication of the location of the land with the highest biological diversity. In Brazil, studies of wetlands stressing the inventory and classification are scarce and three recent inventories have been developed. The establishment of a wetland national inventory in Brazil is necessary and could be started in the semiarid region because of the small amount of surface water and non-complexity of aquatic ecosystems. The wetlands inventory and classification must be encouraged in Brazil. The classification structure should be composed by different levels arranged in an hierarchical fashion. However, Brazil has a long way to go, since basic research related to the wetlands inventory and classification have not been investigated by Brazilian researchers.

Los inventarios de humedales indican la localización de tierras de alta diversidad biológica. Los estudios de inventario y clasificación de humedales son escasos en Brasil, donde recientemente fueron desarrollados tres trabajos. El desarrollo de un inventario nacional de humedales es muy necesario y debería ser iniciado en la región semiárida dada la baja cantidad de agua superficial y la poca complejidad de los ecosistemas acuáticos. El inventario y clasificación de humedales deben ser realizados en Brasil. La clasificación debería ser compuesta por diferentes niveles, organizada en un arreglo jerárquico. Entretanto, Brasil tiene un largo camino a seguir, ya que pocas investigaciones relacionadas a inventarios y clasificaciones de humedales han sido realizadas por investigadores brasileños.

Os inventários de áreas úmidas indicam a localização de terras de alta diversidade biológica. Estudos de inventário e classificação de áreas úmidas são escassos no Brasil e três recentes inventários foram desenvolvidos. O estabelecimento de um inventário nacional de áreas úmidas é extremamente necessário e poderia ser iniciado na região semi-árida brasileira pela pequena quantidade de lâminas de água superficial e não complexidade dos ecossistemas aquáticos. As pesquisas de inventário e classificação de áreas úmidas devem ser fomentadas no Brasil. A classificação deveria ser composta por diferentes níveis arranjada em uma composição hierárquica. Entretanto, Brasil tem um longo caminho a percorrer, já que as pesquisas relacionadas a inventário e classificação de áreas úmidas não tem sido muito investigadas por pesquisadores brasileiros.

Wetlands in their natural state are a source of substantial benefits for society (Vuuren and Roy, 1993). These systems are amongst the most productive ecosystems on Earth and are patches of high biological diversity (Barbier et al., 1997; Hails, 1996; Tiner, 1999). In this context, wetlands are important areas for biodiversity conservation programs. The inventories of wetlands provide an indication of the location of the land with the highest biological diversity and productivity (Taylor et al., 1995), and the information collected through inventories is a necessary prerequisite for policy-making, planning, management and conservation (Pressey and Adam, 1995). The maps created from inventories are useful for planning studies and can help delineating conservation areas (Zalidis and Mantzavelas, 1996).

The classification of wetlands consists of the grouping of similar kinds of aquatic systems in one category (Tiner, 1999). The definition of wetlands more widely accepted internationally was provided by the Convention on Wetlands of International Importance especially as Waterfowl Habitat, in February, 1971. This definition provided a useful starting point for wetland identification and classification, however, it becomes very general when the environmental characteristics of each region are included. Many countries and regions such as the United States (Cowardin et al., 1979), Spain (Bernáldez and Montes, 1989), Australia (Paijmans et al., 1985), Canada (Zoltai et al. 1975), the Middle East (Scott, 1989) and the Neotropical region (Scott and Carbonell, 1986) adopted different definitions of wetlands to include specific characteristics of their regions.

In Brazil, studies of wetlands stressing the inventory and classification are scarce, and only four scientific studies have been accomplished and reported. Unfortunately, most of the terms used to identify inland aquatic ecosystems in Brazil, mainly palustrine formations, are a direct translation from English. Diegues (1990) performed the first inventory of wetlands in Brazil. His interdisciplinary study recognized the importance of wetlands in Brazil and described some types of Brazilian aquatic ecosystems. However, the location and the determination of the extension of different classes of wetlands, and their classification based on ecological studies, has not been done yet. Three recent inventories have been carried out in Brazil; one in the Brazilian semiarid region (Maltchik et al., 1999) and two in the south of the country, in the Rio Grande do Sul State (Maltchik et al., 2003a) and in the municipality of São Leopoldo (RS; Maltchik et al., 2003b).

