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Patterns and implications of Plant-soil δ13C and δ15N values in African savanna ecosystems

Published online by Cambridge University Press:  20 January 2017

Lixin Wang*
Affiliation:
Department of Environmental Sciences, University of Virginia, 291 McCormick Road, Charlottesville, VA 22904, USA Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, 08544, USA
Paolo D'Odorico
Affiliation:
Department of Environmental Sciences, University of Virginia, 291 McCormick Road, Charlottesville, VA 22904, USA
Lydia Ries
Affiliation:
Department of Environmental Sciences, University of Virginia, 291 McCormick Road, Charlottesville, VA 22904, USA Bren School of Environmental Science and Management, 3011 Bren Hall, University of California, Santa Barbara, CA 93103, USA
Stephen A. Macko
Affiliation:
Department of Environmental Sciences, University of Virginia, 291 McCormick Road, Charlottesville, VA 22904, USA
*
*Corresponding author. E322 E-Quad Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, 08544, USA. Fax: +1 609 258 2799. E-mail address:lixinw@princeton.edu

Abstract

Southern African savannas are mixed plant communities where C3 trees co-exist with C4 grasses. Here foliar δ15N and δ13C were used as indicators of nitrogen uptake and of water use efficiency to investigate the effect of the rainfall regime on the use of nitrogen and water by herbaceous and woody plants in both dry and wet seasons. Foliar δ15N increased as aridity rose for both C3 and C4 plants for both seasons, although the magnitude of the increase was different for C3 and C4 plants and for two seasons. Soil δ15N also significantly increased with aridity. Foliar δ13C increased with aridity for C3 plants in the wet season but not in the dry season, whereas in C4 plants the relationship was more complex and non-linear. The consistently higher foliar δ15N for C3 plants suggests that C4 plants may be a superior competitor for nitrogen. The different foliar δ13C relationships with rainfall may indicate that the C3 plants have an advantage when competing for water resources. The differences in water and nitrogen use likely collectively contribute to the tree–grass coexistence in savannas. Such differences facilitate interpretations of palaeo-vegetation composition variations and help predictions of vegetation composition changes under future climatic scenarios.

