Journal Article
Drought and Warming‐Induced Drying Suppress Soil Respiration but Amplify Rewetting‐Induced Pulses in a Temperate Pasture
Pankaj Tiwari; Elise Pendall; Nicholas Wright‐Osment; Nor Azizah Kusai; Manjunatha H. Chandregowda; Awais Shakoor; Debjani Sihi; Sally A. Power; Eric A. Davidson; Catriona A. Macdonald
Global Change Biology · Vol. 32, Issue 7 · 2026
Abstract
As climate extremes intensify, interactions among environmental drivers are expected to alter soil respiration (SR) and its response to rewetting, increasing uncertainty in carbon‐climate feedbacks. However, the interactive effects of drought and warming, two commonly studied climate stressors, on SR remain elusive due to limited research and a lack of high‐resolution data. This study investigated overall SR (SR overall , encompassing both drying and rewetting phases) and rewetting‐induced respiration pulses (SR pulse ), along with their apparent sensitivity to temperature and moisture under factorial combinations of rainfall and warming treatments in a field‐based climate‐manipulation experiment conducted in a temperate pasture system in southeastern Australia. Rainfall extremes were derived from 30 years of regional climate records, while warming was imposed as a continuous, year‐round increase of +3°C. An automated flux monitoring system was deployed to measure hourly SR across eight campaigns from October 2023 to November 2024. The drivers of SR overall and SR pulse were identified by analyzing climatic variables together with soil parameters from rhizosphere and non‐rhizosphere zones. Drought and warming consistently suppressed SR overall but amplified SR pulse and moisture sensitivity. The interactive effects of both treatments on SR overall varied seasonally, shifting from additive in spring to antagonistic in summer and autumn, and synergistic in winter. Drought suppressed apparent temperature sensitivity (Q 10 ), but warming effects on Q 10 varied with moisture conditions. Soil temperature, moisture, and extractable C:N ratio from across rhizosphere and non‐rhizosphere soil were consistent predictors of SR overall and SR pulse but exerted opposing effects on the two components. These findings advance our understanding of how drought‐warming interactions shape both overall and pulse‐driven SR, providing a process‐based foundation for improving predictions of carbon‐climate feedbacks under intensifying climate extremes.