''How can I protect my land rights?" is the question being asked in the cocoa groves of Ghana, the highlands of Ethiopia and the pasturelands of Tanzania. Across the continent, a land grab is under way. Governments take small farmers' land to create enterprise zones. Customary chiefs reap fortunes from urban sprawl by getting rid of "tenants" to make way for residential development. In Cote d'Ivoire, local people seize land back from migrant farmers who thought they had bought it. And the commons - whether grazing, woodlands or wetlands - are being eaten away by enclosure, depriving the poorest people of their final resort when times are tough.
Land lies at the heart of social, economic and political life in most of Africa: it provides income and employment for the large majority. It also has great historical and spiritual significance, establishing identity and links with previous generations. Yet in Burkina Faso, young men are tearing up agreements made by their fathers and giving notice to long-standing tenants. Once, land seemed in inexhaustible supply, but population growth and market development are generating mounting competition, especially close to towns.
So land tenure is contested all over Africa. Women's rights are especially at risk, because most African societies are based on patrilineal systems, in which property rights are held and transferred through men. The spread of HIV/Aids has made women's position still worse: in widowhood, they may be evicted from their land by their dead husband's kin.
Property rights are often weak or unclear. Even in Britain, the trauma of moving house is often put on a par with divorce or bereavement. Imagine trying to buy and sell without a title deed. In West Africa, less than 2 per cent of land is held by paper title, and that is mainly in towns. Most people hold rights to land and property through social bonds with wider family or neighbours. Land registration is inaccessible to most of the population. When buying property in Ghana, for example, you must visit six different government offices, usually in regional capitals, which entails a long journey for those from more distant parts.
African governments have often muddied the water on land rights. Most inherited the powers established by colonial administrations over land, water and minerals. They promised, as custodians of national assets, to use them wisely for the benefit of the people. In practice, they have used them for patronage and power. From William the Conqueror through the 19th-century Emperor Menelik II of Ethiopia to Robert Mugabe today, grants of land have always been used to reward loyalty. If you are loyal, you can hope for preferential access to newly irrigated land, or to building plots on the edge of town, rapidly appreciating in value. Ordinary farmers can be turfed off land they have farmed for generations, with little or no compensation. In Sudan, for example, the government elite have seized Nubian land and underground water reserves for irrigated commercial farming.
The commons are especially important for poorer people, but everywhere they are under growing pressure, as privatisation and enclosure continue. In Mali, Mozambique and Ethiopia, community rights have been given legal protection, and local committees established to ensure good management. Formal legal rights of this sort are vital if the commons are to survive.
Many governments now recognise more formal registration of land ownership would make sense. It would allow them to levy land or property taxes - a basic form of revenue for local governments across the world but rare in most of Africa. It would reduce conflicts and encourage more leasing, renting and selling of land. It would give poorer people better protection from their more powerful neighbours. It would allow more Africans to raise capital through mortgaging their land.
But so far, land titling in Africa has rarely been successful. Sometimes, written registers are set up, but with no thought of maintenance. Consequently, the gap between written record and actual ownership yawns wider every year. Elite groups find it easier to get their claims established.
However, there are some rays of hope for poorer people. Smallholders in KwaZulu/Natal, South Africa hope to get their land mapped and registered to protect it from the greedy hands of the traditional chiefs. Ghana is planning "one-stop shops" for land registration based at district headquarters. In Tigray, northern Ethiopia, a simple village-based system provides certificates to farm households, confirming their rights to use particular plots. Farmers now feel more confident to invest in conservation of soils and planting of trees. The certificates can be traded, so that a widow unable to farm her land can let it out. Because the registration happens in the villages, it can be used more easily.
New technologies - computer databases, global positioning systems - may speed up the establishment of a publicly accessible record. But a complete record will still take decades. Napoleon, keen to tax land, started a full map and register of property in France - but it took more than 30 years to complete. Britain still does not have a full, publicly accessible land record. That is why village-based registration is probably the best way forward.
If Europe and North America do cut back on agricultural subsidies, giving Africans a better chance of selling their farm produce in western markets, land will become an even more valuable commodity. There is a growing interest in buying land not only for farming, but also as a speculative asset. Those who have made money in business or politics increasingly want to establish landed estates, for status as well as financial gain. There is every likelihood that poorer groups will lose out again.
The Commission for Africa has skirted round such issues, with a few scattered references to how providing more secure property rights would promote investment and growth. Yet there is much that aid donors can do to help: work with African governments, for example, to spread low-cost forms of land registration; strengthen farmer associations, civil society groups and media that can monitor land-grabbing; support university-level training in land administration; and put money into South Africa and Namibia to speed up redistribution of land to black farmers.
Camilla Toulmin is director of the International Institute for Environment and Development, London (www.iied.org )