High winds during El Niño could be deadly for England’s stressed trees, say experts

High winds linked to the powerful El Niño event are expected to exacerbate the already dire condition of England’s trees, which have been severely stressed by a record-breaking summer of extreme heat and drought, according to experts. The Met Office has indicated that the upcoming El Niño, projected to be the strongest in over a century, will bring increased rainfall and stronger storms to the UK this autumn. This combination of factors threatens to trigger widespread tree mortality, particularly among species such as the silver birch, common beech, and oak, which are becoming increasingly vulnerable due to prolonged exposure to harsh climatic conditions. The summer of 2026 has been marked by relentless heat, with temperatures reaching historic levels. Kevin Martin, head of tree collections at Kew Gardens, noted that the growing season was unusually stressful, with the spring heatwave pushing temperatures to 35°C, making it the hottest May on record. This extreme warmth disrupted normal tree growth patterns, resulting in weaker, more brittle structures. Martin emphasized that the cumulative effect of this stress, combined with the anticipated strong winds of El Niño, could lead to catastrophic consequences for England’s forests. “We may lose species like the silver birch, the common beech and oak from landscapes where we’re used to seeing them,” he warned. The impact of the recent heat and drought has been particularly severe on older trees, with many ancient oaks showing signs of decline. Martin pointed out that the 2022 heatwave resulted in the loss of over 400 trees at Kew Gardens alone, and he fears the situation could deteriorate further this year. “From what I can see from the landscape here at Kew, we’re going to see a lot more mortality than what we saw in 2022 because a lot of trees that just got through 2022 are not going to make it through this year,” he stated. The full extent of the damage, however, is unlikely to be fully understood until the following two to three years. Experts warn that the ongoing sequence of extreme weather events poses a unique challenge. Simon Richmond, a technical officer at the Arboricultural Association, highlighted that while individual instances of extreme weather can often be managed by trees, the persistent nature of these conditions presents a greater risk. “The danger that we face now is the likelihood with climate change of this being a prolonged pattern of weather,” he said. Marcus Lindner, a principal scientist at the European Forest Institute, echoed similar concerns, noting that repeated droughts could push many species beyond their adaptive limits. “Species that are normally drought-tolerant are adapted to a certain level of drought stress, but if we have continuous and repeated drought these trees will at some point not be comfortable with that any more,” he explained. Gardeners and arborists are being urged to take proactive measures to safeguard trees against the impending stormy conditions. Ross Cameron, a professor at the University of Sheffield, described the current state of trees as highly vulnerable, citing examples of branches collapsing due to internal water transport issues caused by prolonged drought. He recommended regular inspections for larger trees and pruning of dead material from smaller ones to reduce the risk of collapse during strong winds. Alistair Griffiths, director of science at the Royal Horticultural Society, cautioned against replacing all garden flora with drought-resistant Mediterranean species, emphasizing the need for resilience against both dry and wet conditions. As the UK prepares for the arrival of El Niño, the focus is shifting towards understanding the long-term implications for England’s ecosystems. The loss of trees not only affects biodiversity and carbon storage but also undermines critical functions such as flood control. Experts at Kew Gardens are working to develop strategies for adapting landscapes to future climatic realities, including introducing more resilient species and promoting diverse planting practices. With the current El Niño expected to intensify existing climate trends, the urgency for action has never been clearer.