Biological Invasions

, Volume 20, Issue 11, pp 3227–3243 | Cite as

The impact of data precision on the effectiveness of alien plant control programmes: a case study from a protected area

  • Chad CheneyEmail author
  • Karen J. Esler
  • Llewellyn C. Foxcroft
  • Nicola J. van Wilgen
  • Melodie A. McGeoch
Original Paper


Successful long-term invasive alien plant control programmes rely on alien plant distribution and abundance data to assess, prioritise, implement and monitor the efficacy of the programme. Here we assess the impact of data accuracy using the alien plant programme in Table Mountain National Park, South Africa. A systematic plot-based survey method was carried out to assess the distribution of alien plants in the park at a fine scale (systematic sampling). Alien plant richness, total area invaded and the degree of spatial overlap in species’ presence were compared between the systematic sample and a protected area (PA) managers’ dataset (collated from collective observations by park visitors, rangers and managers) and Working for Water (WfW) project data (data collected for the planning and implementation of the alien plant clearing programme) using a range of confusion matrix-based statistics to assess similarity and error rates between the datasets. A total of 106 alien plant taxa were detected across the three datasets, 12 in PA manager’s data, 23 in WfW data and 101 in the systematic survey. Overall, there was substantive disagreement between the datasets on the distribution of alien plants. For example both management datasets estimated species’ hectare coverage at orders of magnitude greater than indicated by systematic sampling. The inaccuracy of manager data has direct negative implications for funding allocation, which currently appears to be in excess of what is required. We recommend that contrary to perception, fine-scale surveys are a cost-effective way to inform long-term monitoring programmes and improve programme effectiveness.


Control programme Confusion matrix Invasive species Protected area management Systematic distribution sampling 



Thanks to Leandri Gerber, Khanyisa Tyolo and Richardt Smith who undertook the infield mapping. The following funders and grants are acknowledged: The Table Mountain Fund and the AW Mellon Foundation (CC and infield work), South African National Parks (CC, LCF, NvW), the DST-NRF Centre of Excellence for Invasion Biology (KJE, LCF, NvW), Stellenbosch University (CC, KJE, LCF), the National Research Foundation of South Africa (LCF: Project Numbers IFR2010041400019 and IFR160215158271, KJE: Grant number 103841) and the Australian Research Council (MM: Grant DP150103017). We thank two anonymous reviewers for their constructive comments that helped improve the article.

Supplementary material

10530_2018_1770_MOESM1_ESM.docx (25 kb)
Supplementary material 1 (DOCX 26 kb)
10530_2018_1770_MOESM2_ESM.docx (16 kb)
Supplementary material 2 (DOCX 16 kb)


