In 2022, the environment ministry granted the proponents of the Great Nicobar development project permission to deforest 130.75 sq km of forest land to build an international transhipment port, a township, a power station and an airport on the island. The government claimed that only 50% of this forest area, around 6,500 hectares, would actually be deforested, and that around 8.5 lakh trees would be cut.
However, according to calculations by a rainforest ecologist with three decades of experience, these deforestation figures are gross underestimates. The ecologist argued that there is a mismatch between government estimates of the density of trees in the Nicobar rainforest, and the estimates of reputed scientists and research institutes of the density of forests in the region.
The ecologist noted that if the government claims that 8.5 lakh trees are to be cut across 6,500 hectares, it is in effect claiming that there are 130 trees per hectare of the forest. This value for the density of the forest seems questionable, the ecologist argued. “This is the kind of density you would see in places like Gujarat or Rajasthan, where there are dry thorn forests, scattered trees with grass and shrubs,” said the ecologist who requested anonymity to ensure that the organisation they worked for did not face any backlash. “Whereas the Nicobars are almost a primaeval forest.”
In contrast to the government’s estimation, scientific research on the Andaman and Nicobar islands by scholars has found that the density of the trees in the forests, which include mangroves, littoral forests and dense tropical rainforests, ranges between 500 trees and 900 trees per hectare. By this estimate, clearing 6,500 hectares of forest would mean cutting between 32 lakh trees and 58 lakh trees. If all 13,000 hectares of forests for which the government has granted clearance are cut, the number of trees that will be cut could be as high as 1 crore.
How the government estimated tree density
While the environment impact assessment of the project itself does not mention the number of trees that are to be cut, the figure can be found in a set of annexures uploaded on the environment ministry’s website. In these, the ministry has issued responses to comments and concerns it received on the draft environmental impact report of the project.
Against one such concern, which states “no details of the trees to be felled had been given”, the ministry responded, “Number of trees to be felled is about 8,52,245.” This estimate was reinforced by a response from the environment and forests minister to a Rajya Sabha question in July. The minister stated that trees would be felled only in 50% of the 13,000 hectares of forest that had been granted clearance. The number of trees likely to be cut was “less than 9.64 lakhs”, according to this response.
These figures, and the concomitant figures of density of between 130 trees and 150 trees per hectare “seems completely odd”, said Akshay Surendra, an ecologist who has worked in the Andamans and was not involved in the first ecologist’s calculations. He added “it depends on what metric the government may have used” to arrive at the figures.
The first ecologist explained that usually, when biologists enumerate trees, a standard practice is to include only those trees whose girth – the circumference of the trunk – is at least 30 cm.
The government could have arrived at a lower estimate of tree density simply because it counted only trees with a larger girth, Surendra argued. “If they only looked at bigger trees, then they are artificially changing the number to say there are fewer trees that would be cut,” he said.
Information about this should be public. In the same document where it mentions the number of trees that will be cut, the ministry referred to an “annexure X” that contained details of the calculations it carried out. However, the publicly available version of this annexure, as well as a few others, is blurred and entirely illegible.
Scroll sent queries to the environment ministry and the Andaman and Nicobar Islands Integrated Development Corporation, which is the project proponent, about these calculations of the number of trees that will be cut. This story will be updated if they respond.
Estimates from independent studies
Several studies carried out in the Andaman and Nicobar Islands over the years have found that the islands have a much higher tree density than the government’s estimates – most of these calculations indicated an overall density of between 500 trees and 700 trees per hectare
The highest estimate found in these studies was in a 2003 paper by Indian primatologists Govindhaswamy Umapathy and Mewa Singh. The scientists estimated that Great Nicobar has a density of 996.9 trees per hectare. If this density is used as the basis to calculate the number of trees lost across 6,500 hectares, the total figure would be around 65 lakh trees. This paper considered trees that had a girth of 15 cm or more.
Three other studies conducted on the Andaman islands in 2008 and 2009 also indicated a higher range than the government’s estimate. These studies, by scientists from several institutes and bodies including the Botanical Survey of India, Pondicherry University, Indian Council of Forestry Research and Education, and National Remote Sensing Centre took into consideration trees of 30 cm girth or more.
Surendra noted that while the forests of the Andaman islands and those of the Nicobar islands are different, “they both have a lot more trees than, say, open forests of central India, where 129 trees per hectare is possible”. In fact, he noted, “Nicobar is much wetter rainforest than Andamans, it's less seasonal”. So, he added, “If anything, Andamans are an underestimate of how many trees there are on Great Nicobar.”
One of the studies based in North Andamans, calculated the density range for different types of forests on the island – it found that its tropical rainforests had 515 trees per hectare, its tropical semi evergreen forests had 487 trees per hectare and its tropical moist deciduous forests had 522 trees per hectare.
Another of the studies examined two sites of giant evergreen forests in Middle Andaman and estimated that they had densities of 579 trees and 732 trees per hectare respectively. The third study, based in Little Andaman, calculated densities of “undisturbed” evergreen, semi-evergreen, deciduous, and littoral forests on the island, and found that they ranged between 488 to 935 trees per hectare.
In fact, the government’s estimates appear to be undermined by the project’s own impact assessment report, which includes a description from consultants who visited Great Nicobar to conduct a tree survey for the project.
The report stated that in the area they surveyed, “thick forest vegetation with impenetrable shrubs and climbers was not accessible without clearing the vegetation and making the way”. It refers to “multi-storeyed vegetation”, “dense/thick forest” which led to poor visibility, and “overgrown” trees with heavy climbers. It noted that “when one tries to look upwards to find out what tree it is, it is not just one but many”.
The first ecologist noted that this description corresponded more to a high density forest, than one that would contain 129 trees per hectare. “Those indications fit well with a tropical rainforest or tropical wet evergreen forest with tree densities that will be 4 to 8 times higher, in the range of 500 to 1,000 trees per hectare,” they said.
Accounting for other limitations
Could it be that the density of forests reduced between the time these studies were conducted and the present day? Ecologists do not think so.
Even a natural disaster as large as the 2004 tsunami, which occurred after one of these studies was conducted, could not have so drastically changed the density, they noted. “The impact was on the shoreline, and the inland forest was minimally affected, particularly so because Great Nicobar is also undulating,” Surendra said. Given the nature of the terrain, he explained, trees on higher slopes would have remained protected during the disaster. “It’s impossible that the entire 6,500 hectares of forest have been affected by the tsunami,” leading to a density as low as around 130 trees per hectare, he added.
Further, Surendra argued, “Even incorporating for time, changes in tree density are extremely miniscule. On average, especially for such large areas of forest, the density of trees can remain the same for hundreds of years.”
In fact, as part of their analysis, the first ecologist also carried out one calculation under the assumption that 20% of the area under consideration would have rivers, streams or large rocks, which could be considered as “gaps” where trees do not grow. “The 20% was just a rough estimate to arrive at an even more conservative estimate,” they said. Even with this assumption, the figure for the number of trees likely to be cut was 26 lakh, still far higher than the government’s claim of 8.5 lakh.
“A thorough, careful and, importantly, transparent survey should be carried out by professional ecologists or trained foresters,” the ecologist said. “Maps of area to be felled, plot locations, method used and results obtained must be made public.”
