Wetland Action - Rationale

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Importance of wetlands

Wetlands under pressure, communities seeking livelihoods

The Millenium Ecosystem Assessment states that wetlands are one of the ecosystems most under threat. This is mainly due to the expansion of agriculture and especially the poor management of these areas once cultivation takes place in them. In many cases wetlands are over-drained and what was once a very valuable site, with a range of livelihood benefits and environmental functions, becomes degraded and only able to provide rough grazing, at best.

Population growth and economic development have increased demand for food and natural resources, as well as flat sites for urban and industrial use. Wetlands are seen by some as wastelands in their natural state and their valuable services are not recognised. They are often converted completely to other uses which alter the environmental services they can provide.

Commercialisation and expansion of market forces, as a result of improved communications and growing commercial demands, has affected wetlands as demands for various crops have increased. Large-scale commercial use of wetlands occurs especially for sugar cane and rice, while small-scale use of wetlands in Africa typically involves vegetables, sugar cane for local use, and cereals – mostly either rice or maize.

Intensive wetland development has often replaced traditional low intensity multiple uses of these areas. Single use with intensive agriculture over large wetland areas of open access is often difficult to manage and while the immediate benefits may be high, they are often short lived. After several years ecological and hydrological degradation may occur, leading to a complete loss of wetland services and benefits.

Wetland conservation purely for biodiversity reasons can also have negative impacts on local communities where their livelihood uses of wetlands are limited or removed.

Catchment degradation is another issue which, although it occurs outside wetlands, can still impact upon them. Degraded catchments suffer from excessive runoff which may lead to gulley formation in wetlands. Further, there is usually reduced infiltration of water into the catchment and so less water storage here for slow release into the wetland to maintain dry season water supplied.

Analysis of these various pressures on wetlands have led Wetland Action to emphasise the need for a balanced approach to wetland use with multiple use, rather than single use, and for a Functional Landscape approach, which includes sound land use in the catchment to ensure the sustainable functioning of the wetland.

Case study: Dambo degradation in Southern Africa

Dambos, a form of seasonally inundated swamp grassland, occur on the plains of eastern and southern Africa. Because of the availability of soil moisture in dambos during dry periods, these areas are important to local communities who use them for crop cultivation and cattle grazing. In the dry season small-scale agriculture in dambos is practised in the form of maize and vegetable 'garden' cultivation, based on indigenous water management techniques. During the rainy season when most of the dambo remains flooded, rice can also be grown. The decomposition of the grass and sedge dominated vegetation leads to the build up of organic matter in the dambo soil - a valuable agricultural resource.

In recent years, however, dambos have been threatened by an extension of agriculture and overgrazing, caused by a range of socio-economic pressures often linked to government policies. In many areas, this has resulted in a lowering of the water table, and various other effects including soil erosion, a loss in organic matter and a reduction in local water supplies. Those local communities who derive their livelihoods from dambos have suffered as a consequence.

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