Abstract
Regulations provide the legal basis for managing biological invasions, but assessments of their effectiveness are rare. To assess the influence of national and local regulations on alien plant species richness and composition in a large protected area (Kruger National Park [KNP], South Africa) we surveyed tourist camps and staff villages for alien ornamental plants. We compared our survey results in 2020 with a previous survey carried out between 1999 and 2003, in the context of national regulations on alien plants promulgated in 2001 and 2014. The number of alien plant species recorded in KNP has almost doubled since the first survey (from 231 to 438), although there has been significant species turnover (93% average replacement across all camps). Importantly, however, both the number of listed and regulated alien plant species found in KNP, and their species richness per camp, have declined (by 38% overall and by 56% per camp). This suggests that regulations are effective. In contrast, the number of unregulated ornamental alien species recorded has increased (by 157% overall). This is likely partly due to an increase in survey effort. Alien species regulations provide clear guidance for conservation managers, and there are promising signs of their effectiveness in directing management in KNP. However, converting alien species lists into priorities for control or regulation will continue to require risk analyses sensitive to park user needs. We advocate for better monitoring of the effectiveness of the regulations, and for the results of such monitoring to be interpreted based on local management needs and concerns.
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Data availability
Data are available from the Zenodo Digital Repository (https://zenodo.org/record/6957337#YvDHzBxByxl).
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Acknowledgements
We acknowledge logistical support from the DSI-NRF Centre of Excellence for Invasion Biology, Kruger National Park, South African National Parks, and SANBI.
Funding
We received financial support from the DSI-NRF Centre of Excellence for Invasion Biology, Kruger National Park, South African National Parks, SANBI, the Oppenheimer Memorial Trust (grant 18576/03 to DMR), and the Millennium Trust. AD, JRUW, and SK thank the South African Department of Forestry, Fisheries, and the Environment (DFFE) for funding, noting that this publication does not necessarily represent the views or opinions of DFFE or its employees. DMR was supported by Mobility 2020 project CZ.02.2.69/0.0/0.0/18_053/0017850 (Ministry of Education, Youth and Sports of the Czech Republic) and long-term research development project RVO 67985939 (Czech Academy of Sciences).
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JHK, AD, JRUW, LCF, SK, and DMR devised the project and developed the main conceptual ideas; JHK and AD planned and conducted all field work and data collection; GRN assisted with plant identification; JHK and AD analysed the data in consultation with the other authors; JHK and AD wrote the first draft; JHK, AD, JRUW, LCF, SK, GRN, and DMR edited all subsequent drafts; all authors contributed to the final manuscript.
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Keet, JH., Datta, A., Foxcroft, L.C. et al. Assessing the level of compliance with alien plant regulations in a large African protected area. Biol Invasions 24, 3831–3844 (2022). https://doi.org/10.1007/s10530-022-02883-7
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DOI: https://doi.org/10.1007/s10530-022-02883-7