Assessing the effectiveness of invasive alien plant management in a large fynbos protected area
Date
2017
Journal Title
Journal ISSN
Volume Title
Publisher
AOSIS Publishing
Abstract
Background: Concern has been expressed about the effectiveness of invasive alien plant (IAP)
control operations carried out by Working for Water (WfW). South African legislation now also
requires reporting on the effectiveness of IAP management interventions.
Objectives: We assessed the effectiveness of IAP management practices in a large fynbos
protected area, the Garden Route National Park, South Africa.
Methods: We undertook field surveys of pre-clearing IAP composition and the quality of
treatments applied by WfW during 2012–2015 in 103 management units, covering 4280 ha. We
furthermore assessed WfW data for evidence of change in IAP cover after successive treatments,
and adherence to industry norms.
Results: Despite the development of detailed management plans, implementation was poorly
aligned with plans. The quality of many treatments was inadequate, with work done to standard
in only 23% of the assessed area. Problems encountered included (1) a complete absence of
treatment application despite the payment of contractors (33% of assessed area); (2) treatments
not being comprehensive in that select areas (38%), IAP species (11%) or age classes (8%) were
untreated; (3) wrong choice of treatment method (9%); and (4) treatments not applied to standard
(7%). Accordingly, successive follow-up treatments largely did not reduce the cover of IAPs.
Inaccurate (or lack of) infield estimation of IAP cover prior to contract generation resulted in
erroneous estimation of effort required and expenditure disparate with WfW norms.
Conclusions: We advocate rigorous, compulsory, infield assessment of IAP cover prior to
contract allocation and assessment of the quality of treatments applied prior to contractors’
payment. This should improve the efficiency of control operations and enable tracking of both
the state of invasions and effectiveness of management.
Description
CITATION: Kraaij, T., et al. 2017. Assessing the effectiveness of invasive alien plant management in a large fynbos protected area. Bothalia - African Biodiversity and Conservation, 47(2):a2105, doi:10.4102/abc.v47i2.2105.
The original publication is available at http://abcjournal.org
The original publication is available at http://abcjournal.org
Keywords
Introduced organisms
Citation
Kraaij, T., et al. 2017. Assessing the effectiveness of invasive alien plant management in a large fynbos protected area. Bothalia - African Biodiversity and Conservation, 47(2):a2105, doi:10.4102/abc.v47i2.2105