The Brazilian semiarid region (~1000000km²) has a total of 15781 intermittent shallow lakes and its distribution is quite heterogeneous. While some states have 7358 shallow lakes, others have less than 200 lakes. The total inundation area of shallow lakes is approximately 142000ha and the largest inventoried shallow lake (in the State of Bahia) has an area of 3100ha. A total of 81% of all shallow lakes have an area of less than 10ha and most of them (52.3%) are less than 500m from the heads of intermittent streams. The intermittent shallow lakes and the permanent fluvial pools are the most important biodiversity refuges in the semiarid region. The wetland inventory and classification of the Brazilian semiarid region could be the first step towards the establishment of a national inventory in Brazil for two reasons: 1) the small amounts of surface water in the region and 2) the non-complexity of aquatic ecosystems (low biodiversity and long dry period). The wetland classification in these regions would bring experience to the Brazilian researchers prior to the beginning of a national inventory where the complexity of systems to be included is larger in terms of water origin and of abundance and diversity of aquatic plants.

The State of Rio Grande do Sul (~282062km²) has a total of 3441 wetlands distributed into five wetland classes: lakes and shallow lakes (1506; 4%), rice fields (631; 18%), intermittent lakes and intermittent shallow lakes (569; 17%), floodplains (554; 16%) and marshes (181; 5%). The inundation area of wetlands was approximately 30332km² and the diversity of wetlands classes varies throughout the area of the state. One of the main limitations of this inventory is related to the date of the maps analyzed, since most of them were issued between 1975 and 1980. The accumulated information could not represent the current reality. However, comprehensive inventories of wetlands always have this limitation, mainly in countries of large extension. For example, the U.S. Wetlands Inventory took over 18 years to be finished, and much of the inventoried wetlands became degraded or destroyed during the course of the inventory compilation (Tiner, 1999). On the other hand, these maps, issued by the Ministry of Defense and the Brazilian Institute of Geography and Statistics, are the only ones that are available. Despite the fact that many values may have changed and that the maps updating is extremely necessary, the data they contain are still used by researchers in order to recognize their study sites.

The municipality of São Leopoldo (~103.10km²) has 103 wetlands distributed among 36 palustrine formations, 36 permanent lakes, 26 intermittent lakes, 1 shallow lake, 1 river and 6 streams. The flooding area of wetlands in São Leopoldo is 348.54ha, representing 3.38% of the total area of the municipality of São Leopoldo. The wetlands in the municipality are concentrated in the riparian zone of the Sinos river.

The most important limitation of the inventories made in southern Brazil is related to the terms used to classify the kinds of wetlands. The terms used reflect the lack of hydrogeological studies and of data about dominant aquatic vegetation and hydric soils. The terms are mere translations from the English. However, before a wetland classification in Brazil is elaborated, it is necessary to adopt an internationally accepted definition of the term wetland, as that proposed by the Convention on Wetlands of International Importance. Scott and Carbonell (1986) performed a wetland inventory in South America, employing a broader system classification. Their inventory revealed that approximately 95% of the South American inventoried wetlands belong to six countries, and that Brazil had 50% of the total wetland area (Naranjo, 1995). However, this inventory is not up to date, since the number of wetlands inventoried (368) is small when compared with the inventory developed in the south of Brazil (3441). In this sense, the wetlands inventory in Brazil should be deeply encouraged by Brazilian research foundations and non-governmental agencies, mainly due to the great amount and classes of wetlands and their high biodiversity.

The inventory of wetlands in Brazil will provide several benefits to the development of policies concerning hydric resources and to the national conservation strategies. In the latter aspect, the following aspects must be highlighted: 1) the development of a wetlands information network; 2) the establishment of a wetlands data base; 3) the location of patches with high biodiversity and productivity; 4) the high exchange between surface and groundwater systems; 5) the high possibility of energy and crop production and economic development; 6) the need to expand the number of neotropical countries signataries of the Ramsar Convention; and 7) the need to have the basic framework to develop conservation programs to wetland systems.

