Creating wildlife corridors

Creating contiguous natural areas can increase the genetic diversity of native biota and encourage the survival of rare, threatened, and endangered species that are isolated as metapopulations.

Where the fragmentation of a habitat of importance is having a negative impact on biodiversity, the restoration of connectivity between different patches of the habitat may help to limit the problems. In general, the smaller and more isolated the patches of habitat, the greater will be the need for corridors to enable local species populations to disperse and migrate between different core areas. The ecological value of a corridor will also depend on its design and on the characteristics of each individual species (such as its need for mobility and its ability to move through a particular landscape).

Some people consider corridors to be hedgerows and other linear features in the landscape. Others interpret corridors more broadly by also considering stepping stones and mosaic landscapes as corridors. Often the scales on which corridors are considered determine the interpretation.

Conservation buffers are strips of land that are maintained in permanent vegetation and designed to enhance wildlife habitat, improve water quality, and enrich the aesthetics on farmlands.

Conservation of a large number of plant and animal species depends on whether they have sufficient opportunities to move around and to migrate, in transfrontier areas, which are proper ecological corridors, as well as in "interterritorial areas", which serve as "stepping stones."

Although each species has its own specific requirements for habitat size and mobility, there will usually be considerable scope for adapting the physical form of a corridor so as to take into account the characteristics of local human activities. Corridors need not always be continuous linear pathways. Certain kinds of less intensively used landscape or so-called "stepping stones" of smaller landscape elements such as ponds may also provide the appropriate degree of interconnectivity. It is also important to recognise that various kinds of land use may be compatible with the function of a corridor and considerable flexibility may be possible in deciding a corridor's route and dimensions.

Broad guidelines on the potential role of corridors and their configuration include: (a) the greater the width, richness and continuity of a corridor, the greater the number of species that it will serve and the easier that movement along the corridor will be; (b) although the requirements for corridors are species-specific, single corridors can serve a group of species with similar requirements; (c) well-connected habitat fragments assist some animals in finding sufficient habitat where a single habitat fragment is insufficient; (d) corridors are essential for animals that have to migrate between different isolated areas in order to meet their seasonal requirements; and (e) corridors can help only those species that have a significant barrier to cross and which are able to use the habitat of the corridor.

On 29 October 1998 in Paris, representatives from the Central American countries and international donors and NGOs agreed to launch the Mesoamerican Biological Corridor (MBC). While other multi-country efforts have aimed at preserving waterways, riverbeds and seas, this is one of the first seeking to preserve large tracts of land spanning numerous international borders. Implementation of the Mesoamerican Biological Corridor will: (a) Preserve endangered animal species: While the area encompasses less than one percent of the total land surface of the world, it contains approximately 7% of the planet's biodiversity, including a myriad of unique animal species. Without the MBC, multiple barriers prevent the movement of these species along the biological highway between North and South America. Isolation of animals could lead to the extinction of species native to the region; (b) Increase the capacity for carbon sequestration: By providing an agenda for investment in humid tropic and pine managemnt and enhancing the regional capacity for fire control and prevention, the MBC will mitigate the negative effects of global warming by contributing to the reduction of CO2 emissions; (c) Reduce vulnerability to climate change: By promoting initiatives that mitigate flood and prioritizing fragile zones such as strategic watershed areas, sources of drinking water, slopes of gradients and vulnerable erosion, the risks of climate change can be reduced; (d) Protect ancestral homes: The land included in the MBC is predominantly occupied by the region's indigenous populations. Without a concerted effort to preserve this area, hundreds of thousands of their ancestral lands will likely by lost; and (e) Alleviate poverty: The MBC Program not only aims to preserve biodiversity, but also address the socio-economic development needs of Central America. It recognizes that conservation can not be addressed in isolation from urgent development imperatives.

Under the provisions of the EU Habitats Directive, European Member States shall endeavour in their land-use planning and development policies to encourage the management of features of the landscape which are of major importance for wild fauna and flora. Such features are those which, by virtue of their linear and continuous structure (such as rivers with their banks or the traditional systems for marking field boundaries) or their function as stepping stones (such as ponds or small woods), are essential for the migration, dispersal and genetic exchange of wild species.