Kenya: A simple wasp adds a further problem to Eucalyptus

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Kenya is a semi-arid country and is classified among countries affected by chronic water scarcity in both its urban and rural areas. Within such context, the planting of eucalyptus trees appears to be suicidal. And it certainly is.

Less than 2 percent of Kenya’s total land surface is now under forest cover. However, its significance is enormous, since forests in mountainous areas shelter the headwaters of Kenya’s major rivers and exercise a natural regulatory control over the river flow. Without them, siltation and flooding will increase, affecting millions of Kenyans. The severe drought from 1998 to 2000 has been partially attributed to the country's disappearing forest cover.

Indeed, forests have been shrinking. Logging and conversion of natural forests into agricultural land can be identified as direct causes of deforestation, while there are also underlying causes including export-driven agriculture schemes, the liberalization process --that has put a lot of emphasis on the privatization of public land and forests resulting in the non recognition of customary resource tenure-- structural adjustment programmes increasing pressure to exhaust natural resources, political interests resulting in forest excisions by the government to buy political patronage.

To counter the problem, Kenya established significant areas of tree plantations during the 1970s and 1980s. However, much of the effort was geared to fast-growing alien tree species, which were planted in large scale projects by government and non-governmental programmes with the eucalyptus as favourite.

However, the negative impacts of such plantations --which worsened along the large-scale pattern-- soon became evident for the people of Kenya. In fact, impacts on water became so obvious that one of the Kikuyu names for eucalyptus (munyua maai), means the "drinker of water". Even some government officials, like the District Forest Officer of Kakamega, Ms Monica Kalenda, have acknowledged that planting of eucalyptus trees in water catchment areas and along rivers had led to drying up of many feeder rivers in the province. There are areas on the outskirts of the Kakamega forest where the trees have virtually led to the drying up of many streams.

To make matters worse, an exotic pest, identified as the gall-forming wasp, Blue Gum Chalcid (Ophelimus eucalypti), is currently threatening eucalyptus trees in Western Kenya. The Kenya Forestry Research Institute (KEFRI) said the pest has badly damaged young trees and nursery seedlings in parts of Vihiga, Busia and Kisumu districts. The pest's origin was identified as Australia, the home of eucalyptus. It has also been recorded to attack eucalyptus species in other countries like Morocco, Iran, Israel and Italy.

In sum, monoculture eucalyptus plantations not only impact on the environment but are themselves prone to pest infestations resulting from them being large-scale monocultures. The "technical solution" to the problem would be the widespread spraying of pesticides, which would further impact on people and the environment. The real solution will obviously imply a totally different approach to tree plantations, based on the locally-agreed upon use of a diversity of species having positive social and environmental impacts.

Article based on information from: “Pest Alert”, Kenya Forestry Research Institute, ; “Kefri identifies pest affecting Eucalyptus in western Kenya”, Kenya Forests Working Group, ; “Residents cautioned against Eucalyptus”, Francis Nzaywa, East African Standard, April 10, 2003 ,