Monitoring & evaluation

“The WfW Programme has made no provision for routine project monitoring or evaluation in relation to ecological responses to alien clearing.  Even research in this regard is scant. Currently performance is measured on alien clearing efficiency (hectares cleared) rather than on degree of vegetation recovery. Without measuring the impacts of clearing, managers have no idea whether they are using the optimal approach, degrading or improving ecological integrity” - WfW External Evaluation (2003).
  • Preston et al. (2018) assessed the impact of invasive alien plants on water provision in two catchments
  • Ntshidi et al. (2018) concluded that the water use of poplar invasions is significantly lower than that of other riparian invasions
  • Kraaij et al. (2017) assessed the effectiveness of invasive alien plant management in the Garden Route National Park
  • Fill et al. (2016) assessed the effectiveness of invasive alien plant management in the Upper Berg River catchment
  • Van Wilgen et al. (2016) documented the historical costs and extent of efforts to control invasive alien plants in the protected areas of the Cape Floristic Region and estimated the resources that would be needed to bring the problem under control within a reasonable timeframe
  • Goergans (2016) calculated the impacts of different degrees of alien plant invasion on yields from the the Western Cape Water Supply System
  • Ntshotsho et al. (2016) explored the success of invasive alien plant clearing projects of the Working for Water Programme, using three case studies
  • Dzikiti el at. (2016) quantified the savings from clearing invasive alien Eucalyptus camaldulensis using in situ and high resolution remote sensing data in the Berg River Catchment
  • Van Wilgen and Wannenburgh (2016) reviewed the achievements and challenges in the Working for Water programme
  • Le Maitre et al. (2016) estimated the impacts of invasive alien plants on water flows in South Africa
  • reviewed the information on the impacts of invasions on surface runoff and groundwater resources at stand to catchment scales and covering a full annual cycle
  • Meijninger & Jarmain (2014) assessed the impact that invasive alien plants, and the clearing thereof by Working for Water, has on the availability of water resources in the Western Cape and KwaZulu-Natal provinces
  • Le Maitre et al. (2012) simulated and quantified the effects of plant invasions on land-cover, hydrological soil characteristics and catchment responsiveness on flow regulation using a hydrological model
  • McConnachie et al. (2012) evaluated the cost-effectiveness of Working for Water in reducing invasive alien plant cover in the Krom and Kouga river catchments over 7 years
  • Van Wilgen et al. (2012) assessed the effectiveness of the Working for Water programme over the past 15 years, by reviewing data from three national-level estimates of the extent of invasion, records of the costs and spatial extent of invasive species control operations, assessments of the effectiveness of biological control, and smaller-scale studies.
  • De Lange & Van Wilgen (2010) found that although an estimated R6.5 billion was lost every year due to invading alien plants, this would have amounted to an estimated additional R41.7 billion had no control been carried out
  • Hope (2009) investigated the viability of relating annual river yields to remotely sensed changes in vegetation cover in a large mountainous fynbos catchment
  • Levendal et al. (2008) developed monitoring and evaluation guidelines for the biophysical goals of Working for Water
  • Van Wilgen et al. (2008) conducted a biome-scale assessment of the impact of invasive alien plants on ecosystem services
  • Dye and Jarmain (2004) reviewed relevant available information on rates of evaporation from black wattle and from grasslands and fynbos shrublands
  • Dye et al. (2001) concluded that the removal of riparian wattle and its replacement by indigenous herbaceous plants may result in significant reductions in annual evapotranspiration, and could very likely lead to streamflow enhancement
  • Prinsloo and Scott (1999) describe the changes in streamflow following the removal of invasive wattle from riparian zones during the dry summer months in three small catchments in the Western Cape
  • Dye and Poulter (1995) conduced a field demonstration of the effect on streamflow of clearing invasive pine and wattle trees from a riparian zone