Changes in soil moisture drive soil methane uptake along a fire regeneration chronosequence in a eucalypt forest landscape

• DOI: 10.1111/gcb.13003
• Publication Date: 2015-06-18T14:18:01Z
• Authors: Benedikt Fest; Tim Wardlaw; Stephen J. Livesley; Thomas J. Duff; Stefan K. Arndt
• Keywords: Chronosequence; Clearcutting; Soil carbon

Abstract Disturbance associated with severe wildfires (WF) and WF simulating harvest operations can potentially alter soil methane ( CH 4 ) oxidation in well‐aerated forest soils due to the effect on properties linked diffusivity, methanotrophic activity or changes bacterial community structure. However, flux related such disturbances are still rarely studied even though frequency is predicted increase as a consequence of global climate change. We measured in‐situ soil–atmosphere exchange along wet sclerophyll eucalypt regeneration chronosequence Tasmania, Australia, where time since last fire harvesting disturbance ranged from 9 >200 years. On all sampling occasions, mean uptake increased most recently disturbed sites (9 year) at stand ‘maturity’ (44 76 years). In stands >76 years disturbance, we observed decrease uptake. A similar age dependency potential for three layers (0.0–0.05, 0.05–0.10, 0.10–0.15 m) could be incubated under controlled laboratory conditions. The differences between different were predominantly driven by moisture status, which affected diffusion atmospheric into soil. pattern was likely interception evapotranspiration age, have been well described systems south‐eastern Australia. Our results imply that there large amount variability landscape scale attributed differences. An response change overall sinks.