Skip to main content
SpringerLink
Log in

Overlap in nitrogen sources and redistribution of nitrogen between trees and grasses in a semi-arid savanna

  • Physiological ecology - Original research
  • Published:
Oecologia Aims and scope Submit manuscript

Abstract

A key question in savanna ecology is how trees and grasses coexist under N limitation. We used N stable isotopes and N content to study N source partitioning across seasons from trees and associated grasses in a semi-arid savanna. We also used 15N tracer additions to investigate possible redistribution of N by trees to grasses. Foliar stable N isotope ratio (δ15N) values were consistent with trees and grasses using mycorrhiza-supplied N in all seasons except in the wet season when they switched to microbially fixed N. The dependence of trees and grasses on mineralized soil N seemed highly unlikely based on seasonal variation in mineralization rates in the Kruger Park region. Remarkably, foliar δ15N values were similar for all three tree species differing in the potential for N fixation through nodulation. The tracer experiment showed that N was redistributed by trees to understory grasses in all seasons. Our results suggest that the redistribution of N from trees to grasses and uptake of N was independent of water redistribution. Although there is overlap of N sources between trees and grasses, dependence on biological sources of N coupled with redistribution of subsoil N by trees may contribute to the coexistence of trees and grasses in semi-arid savannas.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3

Similar content being viewed by others

References

  • Abbadie L, Mariotti A, Menaut J (1992) Independance of savanna grasses from soil organic matter for their nitrogen supply. Ecology 73:608–613

    Article  Google Scholar 

  • Aranibar JN, Anderson IC, Epstein HE, Feral CJW, Swap RJ, Ramontsho J, Macko SA (2008) Nitrogen isotope composition of soils, C3 and C4 plants along land use gradients in southern Africa. J Arid Environ 72:326–337. doi:10.1016/j.jaridenv.2007.06.007

    Article  Google Scholar 

  • Archibald S, Scholes RJ (2007) Leaf green-up in a semi-arid African savanna—separating tree and grass responses to environmental cues. J Veg Sci 18:583–594. doi:10.1658/1100-9233(2007) (18 [583:LGIASA]2.0.CO;2)

    Google Scholar 

  • Coetsee C, February EC, Bond WJ (2008) Nitrogen availability is not affected by frequent fire in a South African savanna. J Trop Ecol 24:647–654. doi:10.1017/S026646740800549X

    Article  Google Scholar 

  • Cole MM (1986) The Savannas: biogeography and geobotany. Academic Press, New York

    Google Scholar 

  • Cooke JEK, Weih M (2005) Nitrogen storage and seasonal nitrogen cycling in populus: bridging molecular physiology and ecophysiology. New Phytol 167:19–30. doi:10.1111/j.1469-8137.2005.01451.x

    Article  CAS  PubMed  Google Scholar 

  • Craine JM, Elmore AJ, Aidar MPM, Bustamante M, Dawson TE, Hobbie EA, Kahmen A, Mack MC, McLauchlan KK, Michelsen A, Nardoto GB, Pardo LH, Peñuelas J, Reich PB, Schuur EAG, Stock WD, Templer PH, Virginia RA, Welker JM, Wright IJ (2009a) Global patterns of foliar nitrogen isotopes and their relationships with climate, mycorrhizal fungi, foliar nutrient concentrations, and nitrogen availability. New Phytol 183:980–992. doi:10.1111/j.1469-8137.2009.02917.x

    Article  CAS  PubMed  Google Scholar 

  • Craine JM, Ballantyne F, Peel M, Zambatis N, Morrow C, Stock WD (2009b) Grazing and landscape controls on nitrogen availability across 330 South African savanna sites. Austral Ecol 34:731–740. doi:10.1111/j.1442-9993.2009.01978.x

    Article  Google Scholar 

  • Danckwerts JE, Gordon AJ (1990) Partitioning, storage and remobilization of 14C assimilated by Themeda triandra Forssk. Afr J Range Forage Sci 7:97–105

    Google Scholar 

  • Dybzinski R, Tilman D (2007) Resource use patterns predict long-term outcomes of plant competition for nutrients and light. Am Nat 170:305–318. doi:10.1086/519857

