Eucalyptus (Blue Gum) Trees: Are they good for our Environment and Climate?

This post was first published on Thursday, 02 Apr 2009 at 20:46hr.

The comments this post generated are also published below. You are welcome to share your thoughts on the same.

Indigenous Tree species

When I was growing up, there were very many tree species in my village. I am still under 30, but I had the chance to see many indigenous tree species in my village. But these have since disappeared.

As we continued to seek answers to adverse climate change, erratic rains and extremes in temperature, rain, snow, wind and other weather elements, it worth noting that many of the problems are undeniably man-made.

The Eucalyptus Tree

Blue Gum Trees

Last week, I took a long walk in my village and took photos which paint a really bad picture of the negative human effect on both the climate and our environment.

Everywhere I go, all I see is Eucalyptus or the Blue Gum trees. They are all over, and at first sight, you may imagine people have finally decided to plant trees enthusiastically. Unfortunately, the main reasons are largely commercial and for convenience. The trees grow pretty fast, provide significant timber and remain unaffected by dry spells.

Very tall Eucalyptus (Blue gum) trees

The Eucalyptus or Blue Gum tree is a fast-growing tree, that is cultivated throughout the tropics and subtropics including the Americas, England, Africa, the Mediterranean Basin, the Middle East, China and the Indian Subcontinent.  It is a good source of wood, its oil can be used for cleaning and functions as a natural insecticide, and it is sometimes used to drain swamps and thereby reduce malaria risk… [read more about the Eucalyptus on Wikipedia]

Environmental Impact

Young Blue Gum (Eucalyptus) trees

Researchers and environmentalists all over the world have derided the Eucalyptus tree for being an invasive water sucker.  This causes major problems for local ecosystems.

My Take

It is my considered opinion that we should stop planting these eucalyptus trees at this rate. I have personally decided to plant many species of trees, preferable indigenous species once the long rains set in.

Whereas large scale planting of eucalyptus trees is usually motivated by economic reasons, the climate change and environmental degradation that eucalyptus plantations contribute to can be averted. By simply planting less of these trees and trying out other species.

Let us all learn, share and foster change in our approach to the environment and the climate.

Comments:

i would appreciate very much if you emailed me documentation and links to online resources that would explain how the eucalyptus trees have a negative impact on the soils and water (their impact on the environment)

regards
- Anita

i believe that we encourage people to plant trees to increase our forest cover n we have to balance between indigeneous trees and commercial trees. if guys are planting eucalyptus trees to meet the need for timber what so wrong with that coz the trees will act as a wind breaker n bring more rain in as muc as it’s sucking water.

the main problem we have is tapping and conservation of rain water

- Robert

Robert,
Planting these trees commercially to meet people’s need for timber is alright. But the long term adverse effects are the problem here.
Let me give you an example: Using DDT to kill mosquitoes and alleviate malaria is alright too. Alright indeed, if we have absolutely no regard to what it does to the ozone layer.

Harvesting and conserving water should be done, but only in concert with efforts that seek to maintain or reintroduce an ecological balance. Dealing with eucalyptus trees is one such initiative.

- Pete

Very interesting post! I’ve read before that Eucalyptus is having a negative effect on soil conditions in much of East Africa.

Leguminous tree species on the other hand, can be used for their nitrogen fixing properties to help improve farmland, a method that I believe is beginning to be utilised in Kenya.

- Paul James

Thank you Paul and a warm welcome to Green Kenya.
The prevalence of these blue gum trees is a disaster waiting to happen.
I agree with you on the alternatives we may all want to consider. This should reverse much of the damage already done.

- Pete

I would love to get detailed research showing how eucalyptus negatively affects the soil. because i dont believe that it does

- Chris Chisanga

Welcome to Green Kenya Chris. Thank you for sharing your thoughts.
Eucalyptus trees actually impact negatively on the climate. I have personally seen it happen in my local area.
I’ll soon email you documentation and links to online resources that will hopefully explain to your satisfaction, how these trees have a negative impact.
Please note that the adverse effects are not only limited to the soil, the main problem is an ecological imbalance which eventually affects many other climatic and environmental elements.

