{
  "id": 10521997,
  "title": "Coast redwoods slow their 'breathing' and 'eating' when temperatures spike",
  "url": "https://urgent.news/2026/09/28/coast-redwoods-slow-their-breathing-and-eating-when-temperatures-spike",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-28T20:00:14.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-09-coast-redwoods-temperatures-spike.html"
  },
  "original_language": "en",
  "account": "Coastal redwood trees are accustomed to the cool, coastal climate of northern California, with temperatures averaging around 15°C (59°F). However, as average temperatures rise and heatwaves push temperatures above 38°C (100°F), these majestic trees are exhibiting a worrying response. According to a new study from the University of California, Davis, redwoods slow their breathing and eating when exposed to high temperatures.\n\nThe study, published in JGR Biogeosciences, is the first to investigate the effects of heat on coast redwood photosynthesis. Lead author Lily Klinek, a Ph.D. candidate, explained that prolonged heat stress causes the trees' leaves to become significantly warmer than the surrounding air, signaling a decline in their cooling capacity. This inability to cool down effectively leads to the closure of stomata, the tiny pores that allow the trees to breathe in carbon dioxide.\n\nFurther lab experiments confirmed that even with stomata open, photosynthesis was significantly reduced at temperatures up to 43°C (110°F). The researchers concluded that heat stress can impair the trees' carbon uptake independently of water stress. While trees can regulate their temperature through evapotranspiration, generating moisture to cool themselves, the study found that even well-watered redwoods experienced a decrease in photosynthesis when exposed to high temperatures.\n\nThe findings highlight the vulnerability of redwood forests, especially in their more vulnerable southern and eastern regions of California. Understanding the upper temperature thresholds for redwood photosynthesis and mortality is crucial for assessing which parts of their range may be at risk and identifying potential interventions to support the health of these iconic ecosystems.",
  "summary": "California's iconic coast redwoods are used to growing in cool, coastal areas where the average temperature is around 59 degrees F (15 degrees Celsius). But as average yearly temperatures rise and heat waves push temperatures above 100 degrees F (38 degrees Celsius), the trees are responding by slowing the very process that nourishes them, according to a study from the University of California,…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}