Skip to main content

Frequent fire affects soil nitrogen and carbon in an African savanna by changing woody cover

Oecologia volume 162, pages 1027–1034 (2010)Cite this article

Abstract

When tropical and sub-tropical ecosystems burn, considerable amounts of N present in the biomass fuel may be released. This ultimately results in a loss of fixed N to the atmosphere. It is often assumed that this volatilization loss of N with frequent fire will result in a reduction of plant-available N and total system N. By changing the amount of woody biomass fire may, however, also have indirect effects on N and C dynamics. Here we consider the effects of 50 years of frequent fire on total soil N and soil organic C (SOC) and total soil N in a mesic savanna in the Kruger National Park, South Africa. We also determine how changes in woody biomass may affect total soil N and SOC. We measured soil and fine root N and C concentrations as well as total soil N and SOC pools in four burning treatments, including fire exclusion, of a long-term fire experiment. Our results show that regardless of soil depth, fire treatment had no significant effect on total soil N and SOC. Our results also show that under trees total soil N and SOC concentrations of the surface soil increase, and pools of N and SOC increase to a depth of 7 cm. However, the extent to which soil N and C dynamics differed under canopies and away from canopies was dependent on fire treatment. Our results show that the effect of fire on soil N and C is mediated both through the indirect effect of changes in woody cover and the direct effects of fire (volatilization losses of nutrients). We suggest that woody thickening in this mesic savanna will have pronounced effects on long-term N and C dynamics.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

43,34 €

Price includes VAT (Finland)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2

References

  • Association of Official Analytical Chemists) International (AOCA) (2006) Official methods of analysis of the AOCA, 18th edn. AOCA International, Gaitherburg

  • Archer S, Boutton TW, Hibbard KA (2001) Trees in grasslands: biogeochemical consequences of woody plant expansion. In: Schulze E-D, Harrison SP, Heimann M, Holland EA, Lloyd JL, Prentice C, Schimel D (eds) Global biogeochemical cycles in the climate system. Academic Press, San Diego, pp 115–130

    Chapter  Google Scholar 

  • Barton JM, Bristow JW, Venter FJ (1986) A summary of the Precambian granitoid rocks of the Kruger National Park. Koedoe 29:39–44

    Google Scholar 

  • Belsky AJ (1994) Influences of trees on savanna productivity: tests of shade, nutrients, and tree-grass competition. Ecology 75:922–934

    Article  Google Scholar 

  • Bernhard-Reversat F (1988) Soil nitrogen mineralization under a Eucalyptus plantation and a natural Acacia forest in Senegal. For Ecol Manage 23:233–244

    Article  Google Scholar 

  • Biggs R, Biggs HC, Dunne TT, Govender N, Potgieter ALF (2003) Experimental burn plot trial in the Kruger National Park: history, experimental design, and suggestions for data analysis. Koedoe 6:1–15

    Google Scholar 

  • Boerner REJ (1982) Fire and nutrient cycling in temperate ecosystems. Bioscience 32:187–192

    Article  Google Scholar 

  • Bond WJ, Keeley JE (2005) Fire as a global ‘herbivore’: the ecology and evolution of flammable ecosystems. Trends Ecol Evol 20:387–394

    Article  PubMed  Google Scholar 

  • Caldwell TG, Johnson DW, Miller WW, Qualls RG (2002) Forest floor carbon and nitrogen losses due to prescription fire. Soil Sci Soc Am J 66:262–267

    CAS  Article  Google Scholar 

  • Chen X, Hutley B, Eamus D (2003) Carbon balance of a tropical savanna of northern Australia. Oecologia 137:405–416

    Article  PubMed  Google Scholar 

  • Chuvieco E, Giglio L, Justice C (2008) Global characterization of fire activity: toward defining fire regimes from Earth observation data. Global Change Biol 14:1488–1502

    Article  Google Scholar 

  • Codron J, Codron D, Lee-Thorp JA, Sponheimer M, Bond WJ, de Ruiter D, Grant R (2005) Taxonomic, anatomical, and spatio-temporal variations in stable carbon and nitrogen isotopic compositions of plants from an African savanna. J Archaeol Sci 32:1757–1772

