Response of terrestrial net primary productivity to precipitation extremes: Patterns, mechanisms, and uncertainties

Abstract

Abstract Climate change forecasts include intensified precipitation (PPT) extremes at both inter and intraannual timescales. Terrestrial net primary productivity (NPP) is sensitive to water availability generally and, presumably, PPT extremes especially. Evidence suggests NPP in dry regions to be especially sensitive to PPT extremes. However, evidence also suggests that PPT extremes often do not produce large impacts to NPP; related to ecological contingencies, such as vegetation dynamics and characteristics of PPT extremes, which mediate PPT-NPP interactions. Understanding emergent consequences of these contingencies for NPP requires innovation in studying ecosystem responses to PPT extremes. Cross-site and long-term experimental networks with experimental designs that impose broad PPT gradients—especially those with PPT extremes—are recommended. Having the design of these experiments be codeveloped and guided by uncertainties and needs in process-based modeling can accelerate model improvements by constraining model parameters and assumptions with empirical observations. The fusion of these different research approaches into one can guide the next generation of research on ecosystem responses to PPT extremes.