- Pete

I’ve heard Prof. Wangari Maathai(Nobel Laureate) talk about how destructive the Eucalyptus trees are to the environment. This was during the World Environmental Day held last year (2008). I believe that what she said is happening in as much as the Eucalyptus is good for medicinal value and firewood, I don’t think we should encourage planting of this “destructive” tree. I’ve seen people planting it in Kajiado, Mt. Kenya region, parts of the Rift Vally -places that are currently desperate for water and the trees are drying up the water bed. More needs to be done and articles in the Media be sent to sensitise Kenyan’s on the adverse effects of this tree. South Africa is instead concentrating on growing Indegenous trees so as to maintain their water resources and save the environment, while us Kenyans are so money minded thinking how in 10 years we’ll pocket money for “POLES”. Food vs poles? Surely.

As Peter says, we need to deal with the Eucalyptus tree “menace”. Its drying up our water resources and causing adverse effects to the environment. Encourage planting of Indegenous trees and we then can have food and water security.
My two cents.

- Jackie Arkle

Hi Peter,
This is a nice debate. My view is that there is a reason for everything that is happening.

First, Eucalyptus is not ‘invasive’ say like ‘mathenge” or water hyacinth are.  Most of the trees you see anywhere have actually been planted.

Eucalyptus is prefered to other tree species because (1) easy to germinate and plant(2)grows fast (3)grows well in wide variety of climates and soils (4) can grow into tall big sizes (5)can be used in variety of ways including firewood, charcoal, electricity poles, building,and timber (6)often regenerates after harvesting. (This is not exhaustive list).

The above are some of the reasons a blanket condemnation of the tree species will not do unless there is an alternative tree that will satify most of the most important advantages of eucalyptus.  For example where I come from (Kisii) the issue of planting indigenous trees is almost out of question because land is scarce due to high population density. A poor family solely depending on less than one acre of land to survive will like to plant ten or so trees to provide them with firewood (they can’t afford parafin leave alone gas!)

Before you condemn and uproot eucalyptus give us the alternative for especially firewood and something to build our mud and thatch houses.

Regards,
A. N. (Andrew Nyakundi)

Dear Peter,

Can you send me the documentation and links to online resources that explain why this tree (Eucalyptus) has a negative impact on the environment. In my country (Colombia) and the area I live in (Northern part) they are promoting for the region a Silvopasture project were the tree that has been choosing to cultivate is the Eucalyptus and . Specifically, the species is the TERETICORNIS y CAMANDULENSIS.

Thank you,

Antonio

Am from the slopes of mt Kenya,kereita forest,Gatamaiyu-Nyanduma.
I support the extinction of Eucalyptus tree for its adverse effect on our environment. I also requst for collection and distribution of eco-friendly species of trees. I also wish to see the implementation of the 10% of tree coverage in our farms.
How can Green Kenya help in such a task?
Doing a Good job nature conservation.

- Benard Nganga

Well well well! I have a big  dispute on this! I was to write an article on Eucalyptus after interviewing some locals who plant this trees in the Rift valley province but this article caught my eye.
During my tour, I realized that most people plant the eucalyptus trees, pine, cypress and black wattle, they are so comfy with them this made me wonder why. Its a source of revenue to them to find out if it does affect their water catchment areas, they have not experienced that; The base of this is citing a piece of land and plant only trees, I caught up with a retired Forester who has an acre of eucalyptus trees and from his experience he loves the trees and seen no side effects of it he says even other trees have side effects. I thought the Kenya Forestry were in for uprooting the trees! Can sm1 explain this to me. In my on opinion Eucalyptus trees have side effects just like any other tree.

- Anon

Dear All,

I got some info on the following link which will shed more insight

www.taftz.org/USEOFEUCALYPTUSINAFFORESTATION.doc

For Me, I think with what’s going on in our country Kenya, we MUST do away with the Eucalyptus. The water bed levels have greatly diminished especially in Kajiado.

An alternate link is :

http://www.aracruz.com.br/eucalipto/en/download/eucalyptus_environment.pdf

- Jackie Arkle

Thank you guys for all your comments and thoughts.

Jackie, the articles you shared are much appreciated.

