A new field study from northwestern China reveals that climate-driven changes in temperature and moisture could significantly reshape nitrous oxide emissions from soils in arid mountain ecosystems, with important implications for future climate feedbacks.
Nitrous oxide is a powerful greenhouse gas that traps nearly 300 times more heat than carbon dioxide over a century. Although drylands cover roughly 40 percent of the Earth's land surface, their contribution to global nitrous oxide emissions has been poorly understood. The new research helps fill this gap by examining how soil emissions vary across elevation and land-use types in the Xinjiang region of China.
Researchers conducted field measurements across forests, grasslands, croplands, and barren lands along an elevation gradient spanning more than 2,500 meters in the Tianshan Mountains. By combining gas flux measurements with soil chemistry and microbial analyses, the team was able to identify both environmental and biological factors controlling emissions.
The results show that managed cropland soils produced by far the highest nitrous oxide emissions, largely due to irrigation, fertilization, and favorable soil moisture conditions. In contrast, emissions from natural ecosystems were much lower overall, but their response to elevation differed sharply between vegetation types.
Grassland soils showed a clear increase in emissions with elevation. As altitude rose, soils became cooler but also wetter, conditions that promoted microbial processes responsible for producing nitrous oxide. At the highest sites, emissions were several times greater than those observed at lower elevations.
"Elevation acts as a natural climate experiment," the study's corresponding author explained. "It allows us to see how warming and changing rainfall patterns may reshape soil greenhouse gas emissions in the future."
Forest soils behaved in the opposite way. Emissions were highest at lower elevations and declined sharply higher up the mountain. The researchers found that temperature played a stronger role than moisture in forests, with colder conditions at higher elevations limiting microbial activity that produces nitrous oxide.
The study also showed that different microbial communities drive these contrasting patterns. In grasslands, microorganisms involved in denitrification became more active in wetter soils, boosting emissions. In forests, the abundance of key microbial groups declined with cooler temperatures, helping suppress nitrous oxide release.
Together, the findings suggest that climate change could shift the balance of greenhouse gas emissions across ecosystems in arid mountain regions. Warmer and wetter conditions may transform some natural grasslands into more significant sources of nitrous oxide, while land management practices will continue to dominate emissions from agricultural soils.
"Our work highlights that both climate sensitivity and human management must be considered together when predicting greenhouse gas emissions from dryland regions," the author said. "Ignoring either factor could lead to serious underestimation of future climate feedbacks."
Because arid and semi-arid regions occupy such a large portion of the planet, improved understanding of their soil emissions is essential for refining global greenhouse gas budgets and climate projections.
The researchers conclude that long-term monitoring across environmental gradients will be critical for predicting how dryland ecosystems respond to ongoing climate change, and for developing land-use strategies that minimize greenhouse gas emissions while sustaining productivity.
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Journal Reference: Wu Z, Wu L, Chen D, Niu Z, Yang T, et al. 2026. Soil N2O emission along an elevation gradient in the arid zone of Xinjiang, Northwestern China. Nitrogen Cycling 2: e010 doi: 10.48130/nc-0025-0022
https://www.maxapress.com/article/doi/10.48130/nc-0025-0022
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