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A dry trech running through aeucalyptus groove. In 2006 we used to
play on the damp swamp but now its dry | |
Ever since it was discovered more than two centuries ago in Australia by European explorers , eucalyptus have been extensively grown globally.
Currently there are above 4million hectares of the species in over 80 countries worldwide according to Dr. Richard Matsekele of the Zimbabwe Environmental Research Institute.
With the rise of eucalyptus popularity controversy have also surrounded the specie.
In 1913 a proclamation in Ethiopia akin to Hon. John Michuki, Kenyan Environment minster, was made to oppose the species thirst for ‘drying up rivers and wells’. The directive wanted all standing eucalyptus trees to be replaced by Mulberry tree.
The campaign never materialized.
Eucalyptus still remains as feature in Ethiopia after 115 years of being introduced by emperor Menelik II for it fast growing nature to curb deforestation for wood fuel.
About three months ago, Michuki gazette the order of uprooting and prohibited planting of eucalyptus in watersheds and along rivers. Supporting the move the minister said the species negatively affects wetland environment.
Michuki exercised the power under section 42(3) and 147 of the Environmental management act which promotes the sustainable use of water resources.
Apart from Kenya and Ethiopia a move to control eucalyptus growth has been instituted in Australia, Brazil and South Africa while its negative effects have been felt in Madagascar and Zimbabwe.
Two questions to ponder is if the Michuki’s ban can be implemented, Secondly the effect of eucalyptus on the environment.
But firstly let’s see the rise of eucalyptus.
The match against indigenous forest. “When you go into these monoculture plantations, they look like dead forests because it is only eucalyptus. You don’t see birds, butterflies, other trees, animals- anything other than them because they don’t allow any other growth.” Nobel Laureate Prof. Wangari Maathai, founder of Green Belt Movement, at second World Congress of Agroforestry in Nairobi recently.
According to Maathai eucalyptus and other foreign species have replaced indigenous African species.
The main reason is that eucalyptus are fast growers and depending on use start maturing at six months. They regrow when chopped from the root. In addition their high quality timber is used for timber, ornaments and pulping. The species also provide fencing post and building material.
In industries, the eucalyptus oil distilled from the leaves manufacture food supplements like sweets and cough drops.
Prof. Wangari Maathai insists that these benefits should not be overtly promoted over the environmental issues.
“As we continue to plant eucalyptus on watersheds, we will continue to experience water shortages and it will even become a bigger problem as climate change hit us.” Said Maathai.
The problem is experienced in Madagascar where bio diversity is threatened by the species replacing the country’s original native forests. An example is the Andasibe-Mantanda national park.
Scientist against the indigenous forest conservation argue that the over 700 species of eucalyptus are adapted in different environments worldwide, thus, each specie negative effects should be accessed separately.
Conversely, Prof. Maathai, who won the Nobel Prize for her tree planting campaign, insists that if the trend is not reversed then they will consume a lot of water and dry up water sheds.
Not worth it. Their advantages aside, planting eucalyptus is not worth it.
In South Africa the nectar from eucalyptus provides high quality honey for bee keepers.
However, they became invasive by their water sucking capabilities of drying up wells. And by releasing chemicals in soil which kills native competitors.
Through transpiration the specie draws large volumes of water from soil which drys water towers.
Interestingly the effects on watersheds can not be permanent since eucalyptus roots only reach 2.5M underground. Through rain and irrigation the effects can be reversed though Biodiversity destroyed is irreversible.
Although it destroys the ecology, the ‘water sucking’ ability is used to reduce soil salinity and prevent malaria by draining swamps which breeds mosquito larvae habitat as is happened in Algeria, Sicily and California.
On the other hand their fast growth helps the specie to act as wind breakers and reduce soil erosion.
Eucalyptus negative effect on environment is not worth it although its fast growth can match the demand for wood fuel and other needs arising from population growth.
According to Food and Agricultural Organisation (FAO) with only a hectare of forest planted for every ten hectares cleared, exotic species like eucalyptus remain an alternative because of it alternative uses.
The species too can be harvested as early as six months depending on the use for either poles or timber.
With adverse effects of drought on crops, livestock and humanity causing economical and sociological problems, Michuki directive is timely. The changing weather pattern makes rain unpredictable creating a need for water conservation.
Economic sectors adversely affected by drought are tourism and tea production, which Kenya is the leading tea exporter in the world.
The Kenya Tea Development Agency which produces three fifths of Kenyan tea has its production reduced by 30% because of drought according to its managing director Lorionka Tiampati.
The effects of drought are taxing the economy calling for the need to conserve water.
The only loop side to control of eucalyptus on watersheds is that the minister’s directive under Environmental and co-ordination act was repealed by act no. 5 of 2007 under licensing laws by the parliament.
This is according to Mark Oloo, environmental lawyer with Institute of Law and Environmental governance.
No matter the economic gain of eucalyptus, their negative effects on environment cannot be overlooked as notes Prof. Wangari Maathai:
“Eucalyptus is good for the beauty they offer but consume a lot of water when planted along rivers and around wetlands and watershed.”
