This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Recurring and prolonged periods of drought are worsening worldwide, triggering a dangerous chain reaction for trees, according to a forest health expert at North Carolina State University. Trees rely on soil moisture to transport nutrients, cool their leaves and create food through photosynthesis — all vital processes for survival.
Drought removes that moisture. "As soils dry out, trees can no longer take up water fast enough to meet the demands of the canopy," said Kelly Oten, an assistant professor and Extension specialist in the Department of Forestry and Environmental Resources at NC State. This shortage of water, Oten added, can "severely compromise trees," weakening them and making them more susceptible to structural collapse, weather damage, pest infestations and diseases.
In 2023, for example, southern pine beetles killed an estimated 12.5 million drought-stressed pine trees across nearly 80,000 acres (125 square miles) in Mississippi. Such widespread losses will likely become more common as climate change drives more frequent, intense and prolonged droughts. Future climate models project that the frequency, duration and severity of droughts will increase globally, with up to 62% of land area facing severe conditions under high-emission scenarios.
In the following FAQ, Oten addresses common questions about the effects of drought on tree health, from identifying the warning signs of stress to implementing recovery strategies. Drought-stressed trees shut down vital functions to conserve moisture, triggering visible symptoms. One of the earliest warning signs is leaf wilting.
"Just like an indoor plant that wilts when it goes unwatered, leaves often begin to droop or curl because the tree can't move enough water from the roots to the canopy," Oten said. Trees may also develop leaf scorch — a condition where the edges of their leaves turn brown and crispy — or begin dropping leaves prematurely. "If you step back and look at the entire tree, the canopy may appear thinner than it did in previous years or the leaves may be smaller than normal," Oten said.
During periods of prolonged drought, trees sometimes experience twig dieback, when the tips of their branches dry out and die. Twig dieback is a sign that a stressed tree is entering "survival mode," according to Oten. By sacrificing its outer twigs, it can prioritize survival over growth until conditions improve.
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