Eucalyptus Cultivation

I have recently made several postings on the Eucalyptus Tree and its cultivation in the Tiruvannamalai District. There is no doubt that the Eucalyptus is a fantastic tree with a host of ayurvedic properties and benefits – but perhaps it would have been better to have left the tree in its native Australia and Tasmania. Already there are several Eucalyptus plantations around Samudram Lake, (south of the Hill) which is probably not a good decision considering severe water shortages often experienced in this area.

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"The recent move of the Tamil Nadu Forest Department to reintroduce large-scale cultivation of Eucalyptus trees in the State invites stiff resistance from environmentalists on the ground it would create ecological imbalance.

Experts have raised concern over the extensive cultivation of this species. “Monoculture of Eucalyptus cannot be recommended. If the intention of the Forest Department is to increase forest cover in the State, it should plant indigenous species of trees and herbs and maintain the bio-diversity of the region,” said a representative of the Tree Foundation. In a study on ‘Eucalyptus in India,’ it was pointed out that extensive cultivation of Eucalyptus was introduced in the country in the 1960’s. Since then some of the States took advantage of the centrally sponsored scheme and raised Eucalyptus plantations by felling even moist deciduous forests.

The Forest Department wants to increase the forest cover in Tamil Nadu from the present 23,023 sq km (21.25%) to 33%. To achieve this target, it will have to promote social forestry on at least 20% of the total 75 Lakh hectares owned by them. “This project is to be carried out on privately owned land and trees will be grown like any other cash crop. Earlier the mass cultivation, was carried out on land possessed by the Government and hence there was an uproar against it,” said a representative of World Wide Fund for Nature.

Others believe that growing Eucalyptus in ‘vulnerable zones’ like arid areas, will destroy the hydrological balance of the region. The tree is water intensive and reduces water available for other species, effectively out-competing them. Particularly vulnerable are arid areas with annual rates of precipitation that correspond to the lower range of eucalyptus demand at about 700 mm.

Studies have revealed that in arid areas, the consequent suppression of other plant life, coupled with a high water demand, reduces soil moisture, preventing the recharge of groundwater and can reduce local water tables. This is exacerbated by a high transpiration rate indicative of the inefficient use of water. Being nutrient intensive, it creates deficits for other plant life, a process that is exacerbated by the low returns in leaf litter to the soil. It does not contribute to the long-term fertility of the soil, as other species might, resulting in an overall nutrient impoverishment of the soil.

Eucalyptus is toxic, due to allelopathic properties which inhibit the growth of other plants due to bimolecules released by it. The plant also is detrimental to soil micro and macro fauna."

[With thanks to G.G. Jens]

Eucalyptus - Tiruvannamalai District

The 7 acre farm in front of my house used to cultivate multiple rice crops throughout the year. Interesting to see that they have now planted Eucalyptus saplings throughout their land. There are numerous Eucalyptus plantations in Tiruvannamalai District, a number of which are located close to Arunachala. The Eucalyptus Tree which is indigenous (with a few exceptions) to Australia and Tasmania, has now been introduced throughout the world. Thinking of all the blights caused by the introduction of non-indigenous crops and animals made me wonder whether “Is local best”.

It seems that this is indeed a relevant question considering an ongoing insect threat which now exists in India caused by an insect pest which came in with the Eucalyptus Tree.

To read of problems in the U.S. go to ‘Letter to Federal Agencies Requests Investigation Concerning Public Health & Environmental Risks of Cryptococcus gatti’. The letter in part discusses “Cases of C. gattii disease have been increasing in number and also spreading geographically, along with the introduction of Eucalyptus species worldwide. C. gattii has been isolated from Eucalyptus trees in India, Spain, Colombia, Brazil, Paraguay, Africa, USA (California), Mexico and Southeast Asia”

In some parts of South India farmers are being encouraged to abandoned their traditional farms and specialise in extensive tree plantations. In this respect, environmentalists and international justice groups are voicing their concerns over proliferating tree plantations, as developing countries try to profit from a growing carbon trade. The India Tobacco Company claims to have stepped into the carbon sinks business in order to benefit village communities. For an interesting article on this subject which questions "Who really profits?" read: Indian tobacco giant turns carbon philanthropist

The next Arunachala Grace News, which will be sent out at the end of this month, has an article on the Eucalyptus and the many beneficial properties of the tree and its leaves. If you are not yet a subscriber, you can sign up (at the subscribe facility on the left margin of this site) for a free monthly Arunachala Grace newsletter sent direct to your inbox.

Eucalyptus

Insect threatens Eucalyptus

An insect, new to India, which is believed to have migrated from Australia, has started to damage large swathes of Eucalyptus plantations in South India. The insect is feared to pose a threat to an estimated 8,000,000 hectares (a hectare is 2.47 acres) of plantations. Eucalyptus is an important pulpwood species, which is widely used in paper and rayon industries. First reported in Malakampadin area in Tamil Nadu, the damage has now spread to neighbouring States of Kerala, Karnataka and Andhra Pradesh.

The Eucalyptus tree was introduced to Tiruvannamalai District in recent times and is now commonly found in the immediate surrounds of the town of Tiruvannamalai.

A local plantation of young Eucalyptus trees

Authorities first noticed the menace when they found parts of Eucalyptus trees in Andhra Pradesh forests damaged due to the insect. The insect is of a group which lays eggs inside tree leaves and stems and blocks the sap flow to the tip of the plants, causing shoots to droop and thereby affecting normal growth.

In 2000, the infection was first reported in the Middle East and thereafter subsequently spread to Mediterranean countries and northern and eastern Africa. Though no specific pesticides are available to kill the tree insect, research suggests early treatment can halt damage. It is recommended that as soon as the insect problem is located, one should prune or cut off the parts that are affected and apply systemic pesticides, which will go inside the plant and kill the insect.