    Article  Google Scholar 

  • Crutzen PJ, Andreae MO (1990) Biomass burning in the tropics: impact on atmospheric chemistry and biogeochemical cycles. Science 250:1669–1678

    Article  CAS  PubMed  Google Scholar 

  • Dijkstra FA, Wrage K, Hobbie SE, Reich PB (2006) Tree patches show greater N losses but maintain higher soil N availability than grassland patches in a frequently burned oak savanna. Ecosystems 9:441–452

    Article  CAS  Google Scholar 

  • Eckhardt HC, Van Wilgen BW, Biggs H (2000) Trends in woody vegetation cover in the Kruger National Park, South Africa, between 1940 and 1998. Afr J Ecol 38:108–115

    Article  Google Scholar 

  • Escudero A, Garcia B, Gomez JM, Luis E (1985) The nutrient cycling in Quercus rotundifolia and Q. pyrenaica ecosystems (‘dehesas’) of Spain. Acta Oecol 6:73–86

    CAS  Google Scholar 

  • Frost PGH, Robertson HG (1987) The ecological effects of fire in savannas. In: Walker BH (ed) Determinants of tropical savanna. IRL, Orlando, pp 93–140

    Google Scholar 

  • Frost PGH, Menaut JC, Walker B, Medina E, Solbrigo T (1986) Responses of savannas to stress and disturbance. International Union of Biological Sciences (special issue 10), Paris

  • Geesing D, Felker P, Bingham RL (2000) Influence of mesquite (Prosopis glandulosa) on soil nitrogen and carbon development: implications for global carbon sequestration. J Arid Environ 46:157–180

    Article  Google Scholar 

  • Gertenbach WPD (1983) Landscapes of the Kruger National Park. Koedoe 26:9–121

    Google Scholar 

  • Georgiadis NJ (1989) Microhabitat variation in an African savanna: effect of woody cover and herbivores in Kenya. J Trop Ecol 5:93–108

    Article  Google Scholar 

  • Hibbard KA, Archer S, Schimel DS, Valentine DW (2001) Biochemical changes accompanying woody plant encroachment in a subtropical savanna. Ecology 82:1999–2011

    Article  Google Scholar 

  • Higgins SI, Bond WJ, February EC, Bronn A, Euston-Brown DI, Enslin B, Govender N, Rademan L, O’Regan S, Potgieter ALF, Scheiter S, Sowry R, Trollope L, Trollope WSW (2007) Effects of four decades of fire manipulation on woody vegetation structure in savanna. Ecology 88:1119–1125

    Article  PubMed  Google Scholar 

  • Hoffmann WA, Orthen B, Kielse P, Do Nascimento V (2003) Comparative fire ecology of tropical savanna and forest trees. Funct Ecol 17:720–726

    Article  Google Scholar 

  • Hoffmann WA, Orthen B, Franco AC (2004) Constraints to seedling success of savanna and forest trees across the savanna-forest boundary. Oecologia 123:252–260

    Google Scholar 

  • Holt JA, Coventry RJ (1990) Nutrient cycling in Australian savannas. J Biogeogr 17:427–432

    Article  Google Scholar 

  • Hudak AT, Wessman CA, Seastedt TR (2003) Woody overstorey effects on soil carbon and nitrogen pools in South African savanna. Austral Ecol 28:173–181

    Article  Google Scholar 

  • Jackson RB, Banner JL, Jobbágy E, Pockman WT, Wall DH (2002) Ecosystem carbon loss with woody plant invasion of grasslands. Nature 418:623–626

    Article  CAS  PubMed  Google Scholar 

  • Kauffman JB, Cummings DL, Ward DE (1994) Relationships of fire, biomass and nutrient dynamics along a vegetation gradient in the Brazilian cerrado. J Ecol 82:519–531

