Skip to main content

Advertisement

SpringerLink
Log in

Effects of Alien Plants on Ecosystem Structure and Functioning and Implications for Restoration: Insights from Three Degraded Sites in South African Fynbos

  • Published:
Environmental Management Aims and scope Submit manuscript

Abstract

We investigated the type and extent of degradation at three sites on the Agulhas Plain, South Africa: an old field dominated by the alien grass Pennisetum clandestinum Pers. (kikuyu), an abandoned Eucalyptus plantation, and a natural fynbos community invaded by nitrogen fixing—Australian Acacia species. These forms of degradation are representative of many areas in the region. By identifying the nature and degree of ecosystem degradation we aimed to determine appropriate strategies for restoration in this biodiversity hotspot. Vegetation surveys were conducted at degraded sites and carefully selected reference sites. Soil-stored propagule seed banks and macro- and micro-soil nutrients were determined. Species richness, diversity and native cover under Eucalyptus were extremely low compared to the reference site and alterations of the soil nutrients were the most severe. The cover of indigenous species under Acacia did not differ significantly from that in reference sites, but species richness was lower under Acacia and soils were considerably enriched. Native species richness was much lower in the kikuyu site, but soil nutrient status was similar to the reference site. Removal of the alien species alone may be sufficient to re-initiate ecosystem recovery at the kikuyu site, whereas active restoration is required to restore functioning ecosystems dominated by native species in the Acacia thicket and the Eucalyptus plantation. To restore native plant communities we suggest burning, mulching with sawdust and sowing of native species.

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
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

References

  • Adams MA, Attiwill PM (1986) Nutrient cycling and nitrogen mineralization in eucalypt forests of south-eastern Australia. 1. Nutrient cycling and nitrogen turnover. Plant and Soil 92:319–339

    Article  CAS  Google Scholar 

  • Alcorn PJ, Bauhus J, Thomas DS, James RN, Smith RGB, Nicotra AB (2008) Photosynthetic response to green crown pruning in young plantation-grown Eucalyptus pilularis and E. cloeziana. Forest Ecology and Management 255:3827–3838

    Article  Google Scholar 

  • Bargali SS, Singh RP, Joshi M (1993) Changes in soil characteristics in eucalypt plantations replacing natural broad-leaved forests. Journal of Vegetation Science 4:25–28

    Article  Google Scholar 

  • Bernhard-Reversat F (1996) Nitrogen cycling in tree plantations grown on a poor sandy savanna soil in Congo. Applied Soil Ecology 4:161–172

    Article  Google Scholar 

  • Binkley D, Dunkin KA, Debell D, Ryan MG (1992) Production and nutrient cycling in mixed plantations of Eucalyptus and Albizia in Hawaii. Forest Science 38:393–408

    Google Scholar 

  • Briones MJI, Ineson P (1996) Decomposition of Eucalyptus leaves in litter mixtures. Soil Biology & Biochemistry 28:1381–1388

    Article  CAS  Google Scholar 

  • Brooks ML, D’Antonio CM, Richardson DM, Grace JB, Keeley JE, DiTomaso JM, Hobbs RJ, Pellant M, Pyke D (2004) Effects of invasive alien plants on fire regimes. Bioscience 54:677–688

    Article  Google Scholar 

  • Brown NAC, Botha PA (2004) Smoke seed germination studies and a guide to seed propagation of plants from the major families of the Cape Floristic Region, South Africa. South African Journal of Botany 70:559–581

    Google Scholar 

  • Brudvig LA (2011) The restoration of biodiversity: where has research been und where does it need to go? American Journal of Botany 98:1–10

    Google Scholar 

  • Chabrerie O, Loinard J, Perrin S, Saguez R, Decocq G (2010) Impact of Prunus serotina invasion on understory functional diversity in a European temperate forest. Biological Invasions 12:1891–1907

    Article  Google Scholar 

  • Cione NK, Padgett PE, Allen EB (2002) Restoration of a native shrubland impacted by exotic grasses, frequent fire, and nitrogen deposition in southern California. Restoration Ecology 10:376–384

    Article  Google Scholar 

  • Clarke KR, Warwick RM (2001) Change in marine communities: an approach to statistical analysis and interpretation. PRIMER-E Ltd, Plymouth

