Hydrological controls on heterotrophic soil respiration across an agricultural landscape

摘要: Abstract Climate change is expected to increase the intensity of precipitation, but our ability model consequences for soil respiration are limited by a lack data from soils that saturated and draining. In this study, we used large intact columns (28 × 30 cm) 1) quantify changes in CO 2 flux as drain conditions, 2) determine which water metrics best predict instantaneous maximum flux. The were three agricultural landscape positions vary properties. We simulated table fluctuations observed at field site (and predicted future climate scenarios) flooding bottom surface then allowing 96 h while monitoring volumetric content (VWC), filled pore space (WFPS), normalized capacity, matric potential, Mean cumulative was 4649 mg ―C m − 2 − 1 . Regardless position, rates exhibited single slightly below saturation, near capacity. This result suggests many studies have not captured when availability optimum heterotrophic respiration. Across positions, potential most consistent indicator flux, with fluxes occurring within narrow range − 0.15 − 4.89 kPa. contrast, occurred between 95 131% 72–97% WFPS, 29–45% VWC. Thus, suggest rates, key parameter ecosystem models, can be across an diverse if scalar.