Luke Humphrey completed his MSc at Rhodes University in 2016, in the Department of Ecomomics and Economic History. His theses, titled ‘The Economic Implications of Robinia pseudoacacia L. (black locust) on Agricultural Production in South Africa’ was supervised by Prof Gavin Fraser and Dr Grant Martin.

Thesis Abstract
Robinia pseudoacacia L. (black locust) is an invasive deciduous, broad-leaved tree that has the potential to be widely distributed across South Africa. Robinia pseudoacacia has invaded all nine South African provinces, with large infestations in the Eastern Cape, KwaZulu-Natal, Free State and Gauteng provinces. Because R. pseudoacacia can spread and thrive in a variety of habitats and resists control, the distribution of the invasive tree into grazing land poses a problem for landowners. The potential economic impacts of R. pseudoacacia on agricultural production stem from the tree’s ability to reduce the carrying capacity for livestock. This study estimated the potential economic implications of R. pseudoacacia on agricultural production in South Africa, specifically the livestock sector. Robinia pseudoacacia’s potential distribution was calculated using a maximum-entropy predictive habitat model, using MaxEnt. The distribution of livestock, based on grazing capacity (ha/large stock unit), in South Africa was then determined. The potential direct economic impacts were estimated by assessing the impact of the potential distribution of R. pseudoacacia on the carrying capacity for livestock. The results showed that an infestation of R. pseudoacacia has the potential to reduce the total gross margin in the livestock sector by between approximately R135 million and R674 million, dependent on the level of invasion. The potential levels of foregone income and business activity found in this study reaffirm the need to devote resources to develop a viable, economical and effective control.

A copy of this thesis is available here.

Last Modified: Wed, 22 Aug 2018 13:43:56 SAST