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Title: Stable isotopes contain substantial additive information about terrestrial carbon and water cycling

Stable isotope ratios of H (δ2H), O (δ18O), and C (δ13C) are linked to key biogeochemical processes of the water and carbon cycles; however, the degree to which isotope-associated processes are reflected in macroscale ecosystem flux observations remains unquantified. Here through formal information assessment, new measurements ofδ13C of net ecosystem exchange (NEE) as well asδ2H andδ18O of latent heat (LH) fluxes across the United States National Ecological Observation Network (NEON) are used to determine conditions under which isotope measurements are informative of environmental exchanges. We find all three isotopic datasets individually contain comparable amounts of information aboutNEEandLHfluxes as wind speed observations. Such information from isotope measurements, however, is largely unique. Generally,δ13C provides more information aboutLHas aridity increases or mean annual precipitation decreases.δ2H provides more information aboutLHas temperatures or mean annual precipitation decreases, and also provides more information aboutNEEas temperatures decrease. Overall, we show that the stable isotope datasets collected by NEON contribute non-trivial amounts of new information about bulk environmental fluxes useful for interpreting biogeochemical and ecohydrological processes at landscape scales. However, the utility of this new information varies with environmental conditions at continental scales. This study provides an approach for quantifying the value adding non-traditional sensing approaches to environmental monitoring sites and the patterns identified here are expected to aid in modeling and data interpretation efforts focused on constraining carbon and water cycles’ mechanisms.

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Publisher / Repository:
IOP Publishing
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Journal Name:
Environmental Research Letters
Page Range / eLocation ID:
Article No. 094065
Medium: X
Sponsoring Org:
National Science Foundation
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