When Kenyan Nobel Peace Laureate Wangari Maathai launched in 1977 the Green Belt Movement – promoting the planting of indigenous trees in forest catchment areas and riparian reserves, private farms with high community access, and public spaces to preserve local biological diversity – she was wary that that the introduction of exotic plant species can have a severe effect on the balance of the ecosystem.
Professor Maathai called for a ban on commercial eucalyptus tree plantations in the country on the grounds that their high rate of water demand was contributing to the depletion of water.
Not only Maathai is aware of the impact of eucalyptus plantations on water: “munyua mai” (water guzzler) is the name given by Maathai’s native Kikuyu to the tree.
In 2002 fast growing species Eucalyptus grandis and Eucalyptus camaldulensis had been introduced to Kenya from South Africa and planted in great numbers everywhere. Some years later the effect of eucalyptus on water was felt when water sources began to deplete.
In 2009, environment minister, John Michuki, issued the directive to cut down eucalyptus tree species growing near water sources in an attempt to lessen the impact of the drought that was ravaging the country.
However, Minister for Forestry and Wildlife, Noah Wekesa, has launched guidelines for farmers who want to plant different species of eucalyptus.
Maathai has accused Wekesa of failing to curb eucalyptus in highlands despite the adverse effect of the trees on the soil, the water cycle, biodiversity and local vegetation. She said the government should discourage all species of eucalypts in highlands and water catchments.
Wekesa said eucalyptus fulfils local timber demands because it grows fast but Maathai argued that there are alternatives like native bamboo, which grows very fast, takes in little water, holds soil together and stops erosion, and has proved very useful in many countries where it is widely used for construction besides food and medicine.
Standing far apart from the large-scale tree monoculture model, Maathai had already stressed the need to “expand existing proven and integrated tree-based practices such as combining conservation agriculture with agro forestry — what we might call "evergreen agriculture" (See WRM Bulletin 147). This would make it possible to achieve environmental benefits and sustainable food security and livelihoods. To achieve this will need sound decision support mechanisms from researchers — supported by policymakers for effective implementation — that builds on knowledge, partnerships and capacity.”
Article based on information from: “Maathai Wants Bamboo to Replace Eucalyptus”, John Muchangi, 27 April 2011, AllAfrica, http://allafrica.com/stories/201104280123.html