Skip to main content
SpringerLink
Log in

An exotic Australian Acacia fixes more N than a coexisting indigenous Acacia in a South African riparian zone

  • Published:
Plant Ecology Aims and scope Submit manuscript

Abstract

Acacia mearnsii is an introduced Australian acacia in South Africa and has invaded more than 2.5 million ha, primarily establishing in rangeland and riparian areas. Because acacias have the capability to fix N, A. mearnsii invasions may fundamentally change N dynamics in invaded systems. This study compares biological N2-fixation in the alien invasive A. mearnsii and the native A. caffra growing in a grassland riparian zone in the Komati Gorge Reserve, Mpumalanga, South Africa. A 15N natural abundance field survey suggested that both mature alien and native acacias fix N under current conditions in the riparian zone. Significantly depleted δ15N was observed in both acacias relative to reference species, although variation in δ15N was not correlated with N concentrations. Calculated contributions of N2-fixation (%Ndfa) suggest that alien acacias fix significantly more of their N than native acacias (~75 ± 5% SE and 53 ± 9% SE, respectively). There was a larger variation in δ15N and %Ndfa in the native acacia, suggesting relatively high plasticity in its N2-fixation contributions. This plasticity was interpreted as a facultative N2-fixation strategy for the native acacia, while the N2-fixation strategy of the alien acacia remained unclear. Our results emphasize the importance of potentially elevated N inputs through N2-fixation by invasive legumes in invaded landscapes. Furthermore, they suggest that N2-fixation by invasive acacias may not respond to fine-scale patchiness in soil N in the same manner as native acacias, making them potential contributors to N excess in Southern Africa.

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

Similar content being viewed by others

References

  • Amundson R, Austin AT, Schuur EAG, Yoo K, Matzek V, Kendall C, Uebersax A, Brenner D, Baisden WT (2003) Global patterns of the isotopic composition of soil and plant nitrogen. Glob Biogeochem Cycl 17(1):1031

    Article  Google Scholar 

  • Boddey R, Peoples M, Palmer B, Dart P (2000) Use of the 15N natural abundance technique to quantify biological nitrogen fixation by woody perennials. Nutr Cycl Agroecosyst 57(3):235–270

    Article  Google Scholar 

  • Boring LR, Swank WT (1984) The role of black locust (Robinia Pseudo-Acacia) in forest succession. J Ecol 72(3):749–766

    Article  Google Scholar 

  • Boring LR, Swank WT, Waide JB, Henderson GS (1988) Sources, fates, and impacts of nitrogen inputs to terrestrial ecosystems: review and synthesis. Biogeochemistry 6(2):119–159

    Article  CAS  Google Scholar 

  • Drake DC (2011) Invasive legumes fix N2 at high rates in riparian areas of an N-saturated, agricultural catchment. J Ecol 99(2):515–523. doi:10.1111/j.1365-2745.2010.01787.x

    Google Scholar 

  • Dye P, Jarmain C (2004) Water use by black wattle (Acacia mearnsii): implications for the link between removal of invading trees and catchment stream flow response. S Afr J Sci 100(1):40–44

    Google Scholar 

  • Ehrenfeld J (2003) Effects of exotic plant invasions on soil nutrient cycling processes. Ecosystems 6(6):503–523

    Article  CAS  Google Scholar 

  • Forrester DI, Schortemeyer M, Stock WD, Bauhus J, Khanna PK, Cowie AL (2007) Assessing nitrogen fixation in mixed- and single-species plantations of Eucalyptus globulus and Acacia mearnsii. Tree Physiol 27(9):1319–1328

    Article  PubMed  CAS  Google Scholar 

  • Högberg P (1997) 15N natural abundance in soil-plant systems. New Phytol 137:179–204

    Google Scholar 

  • Jefferies RL, Maron JL (1997) The embarrassment of riches: atmospheric deposition of nitrogen and community and ecosystem processes. Trends Ecol Evol 12(2):74–78

    Article  PubMed  CAS  Google Scholar 

  • Menge DNL, Levin SA, Hedin LO (2009) Facultative versus obligate nitrogen fixation strategies and their ecosystem consequences. Am Nat 174:465–477

    Article  PubMed  Google Scholar 

  • Moyo HPM, Fatunbi A (2010) Utilitarian perspective of the invasion of some South African biomes by Acacia mearnsii. Glob J Environ Res 4(1):6–17

    Google Scholar 

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

    Google Scholar 

  • Oberholster P, Ashton P (2008) State of the nation report: an overview of the current status of water quality and eutrophication in South African rivers and reservoirs. Parliamentary Grant Deliverable. Council for Scientific and Industrial Research (CSIR), Pretoria