  1. Alba C, Skálová H, McGregor KF, D’Antonio C, Pyšek P (2015) Native and exotic plant species respond differently to wildfire and prescribed fire as revealed by meta-analysis. J Veg Sci 26:102–113. CrossRefGoogle Scholar
  2. Allouche O, Tsoar A, Kadmon R (2006) Assessing the accuracy of species distribution models: prevalence, kappa and the true skill statistic (TSS). J Appl Ecol 43:1223–1232. CrossRefGoogle Scholar
  3. Alston KP, Richardson DM (2006) The roles of habitat features, disturbance, and distance from putative source populations in structuring alien plant invasions at the urban/wildland interface on the Cape Peninsula, South Africa. Biol Conserv 132:183–198. CrossRefGoogle Scholar
  4. Barr LM, Watson JEM, Possingham HP, Iwamura T, Fuller RA (2016) Progress in improving the protection of species and habitats in Australia. Biol Conserv 200:184–191. CrossRefGoogle Scholar
  5. Biggs HC, Rogers KH (2003) An adaptive system to link science, monitoring and management in practice. In: du Toit JT, Rogers KH, Biggs HC (eds) The Kruger experience: ecology and management of savanna heterogeneity. Island Press, Washington DC, pp 59–80Google Scholar
  6. Brooks ML et al (2004) Effects of invasive alien plants on fire regimes. Bioscience 54:677–688CrossRefGoogle Scholar
  7. Colwell RK (2013) EstimateS: statistical estimation of species richness and shared species from simples, version 9.1. Accessed 13 June 2017
  8. Cook CN, Hockings M, Carter RW (2009) Conservation in the dark? The information used to support management decisions. Front Ecol Environ 8:181–186. CrossRefGoogle Scholar
  9. Cowling RM, MacDonald IAW, Simmons MT (1996) The Cape Peninsula, South Africa: physiographical, biological and historical background to an extraordinary hot-spot of biodiversity. Biodivers Conserv 5:527–550. CrossRefGoogle Scholar
  10. Dewey SA, Andersen KA (2004) Distinct roles of surveys, inventories, and monitoring in adaptive weed management. Weed Technol 18:1449–1452. CrossRefGoogle Scholar
  11. Donlan CJ, Luque GM, Wilcox C (2015) Maximizing return on investment for island restoration and species conservation. Conserv Lett 8:171–179. CrossRefGoogle Scholar
  12. Dudley N, Parish J (2006) Closing the gap. Creating ecologically representative protected area systems: a guide to conducting the gap assessments of protected area systems for the convention on biological diversity. Secretariat of the Convention on Biological Diversity, Montreal, Technical Series no. 24, vi + 108 pagesGoogle Scholar
  13. Ehrenfeld JG (2010) Ecosystem consequences of biological invasions. Annu Rev Ecol Evol Syst 41:59–80. CrossRefGoogle Scholar
  14. ESRI (Environmental Systems Research Institute) (2014) ArcGIS Release 10.1-3. Redlands, CAGoogle Scholar
  15. Fielding A (2007) Cluster and classification techniques for the biosciences, vol 570.15195 F5. Cambridge University Press, CambridgeGoogle Scholar
  16. Fielding AH, Bell JF (1997) A review of methods for the assessment of prediction errors in conservation presence/absence models. Environ Conserv 24:38–49CrossRefGoogle Scholar
  17. Foxcroft LC (2009) Developing thresholds of potential concern for invasive alien species: hypotheses and concepts. Koedoe. CrossRefGoogle Scholar
  18. Foxcroft LC, McGeoch M (2011) Implementing invasive species management in an adaptive management framework. Koedoe. CrossRefGoogle Scholar
  19. Foxcroft LC, Richardson DM, Wilson JR (2008) Ornamental plants as invasive aliens: problems and solutions in Kruger National Park, South Africa. Environ Manag 41:32–51CrossRefGoogle Scholar
  20. Foxcroft LC, Richardson DM, Rouget M, MacFadyen S (2009) Patterns of alien plant distribution at multiple spatial scales in a large national park: implications for ecology, management and monitoring. Divers Distrib 15:367–378. CrossRefGoogle Scholar
