Debate Over Eucalyptus
Eucalyptus has been under fire for quite a few years now. Farmers, agronomists, environmentalists and scientists have all condemned the planting of this species. In 1983, Karnataka farmers uprooted eucalyptus seedlings from forest nurseries. More recently, Chipko activists in Himachal Pradesh were arrested while trying to uproot more eucalyptus. Meanwhile, to aid the activists, environmentalists marshalled evidence to prove that eucalyptus was not good for afforestation. Those ranged against eucalyptus claim that it has an insatiable appetite for water, poisons the soil, drains the soil of all nutrients, and fails to provide green manure and soil stability.
Eucalyptus species from among the 500 kinds that are native to Australia have been spread all over the world during the past hundred years. About six million hectares in over 70 countries are now under eucalyptus, making it the most widely planted commercial hardwood. And, it is being planted because it prevents soil erosion, stabilizes degraded slopes and provides some cash income to the farmer.
While it is true that eucalyptus was used to dry mosquito-infested marshes in Italy, Uganda and Israel, it has not been conclusively proven that it is a “water-pump” that dries the land.
Scientists in Brazil, which has more than a million hectares under eucalyptus, confirm that 10 hectares of eucalyptus consumes less water than the same area under natural forests. Several trials in Australia have proved that eucalyptus is the most efficient utiliser of scarce water – it controls the stomatal opening according to the availability of water.
Perhaps the criticism should be directed, not at the eucalyptus plant, but at the way it has been popularised. “The problem in Australia is not the same as in Asia,” says Ian Peter of the Rainforest Information Centre, “In Australia, eucalyptus has adapted to the soil and environment. It is a good tree. But in Asia, monoculture planting has ruined its reputation.”
The problem is that eucalyptus, the world’s fastest growing tree, is being planted where rich tropical forests once stood. No single tree can be expected to replace such a diverse tropical canopy, but no other tree can grow as fast as eucalyptus. Thus, the dilemma: do you want reforestation and tree cover now, or do you want to wait for decades for the tropical forest to regenerate?
In the eucalyptus debate, a war has been waged before the problem has been understood. Technical arguments are being confused with social implications. Some environmentalists have relied on half-baked data and taken emotional stands. As a result, the reputation of eucalyptus has been sullied and it will not be easily salvaged. At the very least, we should take note of what the Australian forestry expert K.G. Eldridge says, “Eucalyptus has existed in Australia for 20,000 years without any ecological damage.”
Eucalyptus being a sturdy, multipurpose tree species that grows and matures faster than others is in itself, a great advantage in many locations. We cannot just start calling eucalyptus names. What is now needed is detailed research to clearly indicate the advantages and disadvantages of eucalyptus.
~Sudhirendar Sharma is with the Energy and Environment Group, New Delhi.
By Third World Network
Eucalyptus planting is a major component of so-called social forestry projects intended to improve human welfare and the environment. In reality, scientific evidence and the experience of grassroots communities has shown eucalyptus to be disastrous for the environment. It has adversely affected the water, soil and agricultural activities of poor communities. Here’s a brief description of the major problems caused by planting this alien species.
Natural forests have been destroyed to make way for eucalyptus. In Karnataka, for example, under a huge World Bank social forestry plan, forests that had provided the basic needs of villagers for centuries, were cut down to make way for eucalyptus plantations.
Eucalyptus trees normally have deep roots which suck up too much water, depriving the land of vital moisture. This inhibits the growth of other native plants. Trees growing in dry zones, on the other hand, have shallow root systems that spread out and efficiently extract moisture. Long-term experiments have proven that, where rainfall is less than 1000 mm a year, soil moisture and groundwater are severely depleted by eucalyptus plantations.
Biologists have found that densely planted eucalyptus reduces the biological diversity, because they shelter few indigenous animals or plants. They have also found that eucalyptus increases soil erosion, and is therefore, unsuitable for steep terrain.
Eucalyptus takes a lot of nutrients from the soil in order to sustain its fast growth. Compared to this high intake of nutrients, however, it returns very little to the ground through leaf litter. The species also increases toxicity of the soil, which inhibits seed germination and plant growth. This has the effect of reducing the potential yield of nearby crops. A Bangalore study confirmed that the toxicity remains for a long time, especially in low rainfall areas.
The cumulative effect of eucalyptus on soil moisture, groundwater, soil fertility and other plant life, ultimately leads to desertification. It, thus, threatens the livelihood of millions of farmers.
Because of its negative social and ecological effects, all plans for eucalyptus plantations must be scrapped. The World Bank should halt all its eucalyptus projects. Governments must heed the warnings of environmentalists and indigenous people, and stop the indiscriminate planting of eucalyptus.