S>omething strange happened underground during the Amazon’s worst drought in living memory.

Soil that normally acts like a sponge, quietly pulling a plant-made gas called isoprene out of the air, mostly just stopped.

New research shows the ground’s capacity to absorb this gas fell to roughly a quarter of normal levels once drought and heat pushed conditions to extremes.

The shift has consequences that extend well beyond the rainforest floor.

The work was led by researchers at the Max Planck Institute for Chemistry in Mainz. The team spent multiple seasons measuring isoprene moving into rainforest soil.

The study included the record-breaking 2023 dry season, when a powerful El Niño drove river levels to historic lows and left vegetation across the region visibly stressed.