Determining the efficiency of contractors in clearing invasive alien plant species : the case of the Mopani District, Limpopo province, South Africa

Abstract

This study assesses the efficiency of contractors hired by the Natural Resource Management programme of the Department of Environmental Affairs (DEA:NRM) in clearing invasive alien plants. We analyse the efficiencies of 49 contractors in two catchments for three time periods, namely 2003 to 2006, 2007 to 2010 and 2011 to 2014. It was found that the size of the contract areas allocated for clearing decreased slightly from 2003 to 2014, while the unit costs (in real terms) have increased considerably. A reason for the increase in the costs can be attributed, among others, to the increase in the infestation densities of stands, because the more densely the infestation is, the more time is required to clear a hectare (Pd/ha) and hence the higher the costs of clearing (R/ha). This is an important observation, as it suggests that focusing on early restoration will further accelerate the clearing of invasive alien plants (IAPs) towards achieving the desired targets.