Ornamental Plants as Invasive Aliens: Problems and Solutions in Kruger National Park, South Africa
- 1.4k Downloads
The most widespread invasive alien plant species in South Africa’s Kruger National Park (KNP) were either introduced unintentionally along rivers and roads, or intentionally for use as ornamentals. We examine the spatial distribution of ornamental alien plants in KNP, look at the link between human population size, history, and species richness, and show how the distribution of particular species reflects the likely history of ornamental plantings. Results are used to assess whether past management actions have been appropriately directed.
Two hundred and fifty-eight alien species have been recorded in the 36 tourist camps and staff villages. The number of staff housed in villages explains much of the diversity of cultivated alien plant species. Older camps also tend to have more ornamental alien plant species. However, the lack of a strong link between camp age and number of cultivated species suggests that ornamental plants have been widely spread around the KNP by humans. We also show that increased camp activity (either size or age) has led to more ornamental species, while, with the notable exception of Skukuza, camp activity has had a much smaller effect on the number of noncultivated species. Noncultivated species tend to be naturally dispersed, as opposed to directly spread by humans between camps.
Past management prioritized certain species on the basis of their potential to invade KNP and on the prevailing national legislation. These species were removed manually and follow-up control was carried out. Once the priority species were deemed to be under control, less invasive species were targeted. All alien species were removed from vacated houses, regardless of the potential invasiveness of the species.
KeywordsBiological invasions Horticulture Invasive alien plants Human dimensions Management Naturalized plants Ornamental plants Protected areas Weed
We thank Sandra MacFadyen for GIS assistance, Geoff Nichols, Lesley Henderson, and Guin Zambatis for assistance with the species identification and listing, and Michelle Greve for help with the nestedness analysis. We thank SANParks and the DST-NRF Centre of Excellence for Invasion Biology. DMR thanks the Hans Sigrist Foundation, Switzerland, for financial support.
- Baskin Y (2002) A plague of rats and rubbervines: the growing threats of species invasions. Shearwater Books, Washington, D.CGoogle Scholar
- Binggeli P (2001) The human dimensions of invasive woody plants. In: McNeely JA (ed) The great reshuffling: human dimensions of invasive alien species. IUCN, Gland, Switzerland pp 145–160Google Scholar
- du Toit JT., Rogers KH, Biggs HC (eds) (2003) The Kruger experience: ecology and management of savanna heterogeneity. Island Press, Washington, D.CGoogle Scholar
- Ewel JJ, O’Dowd DJ, Bergelson J, Daehler CC, D’Antonio CM, Gómez LD, Gordon DR, Hobbs RJ, Holt A, Hopper KR, Hughes CE, LaHart M, Leakey RRB, Lee WG, Loope LL, Lorence DH, Louda SM, Lugo AE, McEvoy PB, Richardson DM, Vitousek PM (1999) Deliberate introductions of species: Research needs. BioScience 49:619–630CrossRefGoogle Scholar
- Foxcroft LC (2001) A case study of human dimensions in invasion and control of alien plants in the personnel villages of Kruger National Park. In: McNeely JA (ed) The great reshuffling: human dimensions of invasive alien species. IUCN, Gland, Switzerland pp 127–134Google Scholar
- Foxcroft LC, Henderson L, Nichols GR, Martin BW (2003) A revised list of alien plants for the Kruger National Park. Koedoe 46:21–44Google Scholar
- Foxcroft LC, Richardson DM (2003) Managing alien plant invasions in the Kruger National Park, South Africa. In: Child LE, Brock JH, Brundu G, Prach K, Pyšek P, Wade PM, Williamson M (eds) Plant Invasions: Ecological Threats and Management Solutions. Backhuys Publishers, Leiden, The Netherlands pp 385–403Google Scholar
- Freitag-Ronaldson S, Foxcroft LC (2003) Anthropogenic influences at the ecosystem level. In: du Toit JT, Rogers KH, Biggs HC (eds) The Kruger experience: ecology and management of savanna heterogeneity. Island Press, Washington, D.C. pp 391–421Google Scholar
- Heritage GL, Moon BP, Jewitt GP, Large ARG, Rountree M (2001) The February 2000 floods on the Sabie River, South Africa: an examination of their magnitude and frequency. Koedoe 44:37–44Google Scholar
- Joubert SCJ (1986) Master plan for the management of the Kruger National Park. South African National Parks (formerly National Parks Board), Skukuza, South AfricaGoogle Scholar
- Pienaar, U de V (1990) Neem uit die verlede. National Parks Board of South AfricaGoogle Scholar
- Pyšek P, Jarošík V, Kučera T (2002a) Patterns of invasion in temperate nature reserves. Biological Conservation 104:13–24Google Scholar
- Pyšek P, Sádlo J, Mandák B (2002b) Catalogue of alien plants of the Czech Republic. Preslia, Praha 74:97–186Google Scholar
- Pyšek P, Sádlo J, Mandák B, Jarošík V (2002c) Czech alien flora and the historical pattern of its formation: what came first to Central Europe? Oecologia 135:122–130Google Scholar
- R Development Core Team (2004) R: A language and environment for statistical computing, R Foundation for Statistical ComputingGoogle Scholar
- Reichard SH, White P (2001) Horticultural introductions of invasive plant species: a North American perspective. In: McNeely JA (ed) The great reshuffling: human dimensions of invasive alien species. IUCN, Gland, Switzerland pp 161–170Google Scholar
- Rejmánek M, Richardson DM, Higgins SI, Pitcairn MJ, Grotkopp E (2005a) Ecology of invasive plants: State of the art. In: Mooney HA, Mack RM, McNeely JA, Neville L, Schei P, Waage J (eds) Invasive alien species: a new synthesis. Island Press, Washington D.C. pp 104–161Google Scholar
- Rejmánek M, Richardson DM, Pyšek P (2005b) Plant invasions and invasibility of plant communities. In: van der Maarel E (ed) Vegetation Ecology. Blackwell Publishing, Oxford pp 332–355Google Scholar
- Richardson DM, Cambray JA, Chapman RA, Dean WRJ, Griffiths CL, Le Maitre DC, Newton DJ, Winstanley TJ (2003) Vectors and pathways of biological invasions in South Africa - Past, future and present. In: Ruiz G, Carlton J (eds) Invasive Species: Vectors and Management Strategies. Island Press, Washington, D.C. pp 292–349Google Scholar
- Sinclair I, Whyte I (1992) Field guide to the birds of the Kruger National Park. Struik Publishers, Cape Town, South AfricaGoogle Scholar
- Sullivan JJ, Timmins SM, Williams PA (2005) Movement of exotic plants into coastal native forests from gardens in northern New Zealand. New Zealand Journal of Ecology 29:1–10Google Scholar
- Sullivan JJ, Williams PA, Timmins SM (2006) Effects of Pinus radiata plantations on environmental weed invasion into adjacent native forest reserves. Department of Conservation Research and Development Series 239, New Zealand Department of ConservationGoogle Scholar
- Wittenberg R, Cock MJW (eds) (2001) Invasive alien species: A toolkit of best prevention and management practices. CAB International, Wallingford, Oxon, UKGoogle Scholar
- Wittenberg R, Cock MJW (2005) Best practices for the prevention and management of invasive alien species. In: Mooney HA, Mack RN, McNeely JA, Neville LE, Schei PJ, Waage JK (eds) Invasive alien species: a new synthesis. Scientific Committee on Problems of the Environment (SCOPE): 63. Island Press, Washington, D.C. pp 209–232Google Scholar