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dc.contributor.authorRoby, Matthew C.
dc.contributor.authorScott, Russell L.
dc.contributor.authorBarron-Gafford, Greg A.
dc.contributor.authorHamerlynck, Erik P.
dc.contributor.authorMoore, David J. P.
dc.date.accessioned2020-01-24T20:03:58Z
dc.date.available2020-01-24T20:03:58Z
dc.date.issued2019-01-08
dc.identifier.citationRoby, M.C.; Scott, R.L.; Barron-Gafford, G.A.; Hamerlynck, E.P.; Moore, D.J.P. Environmental and Vegetative Controls on Soil CO2 Efflux in Three Semiarid Ecosystems. Soil Syst. 2019, 3, 6.en_US
dc.identifier.issn2571-8789
dc.identifier.doi10.3390/soilsystems3010006
dc.identifier.urihttp://hdl.handle.net/10150/636707
dc.description.abstractSoil CO2 efflux (F-soil) is a major component of the ecosystem carbon balance. Globally expansive semiarid ecosystems have been shown to influence the trend and interannual variability of the terrestrial carbon sink. Modeling F-soil in water-limited ecosystems remains relatively difficult due to high spatial and temporal variability associated with dynamics in moisture availability and biological activity. Measurements of the processes underlying variability in F-soil can help evaluate F-soil models for water-limited ecosystems. Here we combine automated soil chamber and flux tower data with models to investigate how soil temperature (T-s), soil moisture (theta), and gross ecosystem photosynthesis (GEP) control F-soil in semiarid ecosystems with similar climates and different vegetation types. Across grassland, shrubland, and savanna sites, theta regulated the relationship between F-soil and T-s, and GEP influenced F-soil magnitude. Thus, the combination of T-s, theta, and GEP controlled rates and patterns of F-soil. In a root exclusion experiment at the grassland, we found that growing season autotrophic respiration accounted for 45% of F-soil. Our modeling results indicate that a combination of T-s, theta, and GEP terms is required to model spatial and temporal dynamics in F-soil, particularly in deeper-rooted shrublands and savannas where coupling between GEP and shallow theta is weaker than in grasslands. Together, these results highlight that including theta and GEP in F-soil models can help reduce uncertainty in semiarid ecosystem carbon dynamics.en_US
dc.description.sponsorshipUSDA-ARSUnited States Department of Agriculture (USDA); U.S. Department of Energy Berkeley National Labsen_US
dc.language.isoenen_US
dc.publisherMDPIen_US
dc.rightsCopyright © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).en_US
dc.subjectsoil respirationen_US
dc.subjectdrylandsen_US
dc.subjectwater availabilityen_US
dc.subjectspatial variationen_US
dc.subjecttemporal dynamicsen_US
dc.subjectpulsesen_US
dc.subjectphotosynthesisen_US
dc.subjectecosystem respirationen_US
dc.titleEnvironmental and Vegetative Controls on Soil CO2 Efflux in Three Semiarid Ecosystemsen_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Sch Nat Resources & Environm, Tucson, AZ 85721 USAen_US
dc.contributor.departmentUniv Arizona, Sch Geog & Dev, Tucson, AZ 85721 USAen_US
dc.contributor.departmentUniv Arizona, Coll Sci, Biosphere 2, Tucson, AZ 85721 USAen_US
dc.identifier.journalSOIL SYSTEMSen_US
dc.description.noteOpen access journalen_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal published versionen_US
dc.source.volume3
dc.source.issue1
dc.source.beginpage6
refterms.dateFOA2020-01-24T20:03:58Z


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