- Pete

Hi Peter. Please assist me with your email address. i wish to exchange some ideas with you regrding eucalyptus

- Lang’at Kipkorir

Hi Andrew,
I always hated going home during the months of april to june coz the entire place would be water logged. When my husband came up with the idea of eucalyptus for one acre of the land, i said why not. My trees are about 2.5 yrs now and they are beautiful, water logging has also reduced and I can now walk comfortably when i go home. My reasoning is, if the land is not being utilized and its not near a river bank, then why not? after all you can uproot the trees after harvesting if you want to use the land for something else.

- Christine Opiyo

i find this article rather biased and not informed by the extensive research in other parts of the world on eucalyptus especially in Brazil. please read the article on eucalyptus by Lima 1993

- Samuel Were

Dear All,

I have land in Kajiado, it has Black cotton soil.I’d like to plant trees that are sustainable and not harmful to the environment. Please advise what trees I should plant in an effort to make my 10% conservation. So far i’ve planted Grevillea as wind breakers as I want to put up an eco-home .

Keep the emails coming. I share the information with my friends.

Lets continue to conserve our environment and make Kenya a better place for our children and our children’s children.

Does someone have Prof. Wangari Maathai’s contact? It would be good to have her professional input in this blog. We also need to have this forum on Facebook. We can get more support not only regarding Banning the Eucalyptus trees, but also on suggestions on Indigenous trees .

Mubarikiwe.

- Jackie Arkle-Okutoi

Eucalyptus is one of the most cultivated commercial tree species. Much as it is, it is also the most condemned in Africa and other tropics. While it is a high water user, its adapted to dry conditions and able to regulate water intake depending on availability. It is not exceptional in affecting soil. Land previous under tea is not good for agriculture yet we are not advocating for uprooting of tea. What is needed is proper management practices and ecosystem management rather than blantant uprooting of trees in a wave of misconceptions

- Pius Mutinda

Dear All,

Here is Rodrigo from Brazil. I was looking for some online info about native Kenya trees species and I found this site… So, I got here and I think is really important to talk about this issue based on science and not just feellings and options. Here in Brazil we do have a lot of Eucalytus Planted Forests that we usually call “Green Deserts”. Based on our researchs, the evapotranspiration of Eucalytus  is almost the same of other plantation species around here. I am forestry student and I have here some numbers of brazilians researchs for you guys:
Amount of wather (mm) necessary for one year of plantation: Sugar-cane(1000-2000mm), Coffee (800-1200mm), citrus (600-1200) Eucalyptus (800-1200mm).
Comparison of wather consume between Eucalyptus and other plantation:  Potato 1kg/2000 liters of wather,  Sugar cane 1kg/500 liters, Korn 1kg/1000 liters and Eucalyptus 1kg/350 liters.
And there is a new research that proves that the evapotranspiration of our native forests (our atlantic and amazon forests) are the same of a planted eucalyptus or pinus forest. And most of that equivalence is because the percentage of interception (rain drops holded by the leaves) is bigger on the natives.
Sorry about my english… But I couldn’t pass by without leave my thoughts.
I think it is important and necessary specie for the economic and preservation of our natives. Here we harvest it with 7 years for paper and 10 years for timber… There is no native that could grow that fast and that quality for those proposes. For firewood here we use our native Mimosa scabrella (specie similar to the Acacia mearnsi)that grows very fast and has a good wood for fire.

Best regards,
- Rodrigo Chaves

Hello all
I also keep getting conflicting information about the suitability or otherwise of the Eucalyptus tree and their impact to the environment. I’ve done lots of reading from the internet and any scientific materials I’ve seen disagree with the theory that these tress can lead to a desert. As one write has written most of agricultural Kenya such as the central highlands, Kisii area have these trees yet they continue to receive substantial rainfall.
My question therefore is between planting  these trees and not planting at all which is better? We all agree native indigenous trees would be the best. But lets also appreciate people will mostly plant trees for economic gains. They are more likely to plant eucalyptus which grow fast and make money out of them. I’ve therefore personally planted thousands both for economic gain and to contribute to forestation of Kenya. Without scientific proof of how these trees affect the climate adversely, lets encourage everyone to plan and keep our emotions aside.
I would be glad to receive such research.

- Nderitu Kiarie

Fruitful Topical Exchange

There you have it my friends!

The above was a very engaging and fruitful topical exchange about this tree that continues to elicit mixed reactions the world over.

What are your thoughts?

We’d love to hear from you. Feel free to leave a comment below.