  21. Foxcroft LC, Pyšek P, Richardson DM, Pergl J, Hulme PE (2013a) The bottom line: impacts of alien plant invasions in protected areas. In: Foxcroft LC, Pyšek P, Richardson DM, Genovesi P (eds) Plant invasions in protected areas. Springer, Dordrecht, pp 19–41CrossRefGoogle Scholar
  22. Foxcroft LC, Richardson DM, Pyšek P, Genovesi P (2013b) Plant invasions in protected areas: outlining the issues and creating the links. In: Foxcroft LC, Pyšek P, Richardson DM, Genovesi P (eds) Plant invasions in protected areas. Springer, Dordrecht, pp 3–18. CrossRefGoogle Scholar
  23. Foxcroft LC, van Wilgen NJ, Baard JA, Cole NS (2017) Biological invasions in South African National Parks. Bothalia Afr Biodivers Conserv 47:1–12Google Scholar
  24. Gardener MR, Atkinson R, Rentería JL (2010) Eradications and people: lessons from the plant eradication program in Galapagos restoration. Ecology 18:20–29. CrossRefGoogle Scholar
  25. Hauser CE, McCarthy MA (2009) Streamlining ‘search and destroy’: cost-effective surveillance for invasive species management. Ecol Lett 12:683–692CrossRefGoogle Scholar
  26. He FL, Gaston KJ (2000) Occupancy-abundance relationships and sampling scales. Ecography 23:503–511. CrossRefGoogle Scholar
  27. Helme NA, Trinder-Smith TH (2006) The endemic flora of the Cape Peninsula, South Africa. S Afr J Bot 72:205–210. CrossRefGoogle Scholar
  28. Holmes PM, Cowling RM (1997) The effects of invasion by Acacia saligna on the guild structure and regeneration capabilities of South African fynbos shrublands. J Appl Ecol 34:317–332. CrossRefGoogle Scholar
  29. Hulme PE (2006) Beyond control: wider implications for the management of biological invasions. J Appl Ecol 43:835–847. CrossRefGoogle Scholar
  30. Kettenring KM, Adams CR (2011) Lessons learned from invasive plant control experiments: a systematic review and meta-analysis. J Appl Ecol 48:970–979. CrossRefGoogle Scholar
  31. Kotzé I, Beukes H, Van den Berg E, Newby T (2010) National invasive alien plant survey. Agricultural Research Council, Institute for Soil, Climate and Water, Report No GW/A/2010/21Google Scholar
  32. Krug R, Roura-Pascual N, Richardson D (2010) Clearing of invasive alien plants under different budget scenarios: using a simulation model to test efficiency. Biol Invasions 12:4099–4112. CrossRefGoogle Scholar
  33. Kueffer C et al (2013) Plant invasions into mountain protected areas: assessment, prevention and control at multiple spatial scales. In: Foxcroft LC, Pyšek P, Richardson DM, Genovesi P (eds) Plant Invasions in Protected Areas, vol 7. Invading Nature–Springer Series in Invasion Ecology. Springer, Netherlands, pp 89–113CrossRefGoogle Scholar
  34. Landis JR, Koch GG (1977) The measurement of observer agreement for categorical data. Biometrics 33:159–174CrossRefGoogle Scholar
  35. Latombe G, Pyšek P, Jeschke JM, Blackburn TM, Bacher S, Capinha C, Costello MJ, Fernández M, Gregory RD, Hobern D, Hui C, Jetz W, Kumschick S, McGrannachan C, Pergl J, Roy HE, Scalera R, Squires ZE, Wilson JRU, Winter M, Genovesi P, McGeoch MA (2016) A vision for global monitoring of biological invasions. Biol Cons 213:295–308CrossRefGoogle Scholar
  36. Le Maitre DC, Versfeld DB (1994) Field manual for mapping populations of invasive plants for use with the catchment management system. Department of Environment Affairs, PretoriaGoogle Scholar
  37. Le Maitre DC, van Wilgen BW, Gelderblom C, Bailey C, Chapman RA, Nel J (2002) Invasive alien trees and water resources in South Africa: case studies of the costs and benefits of management. For Ecol Manag 160:143–159CrossRefGoogle Scholar
