Ecological corridor

The conversion of large-scale natural areas by deforestation and territorial occupation for commercial production and dwellings (producing urban patches) can also be defined as habitat fragmentation: in this process, after a particular disturbance, a large extent of habitat is subdivided into a number of smaller fragments, representing a smaller total area than the initial habitat and isolated from each other by a matrix habitat different from the original1. Through the process of fragmentation, therefore, a continuous landscape can be transformed into a landscape with previously non-existent elements, and the characteristics of these elements and the form in which they mutually interact may promote biotic and abiotic responses that alter the community’s composition and structure, as well as changing the spatial pattern of the landscape, including the number, size and juxtaposition of elements.

The drastic changes in the landscape geometry and attributes also change the habitat’s microclimate, exposing organisms to insolation, winds and dessication2, altering the community’s composition and structure, since some species are extremely dependent on specific abiotic conditions for their germination, growth, consolidation, flowering and pollinization. Fragmentation also influences interactions between plants and animals, consequently affecting the population density of pollinizers and dispersers and plant demographics and recruitment3.

The Central Amazonia Corridor is located entirely in the state of Amazonas and composed of 81 protected areas, 14 of which are federal CUs (6 Full Protection and 8 Sustainable Use), 15 state CUs (3 Full Protection and 12 Sustainable Use) and 52 Indigenous Lands, totalling 2 million hectares.

The components of the fragmented landscape are therefore: the matrix habitat, the most extensive component of the landscape, highly connected, which controls the regional dynamic4 – that is, a soy plantation, a pine plantation or pasture, and so on, or even an urban patch in the case of cities; surviving fragments of the original habitat, now spatially reorganized into smaller patches and a smaller total area, which are relatively isolated from each other; and corridors, which are units differing from the matrix habitat and connecting the fragments5.

The composition of the matrix habitat is one of the variables that alters the landscape’s connectivity, the latter being the landscape’s capacity to facilitate biological flows – that is, the spatial continuity of the original habitat4. In a landscape composed by a matrix habitat with low permeability, therefore, the mobility of organisms and their consequent dispersal and colonization of new fragments is compromised. A clear example of this situation is a surviving fragment of forest embedded in the urban environment and the high probability of fauna being run over. A more permeable matrix habitat would be an environment with less drastic alterations, closer to the original habitat.

The landscape’s connectivity depends on the proportion of the landscape occupied by the fragments, a characteristic directly related to the size of the fragments and the degree of isolation between them: here the intervening barriers may be spatial or ecological. Bigger fragments with more diverse habitats will be more capable of maintaining ecological processes and a higher number of species and viable populations. Connectivity is also closely related to the existence of corridors: as well as connecting fragments, helping ensure the survival of organisms as they move between the patches, they can provide the temporary or permanent habitat conditions required for some populations to flourish.

Since the emergence of the corridor proposal as an important element in the connectivity of the landscape, many studies have shown their positive effects on species movements6, with some claiming that the recolonization of fragments is often not due to the inhospitality of the habitat but the impossibility of the colonizing species reaching the patches, frequently caused by the absence of corridors7.

The concept of the ecological corridor was incorporated into environmental policies through the National Conservation Unit System (SNUC), which attributed recognition of this territorial unit to the Ministry of the Environment (MMA). The SNUC defines Ecological Corridors as portions of natural or seminatural systems, linking CUs, which enables the flow of genes and the movement of biota between them, facilitating species dispersal and the recolonization of degraded areas, as well as the maintenance of populations whose survival requires areas larger than the individual units. The overall aim is to protect large areas through an integrated set of conservation units of different categories, either located close to each other or contiguous, and their respective buffer zones and ecological corridors, integrating different nature preservation activities, the sustainable use of natural resources and the restoration and recuperation of ecosystems.

 

The Ecological Corridor Project

(Source: MMA – Ecological Corridor Project, accessed October 2014)

The Ecological Corridor Project was conceived within the context of the Pilot Program for the Protection of Brazil’s Tropical Forests (PPG7) as an extensive area of major ecological importance, composed of priority ecosystems for the conservation of biodiversity, conservation units, indigenous lands and interstitial areas. The Ecological Corridor Project has been running within the MMA since 1997, passing through a long process of elaboration. In 1993, the project was discussed at length within ICAMA, and in 1995 a team of consultants hired by the World Bank and led by Márcio Ayres and Gustavo Fonseca presented a draft proposal recommending test cases for the implementation of ecological corridors. In the discussion of these proposals, procedures going beyond the financing of the implementation of CUs were sought, including management plans, investment in infrastructure and personnel training. The Project proposed the development of sustainable economic, social and political frameworks capable of conserving biodiversity in the corridors. The Project’s main goals are:

  • To plan the landscape, integrating conservation units, aiming to connect them and thereby promote the implementation of ecological corridors in the Atlantic Rainforest and the conservation of those already existing in Amazonia;
  • To demonstrate the viability of ecological corridors as a tool for conserving biodiversity in Amazonia and the Atlantic Rainforest;
  • To stimulate changes of behaviour among the actors involved, creating business opportunities and incentives for activities that promote environmental conservation and sustainable use, adding the environmental approach to development projects.

