Competing for fresh water with trees in Zimbabwe – Colonial gluttony upset Zimbabwe’s ecological balance


Crammed into reserves with poor soils and harsh climatic conditions unfailingly punctuated by seasonal droughts, the natives soon found themselves stuck in patches of growing wastelands. Grasslands mown into the soil by a disproportionate livestock herd; and trees axed for shelter and firewood; the balding landscapes were soon being scared by gullies, choking rivers with silt. For 50 years, pressure mounted – exponentially. By the time the small southern African country found independence in 1980 some communities in the native reserves were burning dung, breaking the already poor nutrient cycle, to prepare meals. The situation was desperate. Cattle herd, the natives’ most valuable possession was soon limited to only four per household the rest sold off, with a flooded market, at a pittance. Indigenous trees had failed to sustain the growing need and were not an option in the country’s afforestation drive. It was hard to ignore the eucalyptus option. “The most practicable solution is to plant quick growing trees to provide local fuel and pole needs,” noted the rural afforestation division of Forestry Commission of Zimbabwe (FCZ) in a mid-eighties ‘Planting and managing woodlots’ booklet.

Of particular interest in their reforestation drive were three types of eucalyptus – grandis, tereticonis and camaldulensis which the booklet argued grew 15 to 20 times faster than indigenous tree species and had a further advantage of shooting from the stumps after each harvest. The nation was told that they would also be able to commercially exploit the trees after about six to eight years but within two years the trees would be available for firewood and fencing. Only one point appeared to threaten to blemish this saviour tree – that ‘no site should be chosen which is within 30 metres of a watercourse or vlei owing to high water use of these trees and the inadvisability of cultivating along water courses.’ Otherwise in the promotion of the species no unwanted trade-offs were even hinted on. All concern was only the success of the plant, with recommendations for it to be treated as a crop and be allocated the choicest lands with good soil depth and even in need of fencing to protect them from livestock as well as weeding to save them from rats! This otherwise delicate environmentally friendly panacea to restoring Zimbabwe’s ecological balance needed all the protection it could get from its tenders. Eucalyptus grandis was recommended for annual rainfalls of over 700 millimetres; eucalyptus tereticonis between 600 and 1000 millimetres; and eucalyptus camaldulensis for 500 to 600 millimetres with the booklet noting that no eucalyptus can survive in areas with annual rainfall below 500 millimetres. But this was only on paper. In practice the whole nation was being exhorted to establish eucalyptus plots.

The strategy to achieve nationwide appeal was simple but effective. Educationists were powerful popular opinion leaders, apt to be listened, and schools were reference points for both students and local communities. These became the first targets regardless of their rainfall pattern or the sufficiency of the annual average. By the late 1970 select schools were being supplier with eucalyptus seedlings for the plots, note some senior Ministry of education, Sports and Culture officials who are not authorised to speak to the press. “I remember at our school we even converted a cotton field to a gum plot. We initially were receiving seedlings and later were taught to harvest seeds, treat them and raise our own nurseries. I even planted some of the seedlings I had raised at school back home when l was still in primary level,” he said. A skill he say he still has and can use. He however notes that eucalyptus was in their case being promoted to provide fuel rather as a crop for the sale of its poles. Later, says Oswell Marange Manicaland province’s acting Deputy Provincial Education Director, schools were being asked to enter into competitions for the establishment of these woodlots and the plant of choice was eucalyptus all this was with the clearance from the MoESC Permanent Secretary. Nothing has been communicated to the ministry with regards to their long term impact or if they were not recommended for any particular regions, he said. With time, he added, schools were planting the trees to commemorate the national tree planting day set for December.

Community, misled by their trusted gatekeepers were soon in a flurry duplicating the examples of their local schools with little regard for distance from water sources living them competeing for underground water with the thirsty wood. The tree is also being used as replacement vegetative cover even along water courses. Otherwise there has never been an alternative species for such purposes. Very little is known about the other side of this thirsty wood. And there is yet to be a voice heard disapproving it for being water aggressive across the country for depleting the water-table. One educationist at Mafararikwa primary school about 100 kilometres west of the eastern border town of Mutare, an area in the country’s region 4 with an average annual rainfall of 400 to 450 millimetres and sandy loamy soils, said it would be rare to find a school without a eucalyptus plot. “Unless if it’s been recently built, but then plans will be in place to establish one anywhere you go,” Asani Ali said. Even urban schools always find space for these plots. That this native Australian tree species is so water aggressive that it was used to drain swamps to manage malaria in Algeria, Lebanon, Sicily, across Europe and in California, and is blamed for the continent’s lowering water tables is news. Even Forestry Commission Manicaland Provincial Forestry extension Manager, Phillip Tomu says his organisation does not know of any research that has shown the long term impact of eucalyptus plantations or that they can deplete ground water reserves. Of over 70 schools visited in Mutare Rural district, just on the leeward side of the eastern highlands, in areas that fall under region 4 all had a eucalyptus plot. But even at this cursory glance, there is an abundance of evidence proving that eucalyptus plantations, even on a relatively small scale, impact heavily on water resources. If only someone paid attention.