  38. Le Maitre DC, Richardson DM, Chapman RA (2004) Alien plant invasions in South Africa: driving forces and the human dimension: working for water. S Afr J Sci 100:103–112Google Scholar
  39. Leung B, Lodge DM, Finnoff D, Jason FS, Lewis MA, Lamberti G (2002) An ounce of prevention or a pound of cure: bioeconomic risk analysis of invasive species. Proc Biol Sci 269:2407–2413. CrossRefPubMedPubMedCentralGoogle Scholar
  40. Macdonald IAW, Jarman L, Beeston P (1985) Management of invasive alien plants in the fynbos biome. Foundation for Research Development, Council for Scientific and Industrial ResearchGoogle Scholar
  41. Marais C, Wannenburgh A (2008) Restoration of water resources (natural capital) through the clearing of invasive alien plants from riparian areas in South Africa—costs and water benefits. S Afr J Bot 74:526–537CrossRefGoogle Scholar
  42. McConnachie MM, Cowling RM (2013) On the accuracy of conservation managers’ beliefs and if they learn from evidence-based knowledge: a preliminary investigation. J Environ Manag 128:7–14. CrossRefGoogle Scholar
  43. McConnachie MM, Cowling RM, van Wilgen BW, McConnachie DA (2012) Evaluating the cost-effectiveness of invasive alien plant clearing: a case study from South Africa. Biol Conserv 155:128–135. CrossRefGoogle Scholar
  44. McGeoch MA, Gaston KJ (2002) Occupancy frequency distributions: patterns, artefacts and mechanisms. Biol Rev Camb Philos Soc 77:311–331CrossRefGoogle Scholar
  45. McGeoch MA et al (2010) Global indicators of biological invasion: species numbers, biodiversity impact and policy responses. Divers Distrib 16:95–108. CrossRefGoogle Scholar
  46. McGeoch MA, Spear D, Kleynhans EJ, Marais E (2012) Uncertainty in invasive alien species listing. Ecol Appl 22:959–971. CrossRefPubMedGoogle Scholar
  47. McNaught I, Thackway R, Brown L, Parsons M (2008) A field manual for surveying and mapping nationally significant weeds, 2nd edn. Commonwealth Government-Department of Agriculture, Fisheries and Forestry-Bureau of Rural SciencesGoogle Scholar
  48. Moore JL, Runge MC, Webber BL, Wilson JRU (2011) Contain or eradicate? Optimizing the management goal for Australian acacia invasions in the face of uncertainty. Divers Distrib 17:1047–1059. CrossRefGoogle Scholar
  49. Neethling H, Shuttleworth B (2013) Revision of the Working for Water workload norms. Forestry Solutions, White River, South AfricaGoogle Scholar
  50. Nel J et al (2004) A proposed classification of invasive alien plant species in South Africa: towards prioritizing species and areas for management action: working for water. S Afr J Sci 100:53–64Google Scholar
  51. Ntshotsho P, Prozesky HE, Esler KJ, Reyers B (2015) What drives the use of scientific evidence in decision making? The case of the South African working for water program. Biol Conserv 184:136–144. CrossRefGoogle Scholar
  52. Pressey RL, Visconti P, Ferraro PJ (2015) Making parks make a difference: poor alignment of policy, planning and management with protected-area impact, and ways forward. Phil Trans R Soc B 370:20140280CrossRefGoogle Scholar
  53. Pullin AS, Knight TM, Stone DA, Charman K (2004) Do conservation managers use scientific evidence to support their decision-making? Biol Conserv 119:245–252. CrossRefGoogle Scholar
  54. Pyšek P, Richardson DM (2010) Invasive species, environmental change and management, and health. Annu Rev Environ Resour 35:25–55. CrossRefGoogle Scholar
  55. Rejmánek M, Pitcairn MJ (2002) When is eradication of exotic pest plants a realistic goal? In: Veitch CR, Clout MN (eds) Turning the tide: the eradication of invasive species. IUCN, Gland, pp 249–253Google Scholar
  56. Rew LJ, Pokorny ML (eds) (2006) Inventory and survey methods for nonindigenous plant species. Monana State University Extensions, Bozeman, MTGoogle Scholar