    Article  PubMed  Google Scholar 

  • Eksteen J, Nkosi S (2009) Andover 2009 game count

  • Fargione J, Tilman D (2005) Niche differences in phenology and rooting depth promote coexistence with a dominant C4 bunchgrass. Oecologia 143:598–606. doi:10.1007/s00442-005-0010-y

    Article  PubMed  Google Scholar 

  • February EC, Higgins SI (2010) The distribution of tree and grass roots in savannas in relation to soil nitrogen and water. S Afr J Bot 76:517–523. doi:10.1016/j.sajb.2010.04.001

    Article  Google Scholar 

  • Frak E, Le Roux X, Millard P, Guillaumie S, Wendler R (2006) Nitrogen availability, local light regime and leaf rank effects on the amount and sources of N allocated within the foliage of young walnut (Juglans nigra × regia) trees. Tree Physiol 26:43–49

    Article  CAS  PubMed  Google Scholar 

  • Gathumbi SM, Cadisch G, Buresh RJ, Giller KE (2003) Subsoil nitrogen capture in mixed legume stands as assessed by deep nitrogen-15 placement. Soil Sci Soc Am J 67:573–582

    Article  CAS  Google Scholar 

  • Gaye CB, Edmunds WM (1996) Groundwater recharge estimation using chloride, stable isotopes and tritium profiles in the sands of northwestern Senegal. Environ Geol 27:246–251

    Article  Google Scholar 

  • Gebauer RLE, Ehleringer JR (2000) Water and nitrogen uptake patterns following moisture pulses in a cold desert community. Ecology 81:1415–1424. doi:10.1890/0012-9658(2000) (081 [1415:WANUPF]2.0.CO;2)

    Article  Google Scholar 

  • Glass AD (2005) Homeostatic processes for the optimization of nutrient absorption: Physiology and molecular ecology. In: Bassirirad H (ed) Nutrient acquisition by plants. Springer, Heidelberg, pp 117–145

    Chapter  Google Scholar 

  • Handley LL, Raven JA (1992) The use of natural abundance of nitrogen isotopes in plant physiology and ecology. Plant Cell Environ 15:965–985. doi:10.1111/j.1365-3040.1992.tb01650.x

    Article  CAS  Google Scholar 

  • Hartnett DC, Potgieter AF, Wilson GWT (2004) Fire effects on mycorrhizal symbiosis and root system architecture in southern African savanna grasses. Afr J Ecol 42:328–337. doi:10.1111/j.1365-2028.2004.00533.x

    Article  Google Scholar 

  • Hawkins H-J, Hettasch H, West AG, Cramer MD (2009) Hydraulic redistribution by Protea “Sylvia” (Proteaceae) facilitates soil water replenishment and water acquisition by an understorey grass and shrub. Funct Plant Biol 36:752–760. doi:10.1071/FP09046

    Article  Google Scholar 

  • Hesla BI, Tieszen HL, Boutton TW (1985) Seasonal water relations of savanna shrubs and grasses in Kenya, East Africa. J Arid Environ 8:15–31

    Google Scholar 

  • Hobbie EA, Macko SA, Shugart HH (1999) Interpretation of nitrogen isotope signatures using the NIFTE model. Oecologia 120:405–415. doi:10.1007/s004420050873

    Article  Google Scholar 

  • Hogberg P (1990) 15N natural abundance as a possible marker of the ectomycorrhizal habit of trees in mixed African woodlands. New Phytol 115:483–486. doi:10.1111/j.1469-8137.1990.tb00474.x

    Article  Google Scholar 

  • Hogberg P (1997) 15N natural abundance in soil-plant systems. New Phytol 137:179–203

    Article  Google Scholar 

  • Hogberg P, Alexander IJ (1995) Roles of root symbioses in African woodland and forest: evidence from 15N abundance and foliar analysis. J Ecol 83:217–224

    Article  Google Scholar 

  • Hogberg P, Piearce GD (1986) Mycorrhizas in Zambian trees in relation to host taxonomy, vegetation type and successional patterns. J Ecol 74:775–785

    Article  Google Scholar 

  • Jacobs SM, Pettit NE, Naiman RJ (2007) Nitrogen fixation by the savanna tree Philenoptera violacea (Klotzsch) Schrire (apple leaf) of different ages in a semi-arid riparian landscape. S Afr J Bot 73:163–167. doi:10.1016/j.sajb.2006.09.001

