Journal article
The impact of shifting Köppen-Geiger climate zones on soil organic carbon concentrations in Australian grasslands
Global and Planetary Change, Vol.202, p.103523
07/2021
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Source: InCites
Abstract
The factors determining the spatial distribution of soil organic carbon (SOC) at large-scales closely align with bioclimate regions; reflecting climate, ecosystem and soil properties. Recent studies of the Köppen-Geiger climate zones of Australia have highlighted an extension of the hot, arid, steppe environment from central Australia into the southeast (SE) under future climate change scenarios (2071–2100 under RCP 8.5). As SOC concentrations are highest in Australia's SE, it is important the effect of this shift is quantified. This study assesses this and how changes in the factors that control SOC formation may alter SOC concentrations. Field measured SOC concentrations were compared to current climate, soil, topography, vegetation, and soil erosion variables for 12 grassland sites from SE to NW Australia. SOC concentrations ranged from 0.39% in northwest (NW) and Central Australia to as high as 6.88% in the SE. Using regression analyses; temperature, elevation and Normalised Difference Vegetation Index were found to be the only significant drivers (α = 0.95) of SOC across the sites. Partial correlation analyses then identified temperature, elevation and clay content as imparting a significant effect on the relationships between SOC and water availability variables. This indicates that an extension of the arid environment into SE Australia may lead to a decrease in SOC (up to 1.12%), as mean annual temperature exceeds threshold values that limit SOC concentration. This is significant as the majority of Australia's SOC is stored in this area and these environments exert a strong influence on global carbon cycling.
•Temperature is a major control soil organic carbon at a national scale.•Field data was collected from 12 grassland sites across Australia.•Soil organic carbon concentrations are linked to Köppen-Geiger climate class.•Warming under climate change will shift Australia's climate zones.•Temperate sites will cross thresholds limiting soil organic carbon concentration.
Details
- Title
- The impact of shifting Köppen-Geiger climate zones on soil organic carbon concentrations in Australian grasslands
- Creators
- A.J Gibson - University of Newcastle AustraliaG.R Hancock - University of Newcastle AustraliaD.C Verdon-Kidd - University of Newcastle AustraliaC Martinez - School of Agriculture and Food Sciences, The University of Queensland, AustraliaT Wells - University of Newcastle Australia
- Publication Details
- Global and Planetary Change, Vol.202, p.103523
- Publisher
- Elsevier B.V
- Identifiers
- 991012995594702368
- Academic Unit
- Faculty of Science and Engineering
- Language
- English
- Resource Type
- Journal article