Antarctica’s Native Flowering Plants Take Opposite Paths Under Warming

When researchers set up open-top warming chambers on King George Island in December 2012, they revealed that Antarctica’s only two native flowering species are coping with maritime climate shifts through starkly opposite physiological strategies, according to a study published on October 26, 2026, in the scientific journal Physiologia Plantarum.

Antarctic Hair Grass Drops Water Flow Under Experimental Warming Chambers

Inside the hexagonal open-top chambers, Antarctic hair grass reduced its leaf hydraulic conductance and photosynthetic rate over the seven-year experiment. Patricia Sáez of the Universidad de La Frontera and Universidad de Concepción explained that the grass prioritizes a conservative water-use strategy centered on stability and hydraulic safety.

Antarctic Pearlwort Increases Photosynthesis and Vascular Transport

Antarctic pearlwort displayed the exact opposite reaction to the same experimental warming conditions. The pearlwort increased its hydraulic conductivity, photosynthetic capacity, cell-wall elasticity, and water and carbon dioxide transport by about 44 percent. Lohengrin Cavieres noted that the pearlwort develops a compact cushion growth form, which helps conserve heat and buffers the plant against rapid daily temperature fluctuations.

Freeze-Thaw Cycles Drive Divergent Plant Strategies Across King George Island

The divergent responses stem from how each species handles environmental extremes rather than simple mean temperature increases. During the 2018–2019 summer, the chambers behaved differently: daily highs inside were only about 1°C warmer than in nearby open plots, but daily lows were about 2°C colder. Plants in the chambers spent 309 hours below freezing that season, compared with 32 hours outside. Plant ecophysiologist Tom Buckley and polar terrestrial ecologist Peter Convey pointed out that maritime Antarctic warming brings frequent freeze-thaw cycles across 0°C. While the loosely structured hair grass remains fully exposed to these swings, the pearlwort cushion growth form dampens day-to-day impacts.

Microbial Communities and Long-Term Chamber Data Shape Future Research

Sáez and her research team are currently studying plants that have spent 16 years in the chambers, expanding their investigation to examine surrounding microorganisms that may also be affected by regional warming. While independent researchers praised the level of anatomical detail captured near Poland’s Henryk Arctowski Antarctic Station, questions remain regarding how these plant strategies will alter species dominance and resource competition in the coming decades.