Likewise, wetlands classification must be encouraged. The classification would elaborate a national data base of all wetlands in Brazil, including descriptive and geographical information, lists of species of the main fauna and flora taxa, the main functional characteristics, current status, and human use. The classification to be structured should be composed of different levels arranged in an hierarchical fashion. The system and subsystems could follow the classification system adopted by the Ramsar Convention Bureau and the classes should be developed using data of dominant aquatic vegetation. This classification has been done in southern Brazil.

However, Brazil has a long way to go, since basic research related to the wetlands inventory and classification has not been carried out by Brazilian researchers. In this sense, the Brazilian experience in wetlands classification is weak, and an important effort is necessary to revert this situation, extremely important for the management of hydric resources in a country where the water is abundant.

1. Barbier EB, Acreman MC, Knowler D (1997) Economic valuation of wetlands: a guide for policy makers and planners. Ramsar Convention Bureau. Gland, Switzerland. 127 pp.        [ Links ]

2. Bernáldez FG, Montes C (1989) Los humedales del acuifero de Madrid. Canal de Isabel II. Madrid, Spain. 92 pp.        [ Links ]

3. Cowardin LM, Carter V, Golet FC, LaRoe ET (1979) Classification of wetlands and deepwater habitats of The United States. US Fish and Wildlife Services. Washington DC, USA. 140 pp.        [ Links ]

4. Diegues AC (1990) Inventário de zonas úmidas do Brasil: versão preliminar. Prog. Pesq. Cons. de Áreas Úmidas. PRP, USP. Brazil. 426 pp.        [ Links ]

5. Hails AJ (1996) Wetlands, biodiversity and Ramsar Convention: the role of the convention wetlands in the conservation and wise use of biodiversity. Ramsar Convention Bureau. Gland, Switzerland. 196 pp.        [ Links ]

6. Maltchik L, Costa MAJ, Duarte MCD (1999) Inventory of Brazilian semiarid shallow lakes. Anais da Academia Brasileira de Ciencias 71: 801-808.        [ Links ]

7. Maltchik L, Costa ES, Becker CG, Oliveira AE (2003a) Inventory of wetlands of Rio Grande do Sul (Brazil). Pesquisas: Botânica 53: 89-100.        [ Links ]

8. Maltchik L, Bertoluci VDM, Erba DA (2003b) Inventário das áreas úmidas do município de São Leopoldo, Rio Grande do Sul, Brazil. Pesquisas: Botânica 53: 79-88.        [ Links ]

9. Naranjo LG (1995) An evaluation of the first inventory of South American wetlands. Vegetatio 118: 125-129.        [ Links ]

10. Paijmans K, Galloway RW, Faith DP, Fleming PM, Haantjens HA, Heyligers PC, Kalma JD, Loffler E (1985) Aspects of Australian wetlands. CSIRO. Melbourne, Australia. 244 pp.        [ Links ]

11. Pressey RL, Adam P (1995) A review of wetland inventory and classification in Australia. Vegetatio 118: 81-101.        [ Links ]

12. Scott DA (1989) A directory of Asian wetlands. IUNC. Gland, Switzerland and Cambridge, U.K. 560 pp.        [ Links ]

13. Scott D, Carbonell M (1986) Directorio de Los Humedales de la Region Neotropical. IUNC. Gland, Switzerland. 713 pp.        [ Links ]

14. Taylor ARD, Howard GW, Begg GW (1995) Developing wetland inventories in Southern Africa: A review. Vegetatio 118: 57-79.        [ Links ]

15. Tiner RW (1999) Wetland indicators. Lewis. New York, USA. 392pp.        [ Links ]

16. Vuuren WV, Roy P (1993) Private and social returns from wetland preservation versus those from wetland conversion to agriculture. Ecological Economics 8: 289-305.        [ Links ]

17. Zalidis GC, Mantzavelas AL (1996) Inventory of Greek wetlands as natural resources. Wetlands 16: 548-556.        [ Links ]

18. Zoltai SC, Pollett FC, Jeglum JK, Adams GD (1975) Developing a wetland classification in Canada. In Bernier B, Winget CH (Eds.) 4th North American Forest Soils Conference. Laval University Press, Canada. pp. 497-511.        [ Links ]