Response of soil carbon dioxide efflux to temporal repackaging of rainfall into fewer, larger events in a semiarid grassland

Changing rainfall patterns will alter soil water availability to plants and microbes likely impact CO 2 efflux (F s ) in semiarid ecosystems. However, our understanding of the response F compound changes event size frequency remains relatively limited. To address this knowledge gap, we examined how a grassland by deploying automated chambers at manipulation experiment. All plots within experiment received equal total summer growing season precipitation that was temporally repackaged into regular events inversely varied frequency, with sizes ranging from 5 50 mm dry intervals 3.5 21 days. We found repackaging few/large long decreased seasonal cumulative . Repackaging influenced key aspects pulses including mean, maximum, antecedent (day before irrigation) values moisture their rate decline during drying intervals. Soil explained substantial variation (R > 0.84) for all treatments; however, sensitivity regime compared reference many/small regimes. Dynamics plant phenology (quantified plot greenness) temperature interacted influence evolution efflux. Our findings demonstrate vegetation responses emissions grasslands. These results, coupled play an outsized role dryland carbon exchange, indicate possibility future climate-mediated shifts cycling