    Google Scholar 

  • Cleveland RB, Cleveland WS, McRae JE, Terpenning I (1990) A seasonal-trend decomposition procedure based on Loess. Journal of Official Statistics 6:3–73

    Google Scholar 

  • Corbin JD, D’Antonio CM (2004) Effects of exotic species on soil nitrogen cycling: implications for restoration. Weed Technology 18:1464–1467

    Article  CAS  Google Scholar 

  • Cowling RM, Gxaba T (1990) Effects of a fynbos overstorey shrub on understorey community structure: implications for the maintenance of community wide species richness. South African Journal of Ecology 1:1–7

    Google Scholar 

  • Cudney DW, Downer JA, Gibeault VA, Henry JM, Reints JS (1993) Kikuyugrass (Pennisetum clandestinum) management in turf. Weed Technology 7:180–184

    CAS  Google Scholar 

  • Del Moral R, Muller CH (1970) The allelopathic effects of Eucalyptus camaldulensis. American Midland Naturalist 83:254–282

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  • Fernandez-Delgado C (1997) Conservation management of a European natural area: Donana National Park, Spain. In: Meffe GK, Carroll CR (eds) Principles of conservation biology. Sinauer Associates Inc, Sunderland, Massachusetts, pp 458–467

    Google Scholar 

  • Forsyth GG, Richardson DM, Brown PJ, van Wilgen BW (2004) A rapid assessment of the invasive status of Eucalyptus species in two South African provinces. South African Journal of Science 100:75–77

    Google Scholar 

  • Gaertner M, Den Breeyen A, Hui C, Richardson DM (2009) Impacts of alien plant invasions on species richness in Mediterranean-type ecosystems: A meta-analysis. Progress in Physical Geography 33:319–338

    Article  Google Scholar 

  • Gaertner M, Holmes PM, Richardson DM (2011) Biological invasions, resilience and restoration. In: Van Andel J, Aronson J (eds) Restoration Ecology: the New Frontier. Blackwell Publishing LTD, Oxford, England

  • Gibson DJ (1986) Spatial and temporal heterogeneity in soil nutrient supply measured using in situ ion-exchange resin bags. Plant and Soil 96:445–450

    Article  CAS  Google Scholar 

  • Gioria M, Osborne B (2009) Assessing the impact of plant invasions on soil seed bank communities: use of univariate and multivariate statistical approaches. Journal of Vegetation Science 20:547–556

    Article  Google Scholar 

  • Goldblatt P, Manning J (2000) Cape plants. A conspectus of the Cape flora of South Africa. Strelitzia 9:1–744

    Google Scholar 

  • Graciano C, Goya JF, Arturi M, Perez C, Frangi JL (2008) Fertilization in a fourth rotation Eucalyptus grandis plantation with minimal management. Journal of Sustainable Forestry 26:155–169

    Article  Google Scholar 

  • Guo LB, Sims REH (2001) Effects of light, temperature, water and meat works effluent irrigation on eucalypt leaf litter decomposition under controlled environmental conditions. Applied Soil Ecology 17:229–237

    Article  Google Scholar 

  • Gurevitch J, Padilla DK (2004) Are invasive species a major cause of extinctions? Trends in Ecology & Evolution 19:470–474

    Article  Google Scholar 

  • Hejda M, Pyšek P, Jarosik V (2009) Impact of invasive plants on the species richness, diversity and composition of invaded communities. Journal of Ecology 97:393–403

    Article  Google Scholar 

  • Hellmann C, Sutter R, Rascher KG, Máguas C, Correia O, Werner C (2011) Impact of an exotic N2-fixing Acacia on composition and N status of a native Mediterranean community. Acta Oecologica 37:43–50

    Article  Google Scholar 

  • Herr C, Chapuis-Lardy L, Dassonville N, Vanderhoeven S, Meerts P (2007) Seasonal effect of the exotic invasive plant Solidago gigantea on soil pH and P fractions. Journal of Plant Nutrition and Soil Science-Zeitschrift für Pflanzenernährung und Bodenkunde 170:729–738

    Article  CAS  Google Scholar 

  • Hobbs RJ (2007) Setting effective and realistic restoration goals: Key directions for research. Restoration Ecology 15:354–357

