Pros and Cons of Eucalyptus Tree Plantation
Experts Reject Misperceptions about Eucalyptus Plantation
Key Points about Eucalyptus Species
- Eucalyptus was introduced in Indian sub-continent by Tipu Sultan in 1790.
- Eucalyptus has more than 700 species worldwide and native to Australia.
- The eucalyptus tree is native to the Australian continent and has been introduced to the other five continents due to its ability to grow quickly.
- In Pakistan it was introduced during the time of the British but concentrated research on its species performance was carried out at the Pakistan Forest Institute (PFI) since its establishment at Peshawar by eminent forest officers and research scientists.
- In Australia, there are about 700 species of eucalyptus but in Pakistan, only five species were introduced, either for their fast growth or for their aesthetic value.
- Eucalyptus camaldulensis, its scientific name, is the species that has been planted extensively as roadside and canal-side plantations, as well as compact irrigated plantations in all the four provinces.
- Eucalyptus has better Water Use Efficiency compared with Shisham and other commercial broad-leaved species.
- Eucalyptus has ease in raising, planting and management.
- The low wood rates of eucalyptus in the 1990s made it unpopular as a farm forestry tree and negative propaganda was started against it.
- It is blamed for high water consumption and lowering water table which is more like a myth than reality and needs to be investigated thoroughly on scientific lines including other variables responsible for water depletion.
- Due to the controversy, provincial governments banned its plantations. However, the bans were lifted after some years due to pressure by farmers when its demand was created in coal mines in Balochistan for pit props.
- Eucalyptus intercepts less water as compared to Conifers, Acacias and other major broad-leaved species i.e., more water reaching to the soil.
- Eucalyptus reduces soil erosion as well as surface run-off.
- Eucalyptus seedlings consume comparatively less water than Tamarix, Dalbergia and Morus seedlings.
- Eucalyptus has higher water use efficiency (0.48 lit/g) compared with conifers and broad-leaved species.
- Eucalyptus camaldulensis should be planted as a mixture with other tree species.
- The evapotranspiration rate Is highly regulated by the Eucalyptus as and when moisture is available to the plant.
- Eucalyptus has provided ample opportunities to reduce pressure on natural forests which are highly desired for the purpose of watersheds and environmental benefits.
- It is the cheaper commercial raw material for wood-based industries and household fuelwood.
- Eucalyptus is a source of Income generation from depleted lands.
- Another benefit of eucalyptus is wood production for timber, firewood and pulpwood. Its fast growth also makes it suitable as windbreaks. Plus, the eucalyptus plays an important role in reclaiming water-logged and saline areas and also used in reducing malaria by draining swamps, which provide a habitat for mosquito larvae.
- Furthermore, eucalyptus oil is used for cleaning, deodorising and in food supplements, especially sweets, cough drops, decongestants and insect repellent. The nectar of some eucalyptus produces high-quality honey. Being an evergreen forest tree it consumes carbon dioxide and releases oxygen. Therefore banning eucalyptus plantation was not a wise decision.
- It is important to note that the allelopathic effect is because of chemicals released from eucalyptus leaves after disintegration. The chemical inhibits the growth of ground vegetation. Its compact plantations do have allelopathic effect in areas with less than 400 mm annual precipitation. However, linear and mixed plantations have a little allelopathic effect on ground vegetation.
- Compact and pure plantations do affect biodiversity. Therefore, the eucalyptus shouldn’t be planted in natural forests – and if planted its composition should not exceed five per cent.
- It does exhaust soil nutrients; one must note that all fast-growing tree species use nutrients and water for their fast growth. Eucalyptus foliage and bark contains a large number of nutrients, and the retention of foliage and debarking of logs at the felling site is a good management practice to keep the site fertile.
- Eucalyptus should not be planted on the farmlands if its returns are less than the reduction in the crop yield but if the return from its wood compensates the reduction in crop yield and gives extra profit then it can be planted on farmlands. It is true that eucalyptus has oil in its leaves and too much litter found under compact plantations can create forest fires. However, this has been reported from other countries but not Pakistan.
- It is also true that eucalyptus takes shallow groundwater, but does not affect deep groundwater that has more than 25 ft depth. Since it has a spreading root system and tape root is not deeper than 20 ft it does not affect the deep water table. Studies have shown that the eucalyptus’s annual water consumption is about 1000 mm and if the rainfall is more than 1000 mm it will not affect the water table. If the precipitation is less than 1000 mm, it will tape groundwater where the water table is shallow.
