Eucalyptus - boon or bane
We’ve have been discussing about a lot of environmental hazards, deforestation, ecological imbalances and various other challenges being created by rapid urbanization and some wrong decisions taken in past. But that shouldn’t be interpreted as, only negative things are happening across. There have been various positive moves as well. Thee have been many attempted afforestation efforts too.
But, as they say, we must learn lessons from our past; the same goes true with our afforestation efforts as well. Whenever things go wrong, it is the most important to analyze and understand, what went wrong and how it went wrong. The post mortem of the incidents could lead us to understand the chain of events, its repercussions and its translation in our context.
For example, for our attempts of afforestation – the most controversial subject has been the “Eucalyptus Tree”. Eucalyptus has been undoubtedly one of the most popular trees in afforestation, farm forestry and social forestry programs across the globe, but at the same time, what works for America, doesn’t essentially work for Australia, since the soil, weather, rainfall, climatic conditions etc. are different in different geographies.
Eucalyptus is known for some of its rare traits like its fast growing, quick adaptations to wide ranging ecological situations, several industrial applications and as means of livelihood for unprivileged have elevated it to one of the most desirable tree species for farm forestry and afforestation. In Australian weather, it has done a wonderful job. Eucalyptus plantation, made many marsh & swamp lands to become good for agricultural usage, but in Indian tropical weather would it be equally beneficial?
The subject was discussed at length and many studies were submitted and referred to during 21st International Congress on Irrigation and Drainage, held between 15th – 23rd October 2011 @ Tehran, Iran. There have been various other researches happening before and after the conference as well, and several of them have been listed in the reference section of the article as well. But it is important to understand that all these have happened to measure the after effects of a decision taken in past, though it would’ve been ideal if the studies were conducted first and the decisions were taken later. Let’s have look at one scientific research data submitted in the conference; Table 1. Reduction in bore well yields (lps) by Eucalyptus plantation
The table explains how bore wells had to dig deeper and how their yield got reduced in places within a radius of 3~5 kms from the eucalyptus tree plantations. Thus it is established by the details scientific study that eucalyptus plantation does cause depletion of the ground water level in spite of all its merits, and in this era of global warming, and rapid urbanization, the depletion of the underground water level could be quite dangerous.
As it sucks water from the soil, this can dehydrate the surroundings and due to its allopathic nature, it creates dominance over other plants and trees planted in the vicinity. Thus in a area, if we try to plant mixed species farming, the eucalyptus would take a lead and won’t let other species grow, on the other hand also consume the available water on and in ground to make it tough for other trees to dwell.
While the above demerits have been associated with the eucalyptus, we still can’t deny the fact that it is one of the fastest growing trees, is a good cash crop for industrial usages for industrial wood requirements, get ready in 3~4 years and needs least amount of care, adapts to the climatic conditions, is suitable even for dry climate / desert like / drought like conditions as well and still grows at a rapid pace.
Thus the merits & the demerits puts the decision making to a dilemma that whether or not it should be considered as the tree of choice for the afforestation needs and helping the farmer in growing a rapidly growing cash crop like tree. Here we need to understand that any fast growing tree would hamper other crops to grow, as it’ll be utilizing the available natural resources more than the other competing crops, thus if you need a fast growing tree this factor is unavoidable.
Secondly for the mineral content of the soil, when any tree grows, it utilizes the minerals in soil to grow and return it to soil by shedding leaves. This happens with eucalyptus as well, but as its dry leaves are used as biofuel for cooking, people pick up the dry leaves and the minerals aren’t returned back to the soil, so we can’t hold the eucalyptus responsible for this. So ultimately it boils down to just one demerit – the underground water level depletion.
So what’s the way out?
Is there any other tree, which has an industrial demand, be it firewood or pulp wood or ply board industry, which is rapidly growing, takes 3~4 years to grow to the desired size for cutting to feed the industrial requirement, doesn’t hamper the growth of the agri-cultivation and doesn’t hamper the underground water level?
If we can find out one such species of tree, it serves the purpose.
And the answer is poplar tree.
- ICID 21st International Congress on Irrigation and Drainage, held between 15th – 23rd October 2011 @ Tehran, Iran – IMPACT OF EUCALYPTUS PLANTATIONS ON GROUND WATER AVAILABILITY IN SOUTH KARNATAKA, by Mukund Joshi and K. Palanisami
- International Journal of Innovation and Scientific Research, 2014 – Effects of Exotic Eucalyptus Plantation on the Ground and Surface Water of District Malakand, Pakistan by Hazrat Bilal, Sobia Nisa, and Syed Shahid Ali, Department of Environmental Science, International Islamic University, Islamabad, Pakistan
- Australian Journal of Botany, 2006 – Impacts of tree plantations on groundwater in south-eastern Australia by Richard G. Benyon, S. Theiveyanathan and Tanya M. Doody , @ Ensis, PO Box 946, Mount Gambier, SA 5290, Australia.
- XII World Forestry Congress, 2003 held @ Quebec City, Canada – Studies on Soil Moisture Variations under Eucalyptus Plantation by Ram Jee Srivastava, Ashwani Kumar and K. Prasad
- CENTER FOR FOOD SAFETY | Genetically Engineered TREES: THE NEW FRONTIER OF BIOTECHNOLOGY, September 2013.
- The Silviculture of Hybrid Poplar Plantations, March 2000 – report studies, prepared and submitted by Keith D. Thomas, Philip G. Comeau, Kevin R. Brown, from B.C. Ministry of Forests Research Branch, P.O. Box 9519, Stn. Prov. Govt. Victoria, BC V8W 9C2