    Article  Google Scholar 

  • Kauffman JB, Cummings DL, Ward DE, Babbitt R (1995) Fire in Brazilian Amazon: 1. Biomass, nutrient pools and losses in slashed primary forest. Oecologia 104:397–408

    Article  Google Scholar 

  • Kellman M (1979) Soil enrichment of Neotropical savanna trees. J Ecol 67:565–577

    Article  CAS  Google Scholar 

  • Khavaghali VP (2008) Forest colonilization of savannas: patterns and processes. MSc thesis, University of Cape Town, South Africa

  • Lal CB, Annapurna C, Raghubanshi AS, Singh JS (2001) Effect of leaf habit and soil type on nutrient resorption and conservation in woody species of a dry tropical environment. Can J Bot 79:1066–1075

    Article  CAS  Google Scholar 

  • Lepage M, Abbadie L, Mariotti A (1993) Food habits of sympatric termite species (Isoptera, macrotermitinae) as determined by stable carbon isotope analysis in a Guinean savanna (Lamto, Côte d’Ivoire). J Trop Ecol 9:303–311

    Article  Google Scholar 

  • McCulley RL, Archer SR, Boutton TW, Hons FM, Zuberer DA (2004) Soil respiration and nutrient cycling in wooded communities developing in grassland. Ecology 85:2804–2817

    Article  Google Scholar 

  • Menaut J-C, Abbadie L, Vitousek PM (1993) Nutrient and organic matter dynamics in tropical ecosystems. In: Crutzen PJ, Goldammer JG (eds) The ecological, atmospheric and climatic importance of vegetation fires. Wiley, New York, pp 215–231

    Google Scholar 

  • Mordelet P, Abbadie L, Menaut J-C (1993) Effects of tree clumps on soil characteristics in a humid savanna of West Africa (Lamto, Côte d’Ivoire). Plant Soil 153:103–111

    Article  Google Scholar 

  • Mordelet P, Menaut J-C, Mariotti A (1997) Tree and grass rooting patterns in African humid savanna. J Veg Sci 8:65–70

    Article  Google Scholar 

  • Mucina L, Rutherford MC (2006) The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria

    Google Scholar 

  • Nelson DW, Sommers LE (1982) Total carbon, organic carbon and organic matter. In: Methods of soil analysis. American Society of Agrononomy. Part 2. Madison, pp 570–571

  • Ojima DS, Schimel DS, Parton WJ, Owensby CE (1994) Long- and short-term effects of fire on nitrogen cycling in tallgrass prairie. Biogeochemistry 24:67–84

    Article  Google Scholar 

  • Ramankutty N, Foley JA (1999) Estimating historical changes in global land cover: croplands from 1700 to 1992. Global Biogeochem Cycles 13:997–1027

    Article  CAS  Google Scholar 

  • Ratnam J, Sankaran M, Hanan N, Grant R, Zambatis N (2008) Nutrient resorption patterns of plant functional groups in a tropical savanna: variation and functional significance. Oecologia 157:141–151

    Article  PubMed  Google Scholar 

  • Reich PB, Peterson DW, Wedin DA, Wrage K (2001) Fire and vegetation effects on productivity and nitrogen cycling across a forest-grassland continuum. Ecology 82:1703–1719

    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, Banyika 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

    Article  CAS  PubMed  Google Scholar 

  • Sankaran M, Ratman J, Hanan NP (2008) Woody cover in African savannas: the role of resources, fire and herbivory. Global Ecol Biogeogr 17:236–245

    Article  Google Scholar 

  • Schlesinger WH, Huenneke LF, Jarrell WM, Virginia RA, Whitford WG (1990) Biological feedbacks in global desertification. Science 247:1043–1048

    Article  PubMed  CAS  Google Scholar 

  • Scholes RJ, Archer SR (1997) Tree-grass interactions in savannas. Annu Rev Ecol Syst 28:517–544

    Article  Google Scholar 

  • Scholes RJ, Hall DO (1996) The carbon budget of tropical savannas, woodlands, and grasslands. In: Breymeyer A, Hall D, Melillo J, Agren G (eds) Modelling terrestrial ecosystems. Wiley, Chichester, pp 69–100

