What happened
- On October 23, 2026, Communications Earth & Environment published a global meta-analysis of how nitrogen deposition affects the stability of grassland productivity.
- The work, from East China Normal University in Shanghai, gathered 542 multi-year observations from 111 studies.
- Nitrogen addition significantly reduced the stability of both above-ground and below-ground primary productivity, and did so in a synchronised way.
- The negative effects grew stronger with longer treatments and higher nitrogen doses.
Why it matters
- Productivity stability, the ratio of its average to its variation over time, supports services such as forage and carbon storage.
- Little was known about whether changes in the above-ground part of plants repeat in the roots. The study shows both respond together.
- The drop in stability was associated with the loss of plant species richness that nitrogen causes.
The number
542 observations. Multi-year measurements, drawn from 111 studies, gathered by the meta-analysis.
Context
The authors explain the coupled response by two effects: a trade-off in how plants split growth between leaves and roots, and a synchronised rise in the variability of both. The authors call for considering above- and below-ground interactions in ecosystem management under global change. Species diversity as a backbone of ecosystems also appears in the Caribbean origin of barn owls.
What’s next
- The results point to measuring roots, not only above-ground biomass, in nitrogen experiments.
- The authors propose including this coupled response in grassland management strategies.
Bottom line
More nitrogen makes grass grow but makes it less predictable above and below the ground. Climate had other recent readings, such as the Baffin ice cap, Antarctic sea ice in 2026 and the improvement in ECMWF forecasts weeks ahead.
Sources
- Communications Earth & Environment — Coupled responses of aboveground and belowground net primary productivity stability to nitrogen deposition in grasslands (October 23, 2026)
- Cover image: Sergio Tittarini, CC BY 2.0, via Wikimedia Commons
Edited by Rodrigo Cornejo. How we select and verify: who writes these notes.
