--- title: "Redwoods Found Vulnerable to Heat Stress Due to Leaf Anatomy" url: https://newscentral.site/redwoods-found-vulnerable-to-heat-stress-due-to-leaf-anatomy/ language: en publisher: "News Central Site" section: "Technology" published: 2026-10-11T09:00:00.000Z updated: 2026-10-11T09:47:50.537Z id: 22f8ff0e-d83c-4ecd-a0d6-e52b05605511 source: "Wired https://www.wired.com/story/californias-tallest-and-most-iconic-trees-are-getting-heat-stroke/" attribution: "Link to https://newscentral.site/redwoods-found-vulnerable-to-heat-stress-due-to-leaf-anatomy/ and name News Central Site when you quote or summarize this story." --- # Redwoods Found Vulnerable to Heat Stress Due to Leaf Anatomy Researchers at the University of California, Davis have discovered that California's iconic redwood forests are vulnerable to heat stress due to the unique anatomy of their leaves. California's majestic redwood forests have long been a source of awe and wonder for visitors from around the world. These towering trees are not just natural wonders but also provide a unique ecosystem that supports an array of plant and animal life. One of the most fascinating aspects of these elevated ecosystems is the variety of creatures that call them home, including the wandering salamander, which spends its entire life cycle on top of a single tree, and the marbled murrelet, a seabird whose nesting habits were only discovered in 1974 by chance when a tree-trimmer stumbled upon a nest 150 feet above the ground. Redwoods have been thriving for millennia, providing stability to their ecosystem and even surviving devastating wildfires that destroy other tree species. They are also a significant source of inspiration for humans and generate millions of dollars for California's tourist economy each year. But despite their resilience, these trees are not immune to the effects of rising temperatures, and researchers at the University of California, Davis have discovered a surprising weakness in their ability to cope with heat stress. The resilience of California's iconic trees has been put to the test as rising temperatures take a toll on their ability to cope with heat stress. To grasp what's happening, it's essential to understand tree anatomy, particularly the role of leaves in regulating water and carbon dioxide exchange. Leaves have tiny pores called stomata that allow them to breathe in carbon dioxide for photosynthesis while releasing excess water through transpiration. When these stomata are open, trees absorb carbon dioxide and carry out photosynthesis, but they also lose water. Conversely, when they're closed, trees conserve water by slowing down photosynthesis due to reduced carbon dioxide intake. This delicate balance is crucial for a tree's survival. According to Lily Klinek, a PhD student at UC Davis who led the study on this phenomenon, leaves are like dark objects that heat up quickly in direct sunlight. They absorb light and warm up faster than the surrounding air, causing them to overheat. As a result, trees try to regulate their temperature by opening their stomata to release excess water through transpiration, a process similar to human sweating. As leaves try to cool themselves down during heat waves, they have a limited capacity to do so. Specialized instruments were used by researchers to measure photosynthesis in individual leaves of coast redwoods in Mendocino County. This allowed them to determine the point at which these trees can no longer cool themselves efficiently. During extreme heat, coast redwoods are unable to regulate their temperature quickly enough and as a result, they keep their stomata closed. This decision to conserve water comes at a cost: the tree is unable to take in more carbon, which means it's not building up energy stores that would allow it to continue growing. While this may seem like a minor issue of tree physiology, its consequences could be far-reaching for these forests. The vast majority of redwood forests in California and the Pacific Northwest are actually relatively new, having been planted over the last couple of centuries. This means that these trees are still growing rapidly, like adolescents, and require a constant supply of carbon dioxide to reach their full height. As it turns out, redwoods are incredibly effective at storing carbon. Their massive size and long lifespan allow them to absorb and store more carbon dioxide per acre than any other type of forest in the world. This has a significant impact on the climate system, as it reduces the amount of greenhouse gases released into the atmosphere. The consequences of this heat stress could be severe for these forests. According to Anthony Ambrose, a plant physiological ecologist, if the trees are unable to sequester carbon dioxide effectively, they may not grow as big as they once did. This would have a ripple effect throughout the ecosystem, potentially leading to reduced habitat and resources for the creatures that depend on them. One of the key factors contributing to the decline of these trees is their reliance on fog. Coast redwoods in Northern California and the Pacific Northwest have developed a complex relationship with the local fogs, which provide them with essential hydration and protection. However, if the heat stress becomes too severe, it's possible that these trees may lose access to this vital source of moisture. The potential consequences for these forests are far-reaching, extending beyond the immediate impact on tree growth and health. As Ambrose noted, even if the trees survive, they may not be able to provide the same level of habitat and resources for other species in the future. The towering canopies of California's coast redwoods are reaching into fog layers where they can directly absorb water from the sky. This unique adaptation allows them to thrive in a cooler microclimate that is distinct from surrounding areas. However, this vital source of moisture is becoming increasingly unreliable due to warmer oceans and drier air. As a result, the trees are missing out on a crucial means of coping with rising temperatures. The heat stress is compounded by the fact that these trees are accustomed to living within a narrow temperature range of 8 to 27 degrees Celsius (46 to 80 degrees Fahrenheit). Deviations from this norm can have far-reaching consequences for the organisms that inhabit the upper reaches of the trees. The salamanders and birds that call these forests home may struggle to survive if the soil mats and ferns dry out too quickly. This would be a devastating loss, given the ecological importance of these species in maintaining the delicate balance of the forest ecosystem. Scientists studying the coast redwoods in California are cautiously optimistic that these iconic trees may be able to recover from heat stress during the cooler months of fall and winter. As temperatures return to normal, the trees may have a chance to replenish their water reserves and restore their delicate balance, at least temporarily. However, this respite is not a guarantee against future heatwaves or other extreme weather events that could further jeopardize the trees' survival. The fate of these towering trees hangs in the balance, not just for their own sake but also for the entire ecosystem they support, including species like salamanders and seabirds that call them home. --- Source: [Wired](https://www.wired.com/story/californias-tallest-and-most-iconic-trees-are-getting-heat-stroke/) Published by News Central Site: https://newscentral.site/redwoods-found-vulnerable-to-heat-stress-due-to-leaf-anatomy/