Plant stable isotope composition across habitat gradients in a semi-arid savanna: implications for environmental reconstruction
Article first published online: 23 APR 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Journal of Quaternary Science
Volume 28, Issue 3, pages 301–310, April 2013
How to Cite
CODRON, J., LEE-THORP, J. A., SPONHEIMER, M. and CODRON, D. (2013), Plant stable isotope composition across habitat gradients in a semi-arid savanna: implications for environmental reconstruction. J. Quaternary Sci., 28: 301–310. doi: 10.1002/jqs.2614
- Issue published online: 23 APR 2013
- Article first published online: 23 APR 2013
- Manuscript Accepted: 2 DEC 2012
- Manuscript Revised: 17 OCT 2012
- Manuscript Received: 23 MAY 2012
- C3 plants;
- C4 plants;
- Kruger National Park;
Field studies of plant stable carbon and nitrogen isotope composition have revealed relationships with temperature and precipitation. These relationships conform to theoretical predictions of how extrinsic factors impact on ecophysiological processes such as photosynthesis and nitrogen cycling. However, examination of many datasets reveals high levels of variation, especially across environments with moderate precipitation (<1000 mm a−1). To test for extrinsic effects on plant isotope composition in such environments, we studied data from plants collected over three years from multiple habitats and seasons in Kruger National Park, South Africa. Our sample is sufficiently large to evaluate not only effects of environmental variables (rainfall up to ∼800 mm a−1, temperature, physical habitat structure) but also taxonomic effects. Species composition of habitats accounted for most of the variation in our data, followed by physical habitat structure (e.g. wooded or riverine compared with open, grassy habitats), while rainfall and temperature had only indirect or negligible effects. The latter finding concurs with subsections of existing datasets and we suggest therefore that such effects usually become visible in datasets that span environmental extremes, implying environmental ranges within which plant isotope variations cannot readily be ascribed to climate. Copyright © 2013 John Wiley & Sons, Ltd.