Wells are running low on water and some had to be sunk deeper. With an ever green tree sucking water throughout the year while it has seasonal droughts most of the people contacted in the district strongly feel the lowering water tables should be blamed only on poor rainfall. According to World Rainforest Movement (WRM), Kenyan-based International Centre for Research in Agroforestry (ICRAF) raised alarm on the “thirsty” nature of eucalyptus in August 2006, during a World Water Week meeting in Stockholm, in a region with an annual rainfall of between 1200 to 1800 millimetres even arguing that, “Eucalyptus alone can consume most of this water. Therefore in watersheds with average rainfall below 1600mm, it is prudent not to plant evergreen species such as Eucalyptus or pines. The Director General of ICRAF, Dr. Dennis Garrity, WRM says, noted that eucalyptus can have destructive effects on the environment because of its high water needs, and says that its widespread adoption across Africa had reduced the water table. But the lack of protest against eucalyptus in Zimbabwe, despite even lower rainfall, is deafening. After nearly two decades of research at its Machakos Research Station, ICRAF provides ample evidence on the issue and concludes that fast-growing evergreen species can quickly draw significant quantities of water from below-ground, raising serious concerns about their impact on landscapes. Tree species with water requirements that exceed available rainfall as they draw upon other water sources, can produce large negative trade-offs for other local water uses and for downstream water users.

It also produced a video that seems never to have reached Zimbabwe inspite of the close ties the countries have which provides figures on water usage, stating that one single 3-year old eucalyptus “drinks” 20 litres of water per day. During the following years, consumption exponentially increases and at age 20 the tree will “drink” 200 litres per day! Most importantly ICRAF’s findings counter one of the main arguments used by promoters of fast-wood plantations, which says that there is “no scientific evidence” proving that such plantations deplete water resources. The argument that there is no evidence for an organisation like Zimbabwe’s Forestry Commission may be untrue. Back in 1969, as a student of forestry, this writer’s father remembers farmers in Mteo, near a small town called Mvuma in central Zimbabwe, complaining of streams drying up and disrupting their operations. They were blaming the Forestry Commission run college’s eucalyptus plantations which sat at the head of the streams. These farmers’ complaints were never regarded or fully investigated. Even with so many schools, among many institutions and individuals, having planted the water aggressive tree monitoring their interaction with the local ecosystem might have sufficed.

An employee with one local non-governmental organisation which recently even invited senior government officials to include Forestry Commission officials and another government department, Environmental Management Agency (EMA) to plant over 100 trees te majority of which were eucalyptus in Mutare Rural said it was embarrassing to realise that “we were actually worsening the situation for the locals while we did so feeling we were actually being helpful.” Tomu while acknowledging the continued planting of eucalyptus however says their use was initially intended as a stop gap measure as there was only two options to provide alternative sources of fuel or provide a fast growing exotic tree species so as ease pressure on the indigenous forests so that they can regenerate naturally. In reality the nation never grew out of the need for the use of the thirsty tree; it is even now being planted against the recommended conditions for their optimum growth with the effect of many plantations in Mutare Rural even being stunted. EMA officials on the other hand point to Forestry Commission for any enquiries on eucalyptus arguing that the tree does not lie within their mandate as they are concerned mainly with invasive alien species. Environment Africa, a local environmental organisation is against eucalyptus not necessarily because of their water table depleting qualities, which they have not looked at, but due to their invasiveness and tendency to subdue the indigenous plant species. The water guzzling tree is taking blame for drying out many water sources across the globe.


© 2012, Bernard Chiketo. All rights reserved. – The views expressed here are purely those of the author and not necessarily those of the publishers. – Newstime Africa content cannot be reproduced in any form – electronic or print – without prior consent of the Publishers. Copyright infringement will be pursued and perpetrators prosecuted.

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