  57. Roura-Pascual N et al (2009) Ecology and management of alien plant invasions in South African fynbos: accommodating key complexities in objective decision making. Biol Conserv 142:1595–1604. CrossRefGoogle Scholar
  58. Roura-Pascual N, Richardson D, Arthur Chapman R, Hichert T, Krug R (2011) Managing biological invasions: charting courses to desirable futures in the Cape Floristic Region. Reg Environ Change 11:311–320. CrossRefGoogle Scholar
  59. Shaughnessy GL (1980) Historical ecology of alien woody plants in the vicinity of Cape Town, South Africa. Doctoral dissertation, University of Cape TownGoogle Scholar
  60. Simberloff D (2009) We can eliminate invasions or live with them. Successful management projects. Biol Invasions 11:149–157. CrossRefGoogle Scholar
  61. Spear D, McGeoch MA, Foxcroft LC, Bezuidenhout H (2011) Alien species in South Africa’s national parks. Koedoe. CrossRefGoogle Scholar
  62. Spear D, Foxcroft LC, Bezuidenhout H, McGeoch MA (2013) Human population density explains alien species richness in protected areas. Biol Conserv 159:137–147. CrossRefGoogle Scholar
  63. Statistics South Africa (2011) Census 2011 Municipal report–Western Cape, PretoriaGoogle Scholar
  64. Taylor HC, Macdonald SA (1985) Invasive alien woody plants in the Cape of Good Hope nature reserve. I. Results of a first survey in 1966. S Afr J Bot 51:14–20CrossRefGoogle Scholar
  65. Taylor HC, Macdonald SA, Macdonald IAW (1985) Invasive alien woody plants in the Cape of Good Hope nature reserve. II. Results of a second survey from 1976–1980. S Afr J Bot 51:21–29CrossRefGoogle Scholar
  66. Tu M (2009) Assessing and Managing Invasive Species within Protected Areas. Protected Area Quick Guide Series, The Nature ConservancyGoogle Scholar
  67. van Wilgen BW et al (2011) National-scale strategic approaches for managing introduced plants: insights from Australian acacias in South Africa. Divers Distrib 17:1060–1075. CrossRefGoogle Scholar
  68. van Wilgen BW, Cowling RM, Marais C, Esler KJ, McConnachie M, Sharp D (2012a) Challenges in invasive alien plant control in South Africa. S Afr J Sci 108:5–7. CrossRefGoogle Scholar
  69. van Wilgen BW, Forsyth GG, Le Maitre DC, Wannenburgh A, Kotzé JDF, van den Berg E, Henderson L (2012b) An assessment of the effectiveness of a large, national-scale invasive alien plant control strategy in South Africa. Biol Conserv 148:28–38. CrossRefGoogle Scholar
  70. van Wilgen BW, Fill JM, Baard J, Cheney C, Forsyth AT, Kraaij T (2016) Historical costs and projected future scenarios for the management of invasive alien plants in protected areas in the Cape Floristic Region. Biol Conserv 200:168–177. CrossRefGoogle Scholar
  71. Watson JEM, Dudley N, Segan DB, Hockings M (2014) The performance and potential of protected areas. Nature 515:67–73. CrossRefPubMedGoogle Scholar
  72. Wilson JR, Ivey P, Manyama P, Nänni I (2013) A new national unit for invasive species detection, assessment and eradication planning. S Afr J Sci 109:01–13CrossRefGoogle Scholar
  73. Wittenberg R, Cock MJW (2001) Invasive alien species: a toolkit of best prevention and management practices. CAB International, WallingfordCrossRefGoogle Scholar
  74. Working for Water (2013) Annual Plan of Operation, Table Mountain National Park, Project: TMNP-SouthGoogle Scholar

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  1. 1.South African National ParksCape TownSouth Africa
  2. 2.Department of Conservation Ecology and EntomologyStellenbosch UniversityStellenboschSouth Africa
  3. 3.Conservation ServicesSouth African National ParksSkukuzaSouth Africa
  4. 4.Centre for Invasion Biology, Department of Botany and ZoologyStellenbosch UniversityStellenboschSouth Africa
  5. 5.School of Biological SciencesMonash UniversityClaytonAustralia

Personalised recommendations