    Google Scholar 

  • Holmes PM (2002) Depth distribution and composition of seed-banks in alien-invaded and uninvaded fynbos vegetation. Austral Ecology 27:110–120

    Article  Google Scholar 

  • Holmes PM (2008) Optimal ground preparation treatments for restoring lowland Sand Fynbos vegetation on old fields. South African Journal of Botany 74:33–40

    Article  Google Scholar 

  • Holmes PM, Cowling RM (1997) The effects of invasion by Acacia saligna on the guild structure and regeneration capabilities of South African fynbos shrublands. Journal of Applied Ecology 34:317–332

    Article  Google Scholar 

  • Holmes PM, Richardson DM (1999) Protocols for the restoration based on recruitment dynamics, community structure and ecosystem function: perspectives from South African fynbos. Restoration Ecology 7:215–230

    Article  Google Scholar 

  • Joubert L, Esler KJ, Privett SDJ (2009) The effect of ploughing and augmenting natural vegetation with commercial fynbos species on the biodiversity of Overberg Sandstone fynbos on the Agulhas Plain, South Africa. South African Journal of Botany 75:526–531

    Article  Google Scholar 

  • Lajtha K (1988) The use of ion-exchange resin bags for measuring nutrient availability in an arid ecosystem. Plant and Soil 105:105–111

    Article  CAS  Google Scholar 

  • Le Maitre DC, van Wilgen BW, Gelderblom CM, Bailey C, Chapman RA, Nel JA (2002) Invasive alien trees and water resources in South Africa: case studies of the costs and benefits of management. Forest Ecology and Management 160:143–159

    Article  Google Scholar 

  • MacDougall SA, Turkington R (2005) Are invasive species the drivers or passengers of change in degraded ecosystems? Ecology 86:42–55

    Article  Google Scholar 

  • Marchante HS, Marchante EM, Buscardo E, Maia J, Freitas H (2004) Recovery potential of dune ecosystems invaded by an exotic Acacia species (Acacia longifolia). Weed Technology 18:1427–1433

    Article  Google Scholar 

  • Marchante E, Kjøller A, Struwe S, Freitas H (2007) Soil microbial activity in dune ecosystems in Portugal invaded by Acacia longifolia. In: Tokarska-Guzik B, Brock JH, Brundu G, Child L, Daehler CC, Pysek P (eds) Plant invasions: human perception, ecological impacts and management. Backhuys Publishers, Leiden, The Netherlands, pp 247–257

    Google Scholar 

  • Marchante E, Kjoller A, Struwe S, Freitas H (2008) Short- and long-term impacts of Acacia longifolia invasion on the belowground processes of a Mediterranean coastal dune ecosystem. Applied Soil Ecology 40:210–217

    Article  Google Scholar 

  • Maron JL, Jefferies RL (1999) Bush lupine mortality, altered resource availability, and alternative vegetation states. Ecology 80:443–454

    Article  Google Scholar 

  • Maron JL, Jeffries RL (2001) Restoring enriched grasslands: effects of mowing on species richness, productivity, and nitrogen retention. Ecological Applications 11:1088–1100

    Article  Google Scholar 

  • May EF, Ash JE (1990) An assessment of the allelopathic potential of Eucalyptus. Australian Journal of Botany 38:245–254

    Article  Google Scholar 

  • Meiners SJ, Pickett STA, Cadenasso ML (2002) Exotic plant invasions over 40 Years of old field successions: community patterns and associations. Ecography 25:215–223

    Google Scholar 

  • Milton SJ (1981) Litterfall of the exotic acacias in the south-western Cape South African Journal of Botany 47:147–155

    Google Scholar 

  • Milton SJ (2004) Grasses as invasive alien plants in South Africa. South African Journal of Science 100:69–75

    Google Scholar 

  • Mitchell DT, Coley PGF (1987) Litter production and decomposition from shrubs of Protea repens growing on sand-plain lowland and mountain fynbos, south-western Cape. South African Journal of Botany 53:25–31

    Google Scholar 

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

  • Musil CF (1993) Effect of invasive Australian Acacias on the regeneration, growth and nutrient chemistry of South-African lowland fynbos. Journal of Applied Ecology 30:361–372

    Article  Google Scholar 

  • Musil CF, Midgley GF (1990) The relative impact of invasive Australian acacias, fire and season on the soil chemical status of a sand plain lowland fynbos community. South African Journal of Botany 56:419–427