As a large territorial unit with a highly diverse range of plant cover and mixture of land uses and occupations, the ecological corridor is closely dependent on the mobilization, involvement and integrated actions of various sectors: governments, private companies and civil society. Consequently the Ecological Corridor Project has developed a comprehensive, decentralized and participative approach, allowing government and civil society to share responsibility for the conservation of biodiversity and jointly plan the use of natural resources and land, involving and raising awareness among institutions and the public, and creating partnerships at diverse levels: federal, state, municipal, the private sector, organized civil society and residents living close to the protected areas.

Seven large corridors were identified, covering around 25% of Brazil’s tropical rainforests, five of which are located in Amazonia (Central Amazonia Corridor, North Amazonia Corridor, West Amazonia Corridor, South Amazonia Corridor, South Amazonia Ecotone Corridor) and two in the Atlantic Rainforest (Central Atlantic Rainforest Corridor and South Atlantic Rainforest Corridor or Serra do Mar Corridor).

A process of discussions and subsequent adjustments was initiated, including a series of seminars and meetings and various technical reports produced by specialists and NGOs. A second version of this proposal was extensively discussed under the aegis of a technical group comprised of representatives from IBAMA in Amazonas, Espírito Santo and Bahia states, the National Indian Foundation (FUNAI) and various NGOs, with the objective of analyzing in detail the proposal developed by the consultants.

Several versions of the PCE were elaborated and lengthy discussions took place that involved, as well as the technical group (TG) cited above, representatives from the World Bank (manager of the Brazilian Rain Forest Trust Fund/RFT), KfW, GTZ and the European Community (EC). All these institutions offered to help fund the project. After the work of the TG, the Project’s coordination was transferred to the MMA and is today linked to the Department of Protected Areas of the Biodiversity and Forests Office.

Among the seven major corridors identified, priority was given to the implementation of the Central Amazonia Corridor (CCA) and the Central Atlantic Rainforest Corridor (CCMA), with the proposal of testing out different conditions in the two main biomes and, based on the lessons learned, preparing and supporting the creation and implementation of other corridors.

 

Category Unidade de conservação Instância responsável Área (ha) Ano de criação
CEC Caatinga Federal 2006
CEC Central da Amazônia Federal 52.159.206 2002
CEC Mata Atlântica Federal
CEC Parna da Serra da Capivara/Parna da Serra das Confusões Federal 414.565 2005
CEC Reserva Florestal Adolpho Ducke Puraquequara Estadual 2.396 2016
CEC Santa Maria (CEC) Federal 2001

 

Further Information

Site of the Atlantic Rainforest Biodiversity Corridors. Available here.

Ayres, J.M., Fonseca, G.A.B., Rylands, A.B., Queiroz, H.L., Pinto, L.P., Masterson, D. & Cavalcanti, R.B. 2005. Corredores Ecológicos das Florestas Tropicais do Brasil. Belém: Soc. Civil Mamirauá, p. 256.

Instituto Brasileiro de Meio Ambiente e dos Recursos Naturais Renováveis(IBAMA)/ MMA. 2007. Corredores Ecológicos: Experiências em Planejamento e Implementação. Brasília: MMA, p. 57.

Notes and References

  1. WILCOVE, D.S., McLELLAN, C.H. & DOBSON, A.P. 1986. "Habitat fragmentation in the temperate zone". In: Soulé, M.S. (ed.) Conservation biology: the science of scarcity and diversity. 1986. Sunderland, Massachussets: Sinauer Associates.584p. 237-256.
  2. LOVEJOY, T.E., BIERREGAARD, R.O., RYLANDS, A.B., MALCOM, J.R., QUINTELA, C.E., HARPER, L.H., BROWN, K.S., POWELL, A.H., POWEL, G.V.N, SCHUBART, H.O.R & HAYS, M.B. 1986. "Edge and other effects of isolation on Amazon forest fragments". In: Soulé, M.E. (ed.). Conservation biology: the science of scarcity and diversity. 1986. Sunderland, Massachussets: Sinauer Associates.584p. 257-285.
  3. AIZEN, M.A. & FEINSINGER, P. 1994. "Forest fragmentation, pollination, and plant reproduction in a chaco dry forest, Argentina". ECOLOGY 75(2): 330-351.
  4. FORMAN, R.T.T. 1998. Land Mosaics: the ecology of landscapes and regions. Cambridge: Cambridge University Press. 632p.
  5. FORMAN, R. T. T. & GODRON, M. 1986. Landscape ecology. New York: John Wiley Press. 619p.
  6. HADDAD, N. 2000. "Corridor length and patch colonization by a butterfly, Junonia coenia". CONSERVATION BIOLOGY 14(3): 738-754.
  7. TAYLOR, P.D. 1993. "Connectivity is a vital element of lanscape structure". OIKOS 68(3): 571-573.