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: A team of Chilean and Spanish researchers has published the results of one of the longest-running in-situ warming experiments in maritime Antarctica in the journal Physiologia Plantarum. The experiment exposed the Antarctic continent's only two native vascular plant species, Deschampsia antarctica (Antarctic hairgrass) and Colobanthus quitensis (Antarctic pearlwort), to passive warming chambers (Open Top Chambers, OTCs) for seven years.
The study involved researchers from the Institute of Ecology and Biodiversity (IEB), Dr. Patricia Sáez (Universidad de La Frontera, UFRO) and Dr. Lohengrin Cavieres (Universidad de Concepción, UDEC), as well as researchers from the Anillo ATE253400 project.
The study shows that the species developed contrasting physiological responses to the same warming scenario. After seven years under passive warming conditions, D. antarctica reduced both its leaf hydraulic conductivity and photosynthetic rate, which the authors interpret as a conservative water-use strategy. C. quitensis, by contrast, showed the opposite response: It increased its hydraulic conductivity, photosynthetic capacity, cell-wall elasticity, and water and CO₂ transport.
Those changes were supported by shifts in its vascular anatomy and its cushion growth form, which helps conserve heat. "These results show that coordination between hydraulic function and photosynthesis is key to the survival of Antarctic plants, but that each species has addressed this challenge differently: one prioritizing stability and hydraulic safety, the other plasticity and rapid acclimation," Sáez explains. According to Cavieres, these findings help explain why both species have managed to coexist and expand in Antarctica over recent decades despite regional warming: "What is interesting is that there is no single 'correct' way to respond to climate change.
These two plants represent two extremes along the same adaptive continuum, and this diversity of strategies is probably part of what explains their shared success in one of the most extreme environments on the planet." The fieldwork was conducted on King George Island, near the Polish Antarctic Station Henryk Arctowski, in experimental plots established in 2012. It is the first field study to jointly assess leaf hydraulic traits, xylem anatomy and photosynthetic performance in both Antarctic species under sustained warming. That made it possible to capture ecologically relevant aspects of climate change, such as increases in freeze-thaw events, rather than focusing solely on rising mean temperatures.
Sáez adds, "What we found is that coordination between water transport and photosynthesis is essential for these plants to survive in Antarctica, but each species addressed this challenge differently under warming: Deschampsia prioritized stability, while Colobanthus prioritized plasticity. This contrast provides valuable clues about how Antarctic vegetation may respond to a changing climate." "These two plants have coexisted in Antarctica for a long time, and this study shows us one possible reason why: they do not compete for resources in the same way because they respond to warming differently. Understanding this complementarity is key to anticipating how Antarctic vegetation will change over the coming decades," Cavieres adds.
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