Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change

We can effectively monitor soil condition-and develop sound policies to offset the emissions of greenhouse gases-only with accurate data from which to define baselines. Currently, estimates of soil organic C for countries or continents are either unavailable or largely uncertain because they are der...

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Main Authors: Viscarra Rossel, Raphael, Webster, R., Bui, E., Baldock, J.
Format: Journal Article
Published: Blackwell Publishing 2014
Online Access:http://hdl.handle.net/20.500.11937/73771
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author Viscarra Rossel, Raphael
Webster, R.
Bui, E.
Baldock, J.
author_facet Viscarra Rossel, Raphael
Webster, R.
Bui, E.
Baldock, J.
author_sort Viscarra Rossel, Raphael
building Curtin Institutional Repository
collection Online Access
description We can effectively monitor soil condition-and develop sound policies to offset the emissions of greenhouse gases-only with accurate data from which to define baselines. Currently, estimates of soil organic C for countries or continents are either unavailable or largely uncertain because they are derived from sparse data, with large gaps over many areas of the Earth. Here, we derive spatially explicit estimates, and their uncertainty, of the distribution and stock of organic C in the soil of Australia. We assembled and harmonized data from several sources to produce the most comprehensive set of data on the current stock of organic C in soil of the continent. Using them, we have produced a fine spatial resolution baseline map of organic C at the continental scale. We describe how we made it by combining the bootstrap, a decision tree with piecewise regression on environmental variables and geostatistical modelling of residuals. Values of stock were predicted at the nodes of a 3-arc-sec (approximately 90 m) grid and mapped together with their uncertainties. We then calculated baselines of soil organic C storage over the whole of Australia, its states and territories, and regions that define bioclimatic zones, vegetation classes and land use. The average amount of organic C in Australian topsoil is estimated to be 29.7 t ha-1 with 95% confidence limits of 22.6 and 37.9 t ha-1. The total stock of organic C in the 0-30 cm layer of soil for the continent is 24.97 Gt with 95% confidence limits of 19.04 and 31.83 Gt. This represents approximately 3.5% of the total stock in the upper 30 cm of soil worldwide. Australia occupies 5.2% of the global land area, so the total organic C stock of Australian soil makes an important contribution to the global carbon cycle, and it provides a significant potential for sequestration. As the most reliable approximation of the stock of organic C in Australian soil in 2010, our estimates have important applications. They could support Australia's National Carbon Accounting System, help guide the formulation of policy around carbon offset schemes, improve Australia's carbon balances, serve to direct future sampling for inventory, guide the design of monitoring networks and provide a benchmark against which to assess the impact of changes in land cover, land management and climate on the stock of C in Australia. In this way, these estimates would help us to develop strategies to adapt and mitigate the effects of climate change.
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spelling curtin-20.500.11937-737712019-08-15T08:26:50Z Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change Viscarra Rossel, Raphael Webster, R. Bui, E. Baldock, J. We can effectively monitor soil condition-and develop sound policies to offset the emissions of greenhouse gases-only with accurate data from which to define baselines. Currently, estimates of soil organic C for countries or continents are either unavailable or largely uncertain because they are derived from sparse data, with large gaps over many areas of the Earth. Here, we derive spatially explicit estimates, and their uncertainty, of the distribution and stock of organic C in the soil of Australia. We assembled and harmonized data from several sources to produce the most comprehensive set of data on the current stock of organic C in soil of the continent. Using them, we have produced a fine spatial resolution baseline map of organic C at the continental scale. We describe how we made it by combining the bootstrap, a decision tree with piecewise regression on environmental variables and geostatistical modelling of residuals. Values of stock were predicted at the nodes of a 3-arc-sec (approximately 90 m) grid and mapped together with their uncertainties. We then calculated baselines of soil organic C storage over the whole of Australia, its states and territories, and regions that define bioclimatic zones, vegetation classes and land use. The average amount of organic C in Australian topsoil is estimated to be 29.7 t ha-1 with 95% confidence limits of 22.6 and 37.9 t ha-1. The total stock of organic C in the 0-30 cm layer of soil for the continent is 24.97 Gt with 95% confidence limits of 19.04 and 31.83 Gt. This represents approximately 3.5% of the total stock in the upper 30 cm of soil worldwide. Australia occupies 5.2% of the global land area, so the total organic C stock of Australian soil makes an important contribution to the global carbon cycle, and it provides a significant potential for sequestration. As the most reliable approximation of the stock of organic C in Australian soil in 2010, our estimates have important applications. They could support Australia's National Carbon Accounting System, help guide the formulation of policy around carbon offset schemes, improve Australia's carbon balances, serve to direct future sampling for inventory, guide the design of monitoring networks and provide a benchmark against which to assess the impact of changes in land cover, land management and climate on the stock of C in Australia. In this way, these estimates would help us to develop strategies to adapt and mitigate the effects of climate change. 2014 Journal Article http://hdl.handle.net/20.500.11937/73771 10.1111/gcb.12569 Blackwell Publishing restricted
spellingShingle Viscarra Rossel, Raphael
Webster, R.
Bui, E.
Baldock, J.
Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change
title Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change
title_full Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change
title_fullStr Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change
title_full_unstemmed Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change
title_short Baseline map of organic carbon in Australian soil to support national carbon accounting and monitoring under climate change
title_sort baseline map of organic carbon in australian soil to support national carbon accounting and monitoring under climate change
url http://hdl.handle.net/20.500.11937/73771