Type
Original Articles
Copyright
University of Washington

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References

Aranibar, J.N., Anderson, I.C., Ringrose, S., Macko, S.A., (2003). Importance of nitrogen fixation in soil crusts of southern African arid ecosystems: acetylene reduction and stable isotope studies. Journal of Arid Environments 54, 345358.CrossRefGoogle Scholar
Aranibar, J.N., Otter, L., Macko, S.A., Feral, C.J.W., Epstein, H.E., Dowty, P.R., Eckardt, F., Shugart, H.H., Swap, R.J., (2004). Nitrogen cycling in the soil-plant system along a precipitation gradient in the Kalahari sands. Global Change Biology 10, 359373.CrossRefGoogle Scholar
Aranibar, J.N., Anderson, I.C., Epstein, H.E., Feral, C.J.W., Swap, R.J., Ramontsho, J., Macko, S.A., (2008). Nitrogen isotope composition of soils, C3 and C4 plants along land use gradients in southern Africa. Journal of Arid Environments 72, 326337. 10.1016/j.jaridenv.2007.06.007CrossRefGoogle Scholar
Austin, A.T., Vitousek, P.M., (1998). Nutrient dynamics on a precipitation gradient in Hawaii. Oecologia 119, 519529.CrossRefGoogle Scholar
Beerling, D.J., Osborne, C.P., (2006). The origin of the savanna biome. Global Change Biology 12, 20232031.CrossRefGoogle Scholar
Bird, M.I., Veenendaal, E.M., Lloyd, J.J., (2004). Soil carbon inventories and δ13C along a moisture gradient in Botswana. Global Change Biology 10, 342349.CrossRefGoogle Scholar
Brady, N.C., Weil, R.R., (1999). The Nature and Properties of Soil. Prentice Hall, Upper Saddle River.Google Scholar
Brenner, D.L., Amundson, R., Baisden, W.T., Kendall, C., Harden, J., (2001). Soil N and N-15 variation with time in a California annual grassland ecosystem. Geochimica et Cosmochimica Acta 65, 41714186.CrossRefGoogle Scholar
Buchmann, N., Brooks, J.R., Rapp, K.D., Ehleringer, J.R., (1996). Carbon isotope composition of C4 grasses is influenced by light and water supply. Plant Cell and Environment 19, 392402.CrossRefGoogle Scholar
Clayton, W.D., (1981). Evolution and distribution of grasses. Annals of the Missouri Botanical Garden 68, 514.CrossRefGoogle Scholar
Farquhar, G., Ehleringer, J., Hubick, K., (1989). Carbon isotope discrimination and photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 40, 503537.CrossRefGoogle Scholar
Feral, C.J.W., Epstein, H.E., Otter, L., Aranibar, J.N., Shugart, H.H., Macko, S.A., Ramontsho, J., (2003). Carbon and nitrogen in the soil-plant system along rainfall and land-use gradients in southern Africa. Journal of Arid Environments 54, 327343.CrossRefGoogle Scholar
Garten, C.T., (1993). Variation in foliar 15N abundance and the availability of soil nitrogen on walker branch watershed. Ecology 74, 20982113.CrossRefGoogle Scholar
Handley, L.L., Scrimgeour, C.M., (1997). Terrestrial plant ecology and 15N natural abundance: the present limits to interpretation for uncultivated systems with original data from a Scottish old field. Begon, M., Fitter, A.H. Advances in Ecological Research 27, Academic Press, San Diego.133212.CrossRefGoogle Scholar
Högberg, P., (1997). 15N natural abundance in soil-plant systems. New Phytologist 137, 179203.CrossRefGoogle ScholarPubMed
Jackson, R., Banner, J., Jobbágy, E., Pockman, W., Wall, D., (2002). Ecosystem carbon loss with woody plant invasion of grasslands. Nature 418, 623626.CrossRefGoogle ScholarPubMed
Jackson, R.B., Jobbagy, E.G., Avissar, R., Roy, S.B., Barrett, D.J., Cook, C.W., Farley, K.A., Maitre, D.C.L., McCarl, B.A., Murray, B.C., (2005). Trading water for carbon with biological carbon sequestration. Science 310, 19441947.CrossRefGoogle ScholarPubMed
Koch, G.W., Scholes, R.J., Steffen, W.L., Vitousek, P.M., Walker, B.H., (1995). The IGBP terrestrial transects: Science plan. Report No. 36. International Geosphere-Biosphere Programme, Stockholm.Google Scholar
Laio, F., Porporato, A., Ridolfi, L., Rodriguez-Iturbe, I., (2001). Plants in water-controlled ecosystems. Active role in hydrological processes and response to water stress. II Probabilistic soil moisture dynamics. Advances in Water Resources 24, 707723.CrossRefGoogle Scholar
