title: Reconciling inconsistencies in precipitation-productivity relationships: implications for climate change.
abstract: Contents 41 I. 41 II. 42 III. 43 IV. 44 V. 45 Acknowledgements 46 References 46 SUMMARY: Precipitation (PPT) is a primary climatic determinant of plant growth and aboveground net primary production (ANPP) over much of the globe. Thus, PPT-ANPP relationships are important both ecologically and to land-atmosphere models that couple terrestrial vegetation to the global carbon cycle. Empirical PPT-ANPP relationships derived from long-term site-based data are almost always portrayed as linear, but recent evidence has accumulated that is inconsistent with an underlying linear relationship. We review, and then reconcile, these inconsistencies with a nonlinear model that incorporates observed asymmetries in PPT-ANPP relationships. Although data are currently lacking for parameterization, this new model highlights research needs that, when met, will improve our understanding of carbon cycle dynamics, as well as forecasts of ecosystem responses to climate change.
authors.affiliation: Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, 80523, USA.
authors.forename: Alan K
authors.initials: AK
authors.lastname: Knapp
authors.affiliation: Laboratoire des Sciences du Climat et de l'Environnement, CEA CNRS UVSQ, Gif-sur-Yvette, 91191, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Ciais
authors.affiliation: Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, 80523, USA.
authors.forename: Melinda D
authors.initials: MD
authors.lastname: Smith
mesh_terms: D057231:Climate Change; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D063245:Plant Development; D011891:Rain; D013997:Time Factors
keywords: carbon cycle; climate change; climate extremes; drought; precipitation; productivity; variability