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Asymmetric responses of primary productivity to altered precipitation simulated by ecosystem models across three long-term grassland sites

Wu, D.; Ciais, P.; Viovy, N.; Knapp, A. K.; Wilcox, K.; Bahn, M.; Smith, M. D.; Vicca, S.; Fatichi, S.; Zscheischler, J.; He, Y.; Li, X.; Ito, A.; Arneth, A.; Harper, A.; Ukkola, A.; Paschalis, A.; Poulter, B.; Peng, C.; Ricciuto, D.; ... mehr

Abstract:
Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation (P) may occur. Under normal range of precipitation variability, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether the current generation of ecosystem models with a coupled carbon–water system in grasslands are capable of simulating these asymmetric ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with 14 ecosystem models at three sites: Shortgrass steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that (1) the spatial slopes derived from modeled primary productivity and precipitation across sites were steeper than the temporal slopes obtained from inter-annual variations, which was consistent with empirical data; (2) the asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the mean of the model ensemble suggested a negative asymmetry across the three sites, which was contrary to empirical evidence based on filed observations; (3) the mean sensitivity of modeled productivity to rainfall suggested greater negative response with reduced precipitation than positive response to an increased precipitation under extreme conditions at the three sites; and (4) gross primary productivity (GPP), net primary productivity (NPP), aboveground NPP (ANPP) and belowground NPP (BNPP) all showed concave-down nonlinear responses to altered precipitation in all the models, but with different curvatures and mean values. ... mehr

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Verlagsausgabe §
DOI: 10.5445/IR/1000083775
Veröffentlicht am 25.06.2018
Originalveröffentlichung
DOI: 10.5194/bg-15-3421-2018
Scopus
Zitationen: 21
Web of Science
Zitationen: 19
Dimensions
Zitationen: 23
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Geographie und Geoökologie (IFGG)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2018
Sprache Englisch
Identifikator ISSN: 1726-4170, 1726-4189
urn:nbn:de:swb:90-837752
KITopen-ID: 1000083775
Erschienen in Biogeosciences
Verlag Copernicus Publications
Band 15
Heft 11
Seiten 3421-3437
Nachgewiesen in Dimensions
Web of Science
Scopus
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