Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework

Land use and management practices affect the response of soil organic carbon (C) to global change. Process-based models of soil C are useful tools to simulate C dynamics, but it is important to bridge any disconnect that exists between the data used to inform the models and the processes that they d...

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Main Authors: Lee, Juhwan, Viscarra Rossel, Raphael, Zhang, Mingxi, Luo, Z., Wang, Y.P.
Format: Journal Article
Language:English
Published: COPERNICUS GESELLSCHAFT MBH 2021
Subjects:
Online Access:http://purl.org/au-research/grants/arc/DP210100420
http://hdl.handle.net/20.500.11937/90876
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author Lee, Juhwan
Viscarra Rossel, Raphael
Zhang, Mingxi
Luo, Z.
Wang, Y.P.
author_facet Lee, Juhwan
Viscarra Rossel, Raphael
Zhang, Mingxi
Luo, Z.
Wang, Y.P.
author_sort Lee, Juhwan
building Curtin Institutional Repository
collection Online Access
description Land use and management practices affect the response of soil organic carbon (C) to global change. Process-based models of soil C are useful tools to simulate C dynamics, but it is important to bridge any disconnect that exists between the data used to inform the models and the processes that they depict. To minimise that disconnect, we developed a consistent modelling framework that integrates new spatially explicit soil measurements and data with the Rothamsted carbon model (Roth C) and simulates the response of soil organic C to future climate change across Australia. We compiled publicly available continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated Roth C and ran simulations to estimate the baseline soil organic C stocks and composition in the 0-0.3m layer at 4043 sites in cropping, modified grazing, native grazing and natural environments across Australia. We used data on the C fractions, the particulate, mineral-associated and resistant organic C (POC, MAOC and ROC, respectively) to represent the three main C pools in the Roth C model's structure. The model explained 97%-98% of the variation in measured total organic C in soils under cropping and grazing and 65% in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to simulate the potential for C accumulation under constant climate in a 100-year simulation. With an annual increase of 1MgCha-1 in C inputs, the model simulated a potential soil C increase of 13.58 (interquartile range 12.19-15.80), 14.21 (12.38-16.03) and 15.57 (12.07-17.82)MgCha-1 under cropping, modified grazing and native grazing and 3.52 (3.15-4.09)MgCha-1 under natural environments. With projected future changes in climate (+1.5, 2 and 5.0°C) over 100 years, the simulations showed that soils under natural environments lost the most C, between 3.1 and 4.5MgCha-1, while soils under native grazing lost the least, between 0.4 and 0.7MgCha-1. Soil under cropping lost between 1 and 2.7MgCha-1, while those under modified grazing showed a slight increase with temperature increases of 1.5°C, but with further increases of 2 and 5°C the median loss of TOC was 0.28 and 3.4MgCha-1, respectively. For the different land uses, the changes in the C fractions varied with changes in climate. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C:N ratio and cropping were the most important controls on POC change. Clay content and climate were dominant controls on MAOC change. Consistent and explicit soil organic C simulations improve confidence in the model's estimations, facilitating the development of sustainable soil management under global change.
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format Journal Article
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institution Curtin University Malaysia
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language English
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publishDate 2021
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spelling curtin-20.500.11937-908762023-05-09T03:27:08Z Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework Lee, Juhwan Viscarra Rossel, Raphael Zhang, Mingxi Luo, Z. Wang, Y.P. Science & Technology Life Sciences & Biomedicine Physical Sciences Ecology Geosciences, Multidisciplinary Environmental Sciences & Ecology Geology ORGANIC-CARBON TERRESTRIAL CARBON ROTHC MODEL MATTER CALIBRATION TURNOVER STOCKS SEQUESTRATION SIMULATIONS UNCERTAINTY Land use and management practices affect the response of soil organic carbon (C) to global change. Process-based models of soil C are useful tools to simulate C dynamics, but it is important to bridge any disconnect that exists between the data used to inform the models and the processes that they depict. To minimise that disconnect, we developed a consistent modelling framework that integrates new spatially explicit soil measurements and data with the Rothamsted carbon model (Roth C) and simulates the response of soil organic C to future climate change across Australia. We compiled publicly available continental-scale datasets and pre-processed, standardised and configured them to the required spatial and temporal resolutions. We then calibrated Roth C and ran simulations to estimate the baseline soil organic C stocks and composition in the 0-0.3m layer at 4043 sites in cropping, modified grazing, native grazing and natural environments across Australia. We used data on the C fractions, the particulate, mineral-associated and resistant organic C (POC, MAOC and ROC, respectively) to represent the three main C pools in the Roth C model's structure. The model explained 97%-98% of the variation in measured total organic C in soils under cropping and grazing and 65% in soils under natural environments. We optimised the model at each site and experimented with different amounts of C inputs to simulate the potential for C accumulation under constant climate in a 100-year simulation. With an annual increase of 1MgCha-1 in C inputs, the model simulated a potential soil C increase of 13.58 (interquartile range 12.19-15.80), 14.21 (12.38-16.03) and 15.57 (12.07-17.82)MgCha-1 under cropping, modified grazing and native grazing and 3.52 (3.15-4.09)MgCha-1 under natural environments. With projected future changes in climate (+1.5, 2 and 5.0°C) over 100 years, the simulations showed that soils under natural environments lost the most C, between 3.1 and 4.5MgCha-1, while soils under native grazing lost the least, between 0.4 and 0.7MgCha-1. Soil under cropping lost between 1 and 2.7MgCha-1, while those under modified grazing showed a slight increase with temperature increases of 1.5°C, but with further increases of 2 and 5°C the median loss of TOC was 0.28 and 3.4MgCha-1, respectively. For the different land uses, the changes in the C fractions varied with changes in climate. An empirical assessment of the controls on the C change showed that climate, pH, total N, the C:N ratio and cropping were the most important controls on POC change. Clay content and climate were dominant controls on MAOC change. Consistent and explicit soil organic C simulations improve confidence in the model's estimations, facilitating the development of sustainable soil management under global change. 2021 Journal Article http://hdl.handle.net/20.500.11937/90876 10.5194/bg-18-5185-2021 English http://purl.org/au-research/grants/arc/DP210100420 http://creativecommons.org/licenses/by/4.0/ COPERNICUS GESELLSCHAFT MBH fulltext
spellingShingle Science & Technology
Life Sciences & Biomedicine
Physical Sciences
Ecology
Geosciences, Multidisciplinary
Environmental Sciences & Ecology
Geology
ORGANIC-CARBON
TERRESTRIAL CARBON
ROTHC MODEL
MATTER
CALIBRATION
TURNOVER
STOCKS
SEQUESTRATION
SIMULATIONS
UNCERTAINTY
Lee, Juhwan
Viscarra Rossel, Raphael
Zhang, Mingxi
Luo, Z.
Wang, Y.P.
Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework
title Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework
title_full Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework
title_fullStr Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework
title_full_unstemmed Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework
title_short Assessing the response of soil carbon in Australia to changing inputs and climate using a consistent modelling framework
title_sort assessing the response of soil carbon in australia to changing inputs and climate using a consistent modelling framework
topic Science & Technology
Life Sciences & Biomedicine
Physical Sciences
Ecology
Geosciences, Multidisciplinary
Environmental Sciences & Ecology
Geology
ORGANIC-CARBON
TERRESTRIAL CARBON
ROTHC MODEL
MATTER
CALIBRATION
TURNOVER
STOCKS
SEQUESTRATION
SIMULATIONS
UNCERTAINTY
url http://purl.org/au-research/grants/arc/DP210100420
http://hdl.handle.net/20.500.11937/90876