Three years ago, the state government of Tigray banned farmers from planting eucalyptus trees on cultivable land. It feared eucalyptus would damage the soil, deplete water supplies, and displace food crops. While the government allows farmers to grow eucalyptus in community woodlots and in wastelands and hillsides, it limits the timber they can harvest for sale.

The case of Tigray once again raises the thorny issue of the merits and dangers of fast growing exotic trees such as eucalyptus, acacia, and teak. After a flurry of press reports and publications in the 1980s this debate has died down in recent years. But the possibility that carbon credits may become available for tree plantations will almost certainly revive it.

’The Role of Trees for Sustainable Management of Less-Favored Lands: The Case of Eucalyptus in Ethiopia’ by Pamela Jagger and John Pender of the International Food Policy Research Institute provides a balanced review of the key issues as they apply to the Ethiopian Highlands. The authors point out that farmers can get high rates of return from planting eucalyptus to produce poles for construction and to make farm implements. They can get even more money if they also use the woodlands to produce grass for animal fodder and to make honey and beeswax – as many of them do. By providing a ready source of fuelwood, eucalyptus production allows farmers to use their animal manure and crop residues as organic fertilizer rather than for fuel.

Eucalyptus trees serve as windbreaks and reduce soil erosion. Few if any indigenous tree species produce biomass as rapidly and efficiently as eucalyptus. On the other hand, eucalyptus trees compete with crops for water and nutrients and may inhibit the germination and growth of certain crops. As critics frequently note, eucalyptus trees can negatively affect local water supplies. (Then again, so can planting indigenous trees species.)

Collective management of village-level community woodlots in Tigray works reasonably well, although municipal level woodlots are less efficient. Privatizing the woodlots would probably not yield large economic benefits and only makes sense if the villages themselves decide to do so. (For those interested in the relative advantages of community versus private woodland management, Berhanu Gebremedhin, John Pender, and Girmay Tesfaye have another paper titled ’Community Natural Resource Management: The Case of Woodlots in Northern Ethiopia’.)