Forest Corridors

Reconnecting forest fragments

The great majority of tropical forests rely on animals (birds, insects, bats etc) to pollinate their flowers. Conversely many fauna species depend on the existence of specific plant species for their nutrition. Many cash crops follow this pattern, too. Tiny midges and thrips pollinate rubber and cocoa; bees and others of the Hymenoptera order pollinate passion fruit and cucurbits, flies pollinate cashew, mango, nocturnal moths and bats pollinate calabash, kapok and balsa trees, and hummingbirds pollinate wild pineapples.

Furthermore, many forest species grow relatively sparsely - that is to say there are not many of that species in a particular area. If the forest size is reduced the number of certain species decreases, and as the forest becomes fragmented, islands can be created without any member of critical species. This makes it impossible for the species to survive.

Studies of survival of forest islands - island biogeography - shows the correlation between the fragment size and the length of time that its biodiversity will survive. The relationship varies from one locality to another, but one study has shown that in a 100 ha forest island, reducing the area by 10% will cause 13% of the species to be lost in 50 years, while 15% loss of area cause a 40% loss of species. In short, the decline in number of species is faster than the rate of the decline in the size of the fragment.

Objectives

To create Forest Corridors to link up forest fragments in the region around Iracambi to the Serra do Brigadeiro State Park.

Activities

• Working with farmers to explain the idea and see how it can best fit in with their needs
• Studying the appropriate size, location and composition of the corridors, including finding ways to make them economically useful by including productive trees, as well as biologically useful in improving habitats for pollinating and seed dispersing fauna;
• Encouraging farmers to plant corridors along their boundaries, which in the Zona da Mata run along ridges, allowing them to reconnect forest island with little sacrifice of land and the burden of the sacrifice is shared by the farmers on both sides of the boundary;
• Supplying seedlings from the nursery.

If you would like to know more about this, click here to see the research paper on Productive Forest Corridors in the Mata Atlântica. (PDF, 2.6Mb)

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