    Article  CAS  Google Scholar 

  • Knoop WT, Walker BH (1985) Interactions of woody and herbaceous vegetation in a southern African savanna. J Ecol 73:235–253

    Article  Google Scholar 

  • Kulmatiski A, Beard KH, Verweij RJT, February EC (2010) A depth-controlled tracer technique measures vertical, horizontal and temporal patterns of water use by trees and grasses in a subtropical savanna. New Phytol 188:199–209. doi:10.1111/j.1469-8137.2010.03338.x

    Article  PubMed  Google Scholar 

  • Lehmann J, Muraoka T, Zech W (2001) Root activity patterns in an Amazonian agroforest with fruit trees determined by 32P, 33P and 15N applications. Agrofor Syst 52:185–197

    Article  Google Scholar 

  • Littell RC, Milliken GA, Stroup WW, Wolfinger RD, Schabenberger O (2006) SAS for mixed models. SAS Institute, Cary

    Google Scholar 

  • Ludwig F, Dawson TE, Prins HHT, Berendse F, Kroon H (2004) Below-ground competition between trees and grasses may overwhelm the facilitative effects of hydraulic lift. Ecol Lett 7:623–631. doi:10.1111/j.1461-0248.2004.00615.x

    Article  Google Scholar 

  • Masclaux-Daubresse C, Daniel-Vedele F, Dechorgnat J, Chardon F, Gaufichon L, Suzuki A (2010) Nitrogen uptake, assimilation and remobilization in plants: challenges for sustainable and productive agriculture. Ann Bot 105:1141–1157. doi:10.1093/aob/mcq028

    Article  PubMed Central  PubMed  Google Scholar 

  • McKane RB, Johnson LC, Shaver GR, Nadelhoffer KJ, Rastetter EB, Fry B, Giblin AE, Kielland K, Kwiatkowski BL, Laundre JA, Murray G (2002) Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra. Nature 415:68–71. doi:10.1038/415068a

    Article  CAS  PubMed  Google Scholar 

  • Millard P, Grelet G-A (2010) Nitrogen storage and remobilization by trees: ecophysiological relevance in a changing world. Tree Physiol 30:1083–1095. doi:10.1093/treephys/tpq042

    Article  CAS  PubMed  Google Scholar 

  • Nadelhoffer KJ, Fry B (1994) Nitrogen isotope studies in forest ecosystems. In: Lajtha K, Michener RH (eds) Stable isotopes in ecology and environmental science. Blackwell Science, Oxford, pp 22–44

    Google Scholar 

  • Robinson D (2001) δ15N as an integrator of the nitrogen cycle. Trends Ecol Evol 16:153–162. doi:10.1016/S0169-5347(00)02098-X

    Article  PubMed  Google Scholar 

  • Sala OE, Golluscio RA, Lauenroth WK, Soriano A (1989) Resource partitioning between shrubs and grasses in the Patagonian steppe. Oecologia 81:501–505. doi:10.1007/BF00378959

    Article  Google Scholar 

  • Sankaran M, Hanan NP, Scholes RJ, Ratnam J, Augustine DJ, Cade BS, Gignoux J, Higgins SI, Le Roux X, Ludwig F, Ardo J, Banyikwa F, Bronn A, Bucini G, Caylor KK, Coughenour MB, Diouf A, Ekaya W, Feral CJ, February EC, Frost PGH, Hiernaux P, Hrabar H, Metzger KL, Prins HHT, Ringrose S, Sea W, Tews J, Worden J, Zambatis N (2005) Determinants of woody cover in African savannas. Nature 438:846–849. doi:10.1038/nature04070

    Article  CAS  PubMed  Google Scholar 

  • Schoener TW (1974) Resource partitioning in ecological communities. Science 185(4145):27–39

    Article  CAS  PubMed  Google Scholar 

  • Scholes MC, Scholes RJ, Otter LB, Woghiren AJ (2003) Biogeochemisty: the cycling of elements. In: Du Toit JT, Rogers KH, Biggs HC (eds) The Kruger experience: ecology and management of savanna heterogeneity. Island Press, Washington, pp 130–148

    Google Scholar 

  • Shearer G, Kohl DH (1986) N2-fixation in field settings : estimations based on natural 15N abundance. Aust J Plant Physiol 13:699–756

