Soil Carbon pp 219-227
Is Percent ‘Projected Natural Vegetation Soil Carbon’ a Useful Indicator of Soil Condition?
- First Online:
The concentration of Soil Organic Carbon (SOC) is often used as an indicator of soil condition and soil health. To be useful as an indicator, SOC must be considered in context, with soil type, climatic region, local rainfall, slope, and land use history influencing measured amounts of SOC. The concept of Percent Projected Natural Vegetation Soil Carbon (PNVSC) implicitly incorporates these context variables. Percent PNVSC is defined as a simple percentage comparing the contemporary measured soil carbon against a hypothetical amount of soil carbon that would be observed in the local landscape today, if the areas under managed agroecosystems remained under natural vegetation (which in this study is dry sclerophyll forest). The term ‘natural’ used in the PNVSC concept approximates with the natural system prior to agrarian settlement. Percent PNVSC was calculated for a 22,000 ha sub-catchment of the Hunter Valley, Australia and it showed a spatially weighted average of 73, indicating substantial soil carbon loss as a result of cumulative land use change over more than 100 years. The Percent PNVSC map highlights changes in soil carbon distribution across the landscape with mid-slope positions lower in the catchment showing the greatest loss of soil carbon. Viticulture has resulted in half of the original SOC being lost, compared to a 75 % PNVSC for unimproved pasture and an 83 % PNVSC for improved pasture. Average soil carbon loss due to mixed land-use change in this sub-catchment is 13,331 kg C/ha.
KeywordsPercent Projected Natural Vegetation Soil Carbon Percent PNVSC Soil carbon Soil health Soil quality Soil impact map Land use impact
- Coleman K, Jenkinson DS (1999) The Rothamsted carbon model webpage. http://www.rothamsted.ac.uk/ssgs/RothC/RothC.php. Accessed May 2013
- Isbell RF, McDonald WS, Ashton LJ (1997) Concepts and rationale of the Australian soil classification. ACLEP, CSIRO Land and Water, CanberraGoogle Scholar
- IUSS Working Group WRB (2007) World reference base for soil resources 2006. First update 2007. World Soil Resources Report No. 103. FAO, RomeGoogle Scholar
- Jenkins A (2006) Northern rivers Soil Health Card: a monitoring tool for farmers developed by farmers. In: Proceedings of the APEN international conference, Practice change for sustainable communities: exploring footprints, pathways and possibilities, 6–8 March 2006, Beechworth, Australia. http://www.regional.org.au/au/apen/2006/refereed/1/3157_jenkinsa.htm. Accessed May 2013
- McKenzie N, Coughlan K, Cresswell H (eds) (2002) Soil physical measurement and determination for land evaluation. CSIRO Publishing, CollingwoodGoogle Scholar
- Stabile M (2011) Deconstructing the complexity of land use and cover classification and land change modelling. Unpublished PhD thesis, University of SydneyGoogle Scholar
- United States Department of Agriculture (2002) Interpreting the soil conditioning index: a tool for measuring soil organic matter trends, Soil quality – Agronomy Technical Note No. 16. Soil Quality Institute, National Soil Conservation Service, United States Department of Agriculture, AuburnGoogle Scholar
- United States Department of Agriculture (2012) Soil quality – Improving how your soil works. National Resources and Conservation Service, United States Department of Agriculture. Last update October 2012. http://www.soils.usda.gov/sqi/