Nitrous oxide emissions decrease with plant diversity but increase with grassland primary productivity.

Area of Science:

• Environmental Science
• Ecology
• Soil Science

Background:

• Nitrous oxide (N₂O) is a significant greenhouse gas contributing to ozone depletion, with both agricultural and natural ecosystems releasing it.
• The influence of human-induced biodiversity loss and productivity changes on N₂O emissions from natural ecosystems remains understudied.

Purpose of the Study:

• To investigate the impact of vegetation attributes (plant diversity, primary productivity) and environmental factors on N₂O emission rates in natural grasslands.
• To differentiate spatial and temporal drivers of N₂O emissions using independent modeling approaches.

Main Methods:

• Monthly measurements of N₂O emissions over one year across 12 sites in the Rio de la Plata grasslands, Argentina.
• Analysis of relationships between N₂O emissions and climate, soil, and vegetation attributes.
• Development of separate spatial and temporal models to identify independent controlling factors.

Main Results:

• Spatially, increased plant species richness correlated with decreased N₂O emissions and soil [FORMULA].
• Higher primary productivity was associated with increased N₂O emissions across space.
• Temporally, monthly precipitation and temperature were the primary drivers of N₂O emissions, showing positive correlations.

Conclusions:

• Biological drivers, alongside climate and soil variables, significantly control N₂O emissions at broad spatial scales.
• Conservation of natural grassland biodiversity can potentially mitigate regional greenhouse gas emissions and preserve ecosystem services.