Abstract
A readily applied quantitative relationship between topsoil organic carbon levels and several major soil forming factors has been developed over eastern Australia using a dataset of 3652 soil profiles. The key soil forming covariates used were (i) climate: annual precipitation (precip) and annual maximum temperature (Tmax) (ii) parent material: assumed silica content, (iii) topography: a new "toposlope" index and (iv) land use: a modified land disturbance index (LDI). The multiple regression relationship, with soil organic carbon (orgC) on the natural log scale, achieved an R2 value of 0.54 with a residual standard error of loge 0.58 orgC%. Validation against 10% of points initially withheld revealed a root mean square error of 1.77 orgC% (on original non-log scale) and a median absolute error of 0.75 orgC%. Topsoil organic carbon levels appear to be predominantly controlled by maximum temperatures followed by precipitation and parent material composition with topography and land use being of lesser significance. The model is of moderate statistical strength and may provide a pragmatic tool for modelling and first approximation prediction of organic carbon levels in topsoils of eastern Australia.
Original language | English |
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Title of host publication | Digital soil assessments and beyond |
Subtitle of host publication | proceedings of the 5th Global Workshop on Digital Soil Mapping, 2012, Sydney, Australia, 10-13 April 2012 |
Editors | Budiman Minasny, Brendan P. Malone, Alex B. McBratney |
Place of Publication | Leiden, The Netherlands |
Publisher | CRC Press, Taylor & Francis Group |
Pages | 115-120 |
Number of pages | 6 |
ISBN (Electronic) | 9780203106105 |
ISBN (Print) | 9780415621557 |
DOIs | |
Publication status | Published - 2012 |
Externally published | Yes |
Event | 5th Global Workshop on Digital Soil Mapping - Sydney, NSW, Australia Duration: 10 Apr 2012 → 13 Apr 2012 |
Other
Other | 5th Global Workshop on Digital Soil Mapping |
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Country/Territory | Australia |
City | Sydney, NSW |
Period | 10/04/12 → 13/04/12 |