Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily—and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have… More

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Global-scale studies suggest that dryland ecosystems dominate an increasing trend in the magnitude and interannual variability of the land CO2 sink. However, such analyses are poorly constrained by measured CO2 exchange in drylands. Here we address this observation gap with eddy covariance data from 25 sites in the water-limited Southwest region of North America with… More

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Estimates of net ecosystem exchange (NEE) of CO2 have been measured on a variety of ecosystems world wide including grasslands, savannahs, boreal, pine, deciduous, Mediterranean and tropical rain forests as well as arctic tundra. While there have been numerous comparisons between net primary productivity of arid and semiarid grasslands and shrublands, notably lacking are estimates… More

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Arid environments represent 30% of the global terrestrial surface, but are largely under-represented in studies of ecosystem carbon flux. Less than 2% of all FLUXNET eddy covariance sites exist in a hot desert climate. Long-term datasets of these regions are vital for capturing the seasonal and interannual variability that occur due to episodic precipitation events… More

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