    Google Scholar 

  • Scholes RJ, Walker BH (1993) An African savanna. Synthesis of the Nylsvley study. Cambridge University Press, Cambridge

    Book  Google Scholar 

  • Scholes RJ, Ward DE, Justice CO (1996) Emissions of trace gases and aerosols particles due to vegetation burning in the southern hemisphere Africa. J Geophys Res 101:23677–23677

    Article  CAS  Google Scholar 

  • Scholes MC, Scholes RJ, Otter LB, Woghiren AJ (2003) Biogeochemistry: 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 

  • Soil Analysis Work Committee (Non-affiliated) (1990) Handbook of standard soil testing methods for advisory purposes. Soil Science Society of South Africa, Pretoria

    Google Scholar 

  • Treydte AC, Heitkönig IMA, Prins HHT, Fulco L (2007) Trees improve grass quality for herbivores in African savannas. Perspect Plant Ecol 8:197–205

    Article  Google Scholar 

  • Trollope WSW (1984) Fire in savanna. In: Booysen PDV, Tainton NM (eds) Ecological effects of fire in South African ecosystems. Springer, Berlin

    Google Scholar 

  • Van Wilgen BW, Trollope WSW, Biggs HC, Potgieter ALF, Brockett BH (2003) Fire as a driver of ecosystem variability. In: du Toit JT, Rogers KH, Biggs HC (eds) The Kruger Experience. Ecology and management of savanna heterogeneity. Island Press, Washington, pp 149–170

    Google Scholar 

  • Venter FJ, Scholes RJ, Holger HC (2003) The abiotic template and its associated vegetation pattern. In: du Toit JT, Rogers KH, Biggs HC (eds) The Kruger experience. Ecology and management of savanna heterogeneity. Island, Washington, pp 83–129

    Google Scholar 

  • Walkley A (1935) An examination of methods for determining organic carbon and nitrogen in soils. J Agric Sci 25:598–609

    Article  CAS  Google Scholar 

  • Wan S, Hui D, Luo Y (2001) Fire effects on nitrogen pools and dynamics in terrestrial ecosystems: a meta-analysis. Ecol Appl 11:1349–1349

    Article  Google Scholar 

  • Wang L, D’Odorico P, Manzoni S, Porporato A, Macko S (2009) Soil carbon and nitrogen dynamics in southern African savannas: the effect of vegetation-induced patch-scale heterogeneities and large scale rainfall gradients. Clim Change 94:63–76

    Article  CAS  Google Scholar 

  • Williams RJ, Hutley LB, Cook GD, Russell-Smith J, Edwards A, Chen X (2004) Assessing the carbon sequestration potential of mesic savannas in the Northern Territory, Australia: approaches, uncertainties and impacts of fire. Funct Plant Biol 31:415–422

    Article  CAS  Google Scholar 

Download references

Acknowledgments

The authors extend their thanks to: the Skukuza Scientific Services staff from the South African National Parks (Sanparks) who provided logistical and other support; Annoit Mashele and Ben Wigley for providing valuable help in the field; Joe Craine for constructive comments on an earlier draft of the manuscript. The project was funded with grants from the South African NRF and the Andrew Mellon Foundation. This research was conducted in a manner that complies with current South African laws.

Author information

Affiliations

  1. Department of Botany, University of Cape Town, Rondebosch, 7701, South Africa

    Corli Coetsee, William J. Bond & Edmund C. February

Authors
  1. Corli Coetsee
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. William J. Bond
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Edmund C. February
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Corli Coetsee.

Additional information

Communicated by Nina Buchmann.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Coetsee, C., Bond, W.J. & February, E.C. Frequent fire affects soil nitrogen and carbon in an African savanna by changing woody cover. Oecologia 162, 1027–1034 (2010). https://doi.org/10.1007/s00442-009-1490-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00442-009-1490-y

Keywords

  • Disturbance
  • Fine roots
  • Nitrogen volatilization
  • Tree canopy