A team of Chilean and Spanish researchers has published in the scientific journal Physiologia Plantarum the results of one of the longest-running in situ warming experiments conducted in maritime Antarctica: seven years of exposure to passive warming chambers (Open Top Chambers, OTCs) applied to the Antarctic continent’s only two native vascular plant species, Deschampsia antarctica (Antarctic hairgrass) and Colobanthus quitensis (Antarctic pearlwort).
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. Both institutions are funded by Chile’s National Agency for Research and Development (ANID). The study shows that these species developed contrasting physiological responses to the same warming scenario.
Two Strategies, One Shared Challenge
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, supported by changes 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,” explains Dr. Sáez.
According to Dr. 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.”
A One-of-a-Kind Experiment
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 a sustained warming regime, making 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.
Dr. 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 an increasingly 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,” adds Dr. Cavieres.
The research involved collaboration among researchers from the Institute of Ecology and Biodiversity (IEB), Universidad de La Frontera, Universidad de Concepción, Universidad Autónoma de Chile, and Spanish research centers (CITA-Aragón, EEAD-CSIC, and the University of the Balearic Islands).
Physiologia Plantarum
Experimental study
Not applicable
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