- Eucalyptus should only be planted where it is required. On barren lands, it should be planted to increase the forest cover. It can be planted as roadside and canal-side plantations. However, it should not be planted in the watershed areas and also not in the natural forests because it may affect biodiversity. It should not be planted near buildings as its surface roots penetrate the foundations and damage them.
- Nothing competes with the eucalyptus as it easily grows in the plains of Punjab, Sindh, Khyber Pakhtunkhwa and Balochistan. It can also be planted in the scrub zone under rain-fed conditions. For pit props and the chipboard industry, eucalyptus can be managed on a 5-6 years rotation, which can give high profits to the farmers. It is now being planted on sand dunes in districts Mianwali and Khushab by farmers at a large scale to make sand dunes productive.
- In the irrigated areas of the country, the eucalyptus will prove to be a good agroforestry tree and increase the income of the farmers – since it now has a good market.
Forestry experts from across the country on Wednesday took stock of the benefits and harms of the plantation of eucalyptus, especially in the wake of billion tree afforestation drive in the province.
They were speaking at the inaugural day of a two-day national seminar.
The seminar on “Pros and Cons of Eucalyptus Plantation in Pakistan” was organised by Pakistan Forest Institute (PFI). Forest, environment and agriculture scientists, representatives from wood industry and civil society from all over the country are participating in the seminar.
Special Secretary Forest, Environment and Wildlife, Zariful Maani, was the chief guest on the day one of the event.
PFI Director General Hakeem Shah was also present on the occasion. Around 15 experts delivered presentations on the issue and discussed every aspect of the subject matter.
Zariful Maani said that the billion tree afforestation drive in Khyber Pakhtunkhwa proved a massive success as nearly 1.2 billion trees were grown in the province during the past few years. He said the success of the tree plantation drive had gained applause at national and international level.
Every kind of trees was planted and conserved during the drive, he said, adding, a good number of eucalyptuses were also grown in various parts of the province, which drew some comments, especially in media.
Therefore, the department decided to hold a comprehensive research-based event to discuss the benefits and harms of eucalyptus wherein proper recommendations could be worked out, he said.
The recommendations, which would be given after the completion of all the presentations today (Thursday), would be fully implemented in the 10 billion tree afforestation drive across the country under ‘Green Pakistan’ project, he added.
He said that both field researchers and academic experts have been invited to the event so that the scientific and technical aspects of eucalyptus plantation could be discussed and the negative perception about it could be overcome.
Hakim Shah said due to its fast growth and good marketing, eucalyptus has become very popular specie among the farmers and its demand both on farm and market has increased manifold. However, certain misperceptions have also been attached to it.
In view of those misperceptions and its huge plantation across the country, the PFI organised the seminar to know the actual facts by scientifically analysing the issue and provide specific recommendations to the government as well as farmers.
Some of the speakers rejected the misperceptions attached with eucalyptus plantation. They said eucalyptus was Australian specie, which has been introduced to the five other continents.
It has the capability of growing very fast and it is the tallest flowering tree, they said, adding that in Australia, there are 700 species of eucalyptus, while only five of its kinds are found in Pakistan.
The speakers said that eucalyptus was good for plantation on water-logged and saline lands and it was adjustable to wastelands. “Eucalyptus provides feed, thermal cover, perching, roosting and shelter to birds and animals,” said Mohammad Ali, extension specialist, PFI.
Mohammad Ali Bajwa said it was not true that eucalyptus consumes much more water than other plants. He said it was not the lone reason for lowering water table. Other species of trees and agricultural products consume more water than eucalyptus, but the main reason behind water depletion was the increasing number of tube-wells and water pumps, he added.
Other speakers said that the benefits of eucalyptus plantations were much more than its harms. They said that no specie was harmful. However, proper management should be ensured during plantations and special attention should be focused on the site suitability for different species, which is the essence of forestry.
Dr Ghulam Akbar was the resource person on the occasion. Dr Gul Daraz Khan, Chairman, Water Management Department at the Agriculture University Peshawar, Dr Ghulam Ali Bajwa, Director Sericulture, PFI, Dr KM Suleman from the wood industry, Dr Azhar Ali Khan, Chief Conservator Forest, Malakand, Safdar Ali Shah, Chief Conservator, Wildlife, Khyber Pakhtunkhwa, Tehmasip Khan, Project Director, Billion Tree Afforestation, Malik Segheer, Conservator Forest, Watershed Circle, Ali Gohar Khan, Director Forest Research, Ghulam Mustafa Nasir, Forest Products Division, Tanveer Ahmad Qureshi, Biological Research Division, Dr Iqtidar Hussain, assistant professor Gomal University, Dera Ismail Khan, Anwar Ali, forest mensuration officer, and others presented their papers on the occasion.
By Yousaf Ali
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