Spatial variability of nitrous oxide emissions from croplands and unmanaged natural ecosystems across a large environmental gradient.

Atmospheric nitrous oxide (NO) is a potent greenhouse gas, with long atmospheric residence time and a global warming potential 273 times higher than CO. NO emissions are mainly produced from soils and are influenced by biotic and abiotic factors that can be substantially altered by anthropogenic activities, such as land uses, especially when unmanaged natural ecosystems are replaced by croplands or other uses. In this study, we evaluated the spatial variability of NO emissions from croplands (maize, soybean, wheat, and sugar cane crops), paired with the natural grasslands or forests that they replaced across a wide environmental gradient in Argentina, and identified the key drivers governing the spatial variability of NO emissions using structural equation modeling.

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

Nitrous oxide (NO), a main greenhouse gas that contributes to ozone layer depletion, is released from soils. Even when it has been argued that agriculture is the main cause of its increase in the atmosphere, natural ecosystems are also an important source of NO. However, the impacts of human activities on NO emissions through biodiversity loss or primary productivity changes in natural ecosystems have rarely been assessed.