    Google Scholar 

  • Nakos G (1977) Acetylene-reduction (N2-Fixation) by Nodules of Acacia cyanophylla. Soil Biology & Biochemistry 9:131–133

    Article  CAS  Google Scholar 

  • Ndaw SM, Gama-Rodrigues AC, Gama-Rodrigues EF, Sales KRN, Rosado AS (2009) Relationships between bacterial diversity, microbial biomass, and litter quality in soils under different plant covers in northern Rio de Janeiro State, Brazil. Canadian Journal of Microbiology 55:1089–1095

    Article  CAS  Google Scholar 

  • Peperkorn R, Werner C, Beyschlag W (2005) Phenotypic plasticity of an invasive acacia versus two native Mediterranean species. Functional Plant Biology 32:933–944

    Article  Google Scholar 

  • Plieninger T, Gaertner M (2011) Harnessing degraded lands for biodiversity conservation. Journal for Nature Conservation 19:18–23

    Article  Google Scholar 

  • Posada JM, Aide TM, Cavelier J (2000) Cattle and weedy shrubs as restoration tools of tropical montane rainforest. Restoration Ecology 8:370–379

    Article  Google Scholar 

  • Privett SDJ, Heydenrych BJ, Cowling RM (2002) Putting biodiversity to business on the Agulhas Plain. In: Pierce SM, Cowling RM, Sandwith T, MacKinnon K (eds) Mainstreaming biodiversity in development. Case studies from South Africa. World Bank, Washington DC, pp 101–116

    Google Scholar 

  • Rebelo AG (1992) Preservation of biotic diversity. In: Cowling RM (ed) The ecology of fynbos: nutrients, fire and diversity. Oxford University Press, Cape Town, pp 309–344

    Google Scholar 

  • Richardson DM (1998) Forestry trees as invasive aliens. Conservation Biology 12:18–26

    Article  Google Scholar 

  • Richardson DM, Holmes PM, Esler KJ, Galatowitsch SM, Stromberg JC, Kirkman SP, Pyšek P, Hobbs RJ (2007) Riparian vegetation: degradation, alien plant invasions, and restoration prospects. Diversity and Distributions 13:126–139

    Article  Google Scholar 

  • Rouget M, Richardson DM, Cowling RM, Lloyd JW, Lombard AT (2003) Current patterns of habitat transformation and future threats to biodiversity in terrestrial ecosystems of the Cape Floristic Region, South Africa. Biological Conservation 112:63–85

    Article  Google Scholar 

  • Ruthrof KX, Loneragan WA, Yates CJ (2003) Comparative population dynamics of Eucalyptus cladocalyx in its native habitat and as an invasive species in an urban bushland in south-western Australia. Diversity and Distributions 9:469–483

    Article  Google Scholar 

  • Seabloom EW, Borer ET, Boucher VL, Burton RS, Cottingham KL, Goldwasser L, Gram WK, Kendall BE, Micheli F (2003) Competition, seed limitation, disturbance, and reestablishment of California native annual forbs. Ecological Applications 13:575–592

    Article  Google Scholar 

  • Seabloom EW, Williams JW, Slayback D, Stoms DM, Viers JH, Dobson AP (2006) Human impacts, plant invasion, and imperiled, plant species in California. Ecological Applications 16:1338–1350

    Article  Google Scholar 

  • Souto XC, Gonzalez L, Reigosa MJ (1994) Comparative analysis of allelopathic effects produced by 4 forestry species during decomposition process in their soils in Galicia (NW Spain). Journal of Chemical Ecology 20:3005–3015

    Article  CAS  Google Scholar 

  • Stock WD, Lewis OAM (1986) Atmospheric input of nitrogen to a coastal fynbos ecosystem of the south-western Cape Province, South Africa. South African Journal of Botany 52:273–276

    CAS  Google Scholar 

  • Turner J, Lambert MJ (2008) Nutrient cycling in age sequences of two Eucalyptus plantation species. Forest Ecology and Management 255:1701–1712

    Article  Google Scholar 

  • Turner PJ, Scott JK, Spafford H (2008) The ecological barriers to the recovery of bridal creeper (Asparagus asparagoides (L.) Druce) infested sites: impacts on vegetation and the potential increase in other exotic species. Austral Ecology 33:713–722