Lamb, A.L., Leng, M.J., Mohammed, M.U., Lamb, H.F., (2004). Holocene climate and vegetation change in the Main Ethiopian Rift Valley, inferred from the composition (C/N and δ13C) of lacustrine organic matter. Quaternary Science Reviews 23, 881891.CrossRefGoogle Scholar
Raven, P.H., Axelrod, D.I., (1974). Angiosperm biogeography and past continental movements. Annals of the Missouri Botanical Garden 61, 539673.CrossRefGoogle Scholar
Robinson, D., (2001). δ15N as an integrator of the nitrogen cycle. Trends in Ecology and Evolution 16, 153162.CrossRefGoogle ScholarPubMed
Roques, K.G., O, , Connor, T.G., Watkinson, A.R., (2001). Dynamics of shrub encroachment in an African savanna: relative influences of fire, herbivory, rainfall and density dependence. Journal of Applied Ecology 38, 268280.CrossRefGoogle Scholar
Sah, S.P., Rita, H., Ilvesniemi, H., (2006). 15N natural abundance of foliage and soil across boreal forests of Finland. Biogeochemistry 80, 307318.CrossRefGoogle Scholar
Sankaran, M., Hanan, N.P., Scholes, R.J., Ratnam, J., Augustine, D.J., Cade, B.S., Gignoux, J., Higgins, S.I., Roux, X.L., Ludwig, F., Ardo, J., Banyikwa, F., Bronn, A., Bucini, G., Caylor, K.K., Coughenour, M.B., Diouf, A., Ekaya, W., Feral, C.J., February, E.C., Frost, P.G.H., Hiernaux, P., Hrabar, H., Metzger, K.L., Prins, H.H.T., Ringrose, S., Sea, W., Tews, J., Worden, J., Zambatis, N., (2005). Determinants of woody cover in African savannas. Nature 438, 846849.CrossRefGoogle ScholarPubMed
Sarmiento, G., (1984). The Ecology of Neotropical Savannas. Harvard University Press, Cambridge, MA.CrossRefGoogle Scholar
Scholes, R.J., Walker, B.H., (1993). An African Savanna. Cambridge University Press, .CrossRefGoogle Scholar
Scholes, R.J., Archer, S.R., (1997). Tree–grass interactions in savannas. Annual Review of Ecology and Systematics 28, 517544.CrossRefGoogle Scholar
Sinclair, A., (1979). Dynamics of the Serengeti ecosystem. Sinclair, A., Norton-Griffiths, M. Serengeti: Dynamics of an Ecosystem.University of Chicago Press, Chicago.130.Google Scholar
Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K., Tignor, M., Miller, H., (2007). IPCC, 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge and New York.Google Scholar
Swap, R.J., Aranibar, J.N., Dowty, P.R., Gilhooly, W.P., Macko, S.A., (2004). Natural abundance of 13C and 15N in C3 and C4 vegetation of southern Africa: patterns and implications. Global Change Biology 10, 350358.CrossRefGoogle Scholar
Thomas, A.D., Hoon, S.R., Linton, P.E., (2008). Carbon dioxide fluxes from cyanobacteria crusted soils in the Kalahari. Applied Soil Ecology 39, 254263.CrossRefGoogle Scholar
Thomas, D.S.G., Knight, M., Wiggs, G.F.S., (2005). Remobilization of southern African desert dune systems by twenty-first century global warming. Nature 435, 12181221.CrossRefGoogle ScholarPubMed
Vivo, M.D., Carmignotto, A.P., (2004). Holocene vegetation change and the mammal faunas of South America and Africa. Journal of Biogeography 31, 943957.CrossRefGoogle Scholar
Wang, L., D, , Odorico, P., Ringrose, S., Coetzee, S., Macko, S., (2007a). Biogeochemistry of Kalahari sands. Journal of Arid Environments 71, 259279. 10.1016/j.jaridenv.2007.03.016CrossRefGoogle Scholar
Wang, L., Okin, G.S., Wang, J., Epstein, H., Macko, S.A., (2007b). Predicting leaf and canopy 15N compositions from reflectance spectra. Geophysical Research Letters 34, L02401 10.1029/2006GL028506Google Scholar
Wang, L., Shaner, P.-J.L., Macko, S., (2007c). Foliar δ15N patterns along successional gradients at plant community and species levels. Geophysical Research Letters 34, L16403 10.1029/2007GL030722CrossRefGoogle Scholar
Wang, L., (2008). Soil biogeochemistry, aridity and plant adaptation responses in southern Africa savannas. PhD dissertation. University of Virginia, Charlottesville, USA.Google Scholar
Wang, L., D’Odorico, P., Okin, G., Macko, S., (2009). Isotope composition and anion chemistry of soil profiles along the Kalahari Transect. Journal of Arid Environments 73, 480486.CrossRefGoogle Scholar