Ecological processes can be seriously disrupted by the environmental impacts of activities that are located outside core areas and corridors. For example, air pollution can result in acid deposition, traffic noise can seriously disturb certain animal species and land drainage can lower water tables over a wide area. It will therefore be necessary in certain circumstances to protect the areas of ecological importance from these impacts through the development of buffer zones.
The need to buffer areas of ecological importance will depend on the vulnerability of each particular ecosystem, habitat or species population to changes in environmental conditions, the degree of environmental pressure caused by an activity and the degree to which a particular landscape transmits that pressure to the habitat or species population. The need for and the appropriate design of buffer zones will therefore be determined by local circumstances. However, as in the case of corridors, a considerable degree of flexibility will often be available in determining the configuration of a particular buffer zone and the scope for compatible land uses, such as certain forms of agriculture or forestry.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.
Agenda 21 recommends undertaking and promoting buffer and transition zone management.