    Article  Google Scholar 

  • Tyynela TM (2001) Species diversity in Eucalyptus camaldulensis woodlots and miombo woodland in Northeastern Zimbabwe. New Forests 22:239–257

    Article  Google Scholar 

  • Underwood EC, Viers JH, Klausmeyer KR, Cox RL, Shaw MR (2009) Threats and biodiversity in the mediterranean biome. Diversity and Distributions 15:188–197

    Article  Google Scholar 

  • van Wilgen BW, Richardson DM, Seydack A (1994) Managing fynbos for biodiversity: constraints and options in a fire-prone environment. South African Journal of Science 90:322–329

    Google Scholar 

  • Viana SM, David VA, Fushita AT, Garcia C, Oliveira FF, Nakajo JC, Santos LRB, Batalha MA (2003) Diversity of the cerrado woody component in regeneration process under influence of Eucalyptus in Sao Carlos, Sao Paulo, Brazil. Arquivos do Instituto Biologico (Sao Paulo) 70:76

    Google Scholar 

  • Vilà M, Gimeno I (2007) Does invasion by an alien plant species affect the soil seed bank? Journal of Vegetation Science 18:423–430

    Article  Google Scholar 

  • Vinton MA, Goergen EM (2006) Plant-soil feedbacks contribute to the persistence of Bromus inermis in tallgrass prairie. Ecosystems 9:967–976

    Article  CAS  Google Scholar 

  • Walsh PG, Barton CVM, Haywood A (2008) Growth and carbon sequestration rates at age ten years of some Eucalypt species in the low- to medium-rainfall areas of New South Wales, Australia. Australian Forestry 71:70–77

    Google Scholar 

  • Wearne LJ, Morgan JW (2006) Shrub invasion into subalpine vegetation: implications for restoration of the native ecosystem. Plant Ecology 183:361–376

    Article  Google Scholar 

  • Werner C, Zumkier U, Beyschlag W, Maguas C (2010) High competitiveness of a resource demanding invasive acacia under low resource supply. Plant Ecology 206:83–96

    Article  Google Scholar 

  • Williams JA, West CJ (2000) Environmental weeds in Australia and New Zealand: issues and approaches to management. Austral Ecology 25:425–444

    Article  Google Scholar 

  • Witkowski ETF (1991) Effects of invasive alien Acacias on nutrient cycling in the coastal lowlands of the Cape Fynbos. Journal of Applied Ecology 28:1–15

    Article  Google Scholar 

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

    Article  Google Scholar 

  • Yelenik SG, Stock WD, Richardson DM (2007) Functional group identity does not predict invader impacts: differential effects of nitrogen-fixing exotic plants on ecosystem function. Biological Invasions 9:117–125

    Article  Google Scholar 

  • Zink TA, Allen MF (1998) The effects of organic amendments on the restoration of a disturbed coastal sage scrub habitat. Restoration Ecology 6:52–58

    Article  Google Scholar 

Download references

Acknowledgments

We are grateful to Patricia Holmes for very helpful discussions in experiment implementation and for her ongoing support during the project and to Brigitte Braschler and Rainer M. Krug for statistical advice. Financial support was provided by the Flower Valley Conservation Trust and the Agulhas Biodiversity initiative. We acknowledge support from the DST-NRF Centre of Excellence for Invasion Biology (MG, DMR) and the Hans Sigrist Foundation (DMR).

Author information

Authors and Affiliations

  1. Centre for Invasion Biology, Department of Botany & Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa

    Mirijam Gaertner & David M. Richardson

  2. Flower Valley Conservation Trust, PO Box 393, Gansbaai, 7220, South Africa

    Sean D. J. Privett

Authors
  1. Mirijam Gaertner
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. David M. Richardson
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Sean D. J. Privett
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Mirijam Gaertner.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gaertner, M., Richardson, D.M. & Privett, S.D.J. Effects of Alien Plants on Ecosystem Structure and Functioning and Implications for Restoration: Insights from Three Degraded Sites in South African Fynbos. Environmental Management 48, 57–69 (2011). https://doi.org/10.1007/s00267-011-9675-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00267-011-9675-7

Keywords

Search

Navigation