    Google Scholar 

  • Pate JS, Layzell DB (1990) Energetics and biological costs of nitrogen. In: Stumpf PK, Conn EE, Miflin BJ, Lea PJ (eds) The biochemistry of plants, a comprehensive treatise: intermediary nitrogen metabolism assimilation, vol 16. Academic Press, San Diego, pp 1–42

    Google Scholar 

  • Pule-Meulenberg F, Dakora FD (2009) Assessing the symbiotic dependency of grain and tree legumes on N2 fixation for their N nutrition in five agro-ecological zones of Botswana. Symbiosis 48(1):68–77

    Article  CAS  Google Scholar 

  • Rice SK, Westerman B, Federici R (2004) Impacts of the exotic, nitrogen-fixing black locust (Robinia pseudoacacia) on nitrogen-cycling in a pine–oak ecosystem. Plant Ecol 174(1):97–107

    Article  Google Scholar 

  • Schulze ED, Gebauer G, Ziegler H, Lange OL (1991) Estimates of nitrogen fixation by trees on an aridity gradient in Namibia. Oecologia 88(3):451–455

    Article  Google Scholar 

  • Shearer G, Kohl DH (1986) N2-fixation in field settings: estimations based on natural 15N abundance. Aust J Plant Physiol 13(6):699–756

    Google Scholar 

  • Smith VH, Tilman GD, Nekola JC (1999) Eutrophication: impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems. Environ Pollut 100(1–3):179–196

    Article  PubMed  CAS  Google Scholar 

  • StatSoft (2004) STATISTICA (data analysis software system), 6th edn. StatSoft Inc., Tulsa

    Google Scholar 

  • Stock WD, Wienand KT, Baker AC (1995) Impacts of invading N2-fixing Acacia species on patterns of nutrient cycling in two Cape ecosystems: evidence from soil incubation studies and 15N natural abundance values. Oecologia 101(3):375–382

    Article  Google Scholar 

  • Van der Linde GJ, Pitse MA (2006) The South African fertilizer industry. In: Proceedings of the Arab Fertilizer Association conference, Cairo, Egypt, p 9

  • Vitousek PM, Walker LR (1989) Biological invasion by Myrica Faya in Hawai’i: plant demography, nitrogen fixation, ecosystem effects. Ecol Monogr 59(3):247–265

    Article  Google Scholar 

  • Vitousek PM, Aber JD, Howarth RW, Likens GE, Matson PA, Schindler DW, Schlesinger WH, Tilman DG (1997a) Human alteration of the global nitrogen cycle: sources and consequences. Ecol Appl 7(3):737–750

    Google Scholar 

  • Vitousek PM, D’Antonio CM, Loope LL, Rejmanek M, Westbrooks R (1997b) Introduced species: a significant component of human-caused global change. N Z J Ecol 21(1):1–16

    Google Scholar 

  • Vitousek PM, Cassman K, Cleveland C, Crews T, Field CB, Grimm NB, Howarth RW, Marino R, Martinelli L, Rastetter EB, Sprent JI (2002) Towards an ecological understanding of biological nitrogen fixation. Biogeochemistry 57–58(1):1–45. doi:10.1023/a:1015798428743

    Article  Google Scholar 

  • Witkowski ETF (1991) Effects of invasive alien acacias on nutrient cycling in the coastal lowlands of the cape fynbos. J Appl Ecol 28(1):1–15

    Article  Google Scholar 

  • Woghiren AJ (2002) Nitrogen characteristics of the Savanna flux at Skukuza, Kruger National Park. University of the Witwatersrand, Johannesburg

    Google Scholar 

  • Yelenik SG, Stock WD, Richardson DM (2004) Ecosystem level impacts of invasive Acacia saligna in the South African fynbos. Restor Ecol 12(1):44–51

    Article  Google Scholar 

Download references

Acknowledgments

We thank Prof. Bruce Finney of Idaho State University, Gareth Borman for his ideas and advice, and Fanie Baloyi and Andrew O’Rourke for their help in the field. Funding for this study was provided by the University of the Witwatersrand, the University of the Witwatersrand Centre for Water in the Environment, and the Idaho State University Stable Isotope Laboratory.

Author information

Authors and Affiliations

  1. School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, WITS, Johannesburg, 2050, South Africa

    Donovan R. C. Tye & D. C. Drake

Authors
  1. Donovan R. C. Tye
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. D. C. Drake
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to D. C. Drake.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Tye, D.R.C., Drake, D.C. An exotic Australian Acacia fixes more N than a coexisting indigenous Acacia in a South African riparian zone. Plant Ecol 213, 251–257 (2012). https://doi.org/10.1007/s11258-011-9971-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11258-011-9971-6

Keywords

Search

Navigation