More than 25,000 mature teak trees have died across 16,800 hectares in Madhya Pradesh's West Betul forest division.
Forest officials suspect prolonged drought and heat stress caused hydraulic failure, disrupting water transport within the trees.
Investigations found no evidence of fungal or pest infections in tested samples, while larger and older trees were particularly affected.
Satellite data showed signs of vegetation and moisture stress as early as 2022–23, before widespread tree deaths became apparent.
Officials say the scale of teak mortality is unprecedented in the region over the past two decades, raising concerns about forest management and timber resources.
More than 25,000 mature teak trees have died across forests in Madhya Pradesh's Betul district over the past three years, with investigations pointing to prolonged drought, heat stress and disrupted water transport within the trees as possible causes.
A tree-by-tree GPS survey led by Pradeep Mishra, deputy conservator of forests and working plan officer in Betul, recorded the dead trees across 16,800 hectares in five ranges of the West Betul forest division.
The findings have raised concerns about the impact of changing climatic conditions on teak forests, which have significant ecological and commercial value.
Betul is one of India's major teak-producing districts, generating more than Rs 100 crore annually from timber harvesting, according to Mishra. Teak trees generally take 20-25 years to reach commercial maturity, making the loss of older trees particularly significant.
Teak is valued for its high-quality timber and plays an important economic and ecological role in India's tropical forests. It is naturally resistant to several pests and diseases because it contains compounds such as tectoquinone, lapachol and deoxylapachol, which also contribute to its durability, according to the Indian Council of Forestry Research and Education-Tropical Forest Research Institute (TFRI).
A 2010 study published in the journal Mitigation and Adaptation Strategies for Global Change projected that around 30 per cent of India's teak-growing areas could become unsuitable under changing climatic conditions.
Mishra said teak mortality had been reported since around 2023 but became increasingly noticeable in 2025 and 2026. “The problem started around 2023 and has gradually become worse. Mortality was gradual at first and only became noticeable in large numbers in 2025-26,” he told Down To Earth. Most affected trees measured 60-150 centimetres in girth and were estimated to be between 40 and 120 years old or older.
After forest staff reported dead teak trees in Gwasen, Mishra visited the affected areas in April 2026.
“What I saw was unusual. Large teak trees were standing completely dry, but there was no sign of borer, termite or fungus. When we examined a few trees, the wood was sound, not hollow or rotten,” he said.
Rather than immediately removing the dead trees, Mishra initiated a census with Joint Forest Management Committees to record their girth and GPS coordinates. The survey identified affected trees across West Betul, Sawaligarh, Chicholi, Tawadi and Mohda ranges, with some mortality also reported in the adjoining South Betul division.
The data was combined with satellite imagery, forest surveys and laboratory investigations by the State Forest Research Institute in Jabalpur.
“As far as we know, no such scale of teak mortality has been reported in this region in the last twenty years,” Mishra said.
The findings will inform the next 10-year forest Working Plan, which determines timber harvesting, forest protection and regeneration priorities.
“The new plan must reflect what is actually happening in the forest, not what was there ten years ago,” he added.
Investigators identified three notable patterns: dead trees were scattered among healthy trees rather than concentrated in single patches; larger and older trees were more severely affected; and mortality was generally higher in drier locations.
In South Betul, an investigation by the TFRI found the highest mortality among trees measuring 90-119 cm in girth, a commercially valuable size.
The institute’s February 2025 investigation found no evidence of fungal or other pathogenic infection in the samples tested, including the fungus Phomopsis tectonae, which is associated with teak dieback.
However, it suggested that soil conditions like waterlogging could be contributing to the deaths.
The report identified possible waterlogging during the June-September monsoon, which could deprive roots of oxygen, followed by dry conditions between April and June that could damage fine feeder roots.
Mishra believes prolonged drought and heat stress have caused hydraulic failure, a process in which a tree's internal water transport system breaks down.
Water normally travels from roots to leaves through specialised tissues called xylem. During severe drought, the tension within this system can cause air bubbles to form, blocking water movement.
If the damage becomes extensive, trees may be unable to restore their water supply even after rainfall returns.
“When the soil stays dry and temperatures stay high for long, air bubbles form in these tubes and block water flow,” Mishra explained.
A 2017 study published in the journal Scientific Reports identified a thermal tolerance threshold of around 45.5 degrees Celsius (°C) for teak.
Mishra also cited a 2015 study published in journal Nature, based on a 13-year drought experiment in the Amazon, which found that hydraulic failure, rather than carbon starvation, was responsible for tree mortality, with larger trees particularly vulnerable.
Betul is considered highly drought-prone, and studies have documented declining monsoon rainfall in Madhya Pradesh between 1951 and 2010.
During the 2026 monsoon, Betul received approximately 69 per cent of its normal rainfall, according to Mishra.
The findings suggest that prolonged moisture stress, potentially combined with seasonal waterlogging, may be weakening mature teak trees.
However, the TFRI's investigation in South Betul cautioned that the dieback observed there was restricted to a few areas and did not constitute an alarming situation across the division.
It found that trees growing near those that had died were generally healthy or showed limited dieback, affecting less than 5 per cent.
This distinction is important because the South Betul investigation and the larger West Betul survey cover different forest areas and do not necessarily indicate identical levels of damage.
The deaths could have significant implications for Betul's timber resources and long-term forest management.
Mishra said the loss of mature trees would affect estimates of standing timber and sustainable harvesting levels used in the division’s 10-year Working Plan.
He also called for the timely removal of dead standing teak to prevent further deterioration of timber quality and reduce fire risks.
“Dead standing teak loses timber value over time, so timely harvesting will help protect the timber value and the state's revenue. Removal also reduces fire risk,” he said.