    CAS  Google Scholar 

  • Sternberg LDSL, Bucci S, Franco A, Goldstein G, Hoffman WA, Meinzer FC, Moreira MZ, Scholz F (2005) Long range lateral root activity by Neotropical savanna trees. Plant Soil 270:169–178. doi:10.1007/s11104-004-1334-9

    Article  CAS  Google Scholar 

  • Stroosnijder L (1991) The soils of Sahel and the experimental fields. In: De Vries FWTP, Mjiteye MA (eds) The productivity of Sahelian rangelands, a study of soils, vegetation and exploitation of this natural resource. Wageningen University, Wageningen, pp 52–71

    Google Scholar 

  • Swap RJ, Aranibar JN, Dowty PR, Gilhooly WP III, Macko SA (2004) Natural abundance of 13C and 15N in C3 and C4 vegetation of southern Africa: patterns and implications. Glob Chang Biol 10:350–358. doi:10.1046/j.1529-8817.2003.00702.x

    Article  Google Scholar 

  • Tagliavini M, Millard P (2005) Fluxes of nitrogen within deciduous fruit trees. Acta Sci Pol Hort Cult 4:21–30

    Google Scholar 

  • Vitousek PM, Shearer G, Kohl DH (1989) Foliar 15N natural abundance in Hawaiian rainforest: patterns and possible mechanism. Oecologia 78:383–388

    Article  Google Scholar 

  • Walter H (1971) Ecology of tropical and subtropical vegetation. Oliver and Boyd, Edinburgh

    Google Scholar 

  • Wang L, Macko SA (2011) Constrained preferences in nitrogen uptake across plant species and environments. Plant Cell Environ 34:525–534. doi:10.1111/j.1365-3040.2010.02260.x

    Article  CAS  PubMed  Google Scholar 

  • Zencich SJ, Froend RH, Turner JV, Gailitis V (2002) Influence of groundwater depth on the seasonal sources of water accessed by Banksia tree species on a shallow, sandy coastal aquifer. Oecologia 131:8–19. doi:10.1007/s00442-001-0855-7

    Article  Google Scholar 

Download references

Acknowledgments

This research was supported by Shell Research Foundation and the Resource Ecology Group at Wageningen University. The Mpumalanga Tourism and Parks Agency kindly granted us permission to carry out this study at the AGR and we thank the management and staff of AGR for their cooperation. The management and staff of Wits Rural Facility of the University of Witwatersrand are thanked for providing work space and assistance in the field. We thank Phanuel Manzini and Floyd Manzini for their assistance in the field and laboratory in South Africa. Grant Hall is thanked for his help in the stable isotope laboratory. K. Yoganand helped in fieldwork and provided comments on earlier versions of the manuscript.

Author information

Authors and Affiliations

  1. Resource Ecology Group, Wageningen University, Wageningen, The Netherlands

    K. V. R. Priyadarshini, Herbert H. T. Prins, Steven de Bie & Ignas M. A. Heitkönig

  2. iThemba Laboratories, WITS, Private Bag 11, Johannesburg, 2050, South Africa

    Stephan Woodborne

  3. Biometris, Wageningen University, Wageningen, The Netherlands

    Gerrit Gort

  4. University of KwaZulu-Natal, Scottsville, Pietermaritzburg, 3209, South Africa

    Kevin Kirkman

  5. Australian Rivers Institute, Griffith University, Brisbane, QLD, 4111, Australia

    Brian Fry

  6. Department of Experimental Plant Ecology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands

    Hans de Kroon

Authors
  1. K. V. R. Priyadarshini
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Herbert H. T. Prins
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Steven de Bie
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Ignas M. A. Heitkönig
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Stephan Woodborne
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Gerrit Gort
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Kevin Kirkman
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Brian Fry
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Hans de Kroon
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to K. V. R. Priyadarshini.

Additional information

Communicated by Allan Green.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (DOCX 30 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Priyadarshini, K.V.R., Prins, H.H.T., de Bie, S. et al. Overlap in nitrogen sources and redistribution of nitrogen between trees and grasses in a semi-arid savanna. Oecologia 174, 1107–1116 (2014). https://doi.org/10.1007/s00442-013-2848-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00442-013-2848-8

Keywords

Search

Navigation