An exotic plant introduced here in the 30s has been drying up the soil and causing environmental hazard
The idea that trees can help limit global warming is enshrined in the 2015 Paris Climate Agreement, with most countries including forest expansion as part of their plans to reduce emissions. It is universally agreed upon that planting trees is the least expensive and perhaps the easiest way to offset carbon.
Tree planting is an instrumental action to save the Earth which is without any doubt a cost-effective Nature Based solution to tackle issues like climate change. This year the forest of Sundarban once again saved us from the impact of Cyclone Amphan, 2020 just like last year’s Cyclone Bulbul and it has been doing so for many years. Also, people in all communities already have the skill, capacity, and resources to do tree plantation.
However, people take this opportunity and plant many exotic trees intentionally or unintentionally such as eucalyptuses by clearing the forest to meet the needs of the industries across the country. One of the biggest problems with eucalyptus is the negative impact on the environment because its rate of transpiration is awfully high. Eucalyptus has more economic value however, the same traits that make eucalyptus attractive for planting such as rapid growth compared to other trees, also make them potentially invasive.
The eucalyptus tree originated from Australia and was introduced to our country in the 30s. If we look back into history, in 1930 this tree was haphazardly introduced in eastern Bangladesh by the tea estates as an ornamental tree (Davidson and Das, 1985). Back in 1995, when the bad effects of eucalyptus were detected by the Ministry of Environment and Forest department (MoEF) they excluded eucalyptus from its afforestation program and informed the people about its effects on the environment (The Financial Express, 2018).
Sadly, it was too late because the plantation practice of eucalyptus was out of control as nurseries around the country produced and sold the saplings in huge quantities. This exotic plant provides more money because of the timber and as it grows in a very short time compared to other trees. In some cases, most of the people are aware of the adverse effects of the tree, but they grow and sell it for the sake of better business.
Presently, eucalyptus plantations are so widespread that they can easily be found in large numbers on almost every yard, premises of offices, by the roadsides and along railway tracks especially in the Northern parts or Bangladesh (Dinajpur, Thakurgaon, Panchagarh, Rangpur, Nilphamari, Gaibandha, Kurigram and Bogra), putting the environment in grave danger (Khan,2018).
Eucalyptus contributes to drying through transpiring water 18-20 times more than any other tree in the country. If eucalyptuses are allowed to grow around a natural reservoir for about 10 years at a number of 10 percent of total trees, water level is likely to reduce by 20 percent (Rahman,2016).
Even the leaves of this tree cannot be easily decomposed and cause harm to the soil. Experts say that pollen emission from the eucalyptus flowers is also high, which may cause respiratory problems to humans.
Growing eucalyptuses in low rainfall areas (Northern Part of Bangladesh) may cause adverse environmental impacts due to competition for water with other species and an increased incidence of allelopathy.
When Eucalyptus is grown as a short rotation crop for high biomass production and removal, soil nutrients are depleted rapidly. Almost no other vegetation is found under eucalyptus trees and less birds are found nesting in eucalyptus plots.
Getting rid of eucalyptus trees is also difficult because remaining strum can sprout a new eucalyptus tree, if not uprooted fully. In this case the question arises – “what types of trees are environment friendly?” Planting trees should be conducted by first understanding the environmental circumstances and an individual should plant trees that are fruit-bearing and that produce quality timber simultaneously.
Despite all the negative impacts of eucalyptus, people are still planting it for financial gain. As our ground water level is decreasing, we need to have a strong and adequate plan, fund and policy which will address issues like this type of exotic plantation. Without effective policy implementation this type of initiative will go into vain. We need to remember one thing that is- “Less vegetation leads Human Settlements into more Vulnerability” (Chowdhury,2020).