Assessing the Effects of Invasive Alien Species on Rural Livelihoods: Case Examples and a Framework from South Africa

Abstract

The detrimental impacts of invasive alien species (IAS) on ecosystem goods and services and local and regional economies are well documented. However, the use of IAS by rural communities is little understood, and rarely factored into IAS control programmes. Understanding the use of IAS by rural communities and factoring these into cost-benefit models is complex, depending upon a range of local-level attributes such as the time since invasion, abundance, and local-level costs and benefits. This paper reports on two case studies examining the role of IAS in rural livelihoods in the Eastern Cape, South Africa. In both cases, rural communities made widespread consumptive use of the IAS and generally would prefer higher densities, except in certain key localities. Several households traded in IAS products to generate supplementary income. We present a conceptual framework to guide interpretation of these and future case studies, considering attributes such as time since invasion, the competitiveness of the species, and the relative costs and benefits.

Stakeholder perceptions and practices regarding Prosopis (mesquite) invasions and management in South Africa

“…One framework suggests that the abundance of invasions is the dominant factor influencing perceptions (Shackleton et al 2007). Other factors such as biophysical characteristics of the local environment, potential uses, growth form of the plant, mode of introduction, social context of the area (socioeconomic status, local policies, and land tenure), and familiarity with the invasive species clearly also shape perceptions and use of invasive aliens (Kull et al 2011;Rai and Scarborough 2014).…”

“…This is in agreement with other sources that have shown that Prosopis invasions in the Northern Cape province increased from approximately 128 000 ha in 1974 to 1.5 million ha in 2007, and that the extent increased by around 8 % per annum from 1974 to 2007 (Van den Berg 2010; van Wilgen et al 2012). This will increase costs and reduce benefits, thereby increasing human vulnerability in the future (Shackleton et al 2007;Wise et al 2012). Most people (98 %) would like to see Prosopis populations reduced in the study area (Table 5).…”

“…Insights on the human dimensions of invasive alien species are essential for effective decision making; in many cases, complex social issues delineate the full suite of benefits and costs associated with invasions (García-Llorente et al 2008). Research is needed to evaluate stakeholder knowledge, perceptions, practices, awareness, and wants and needs relating to biological invasions (Shackleton et al 2007;Eiswerth et al 2011;Kull et al 2011;Rai and Scarborough 2014). This is particularly important for invasive species that were introduced for specific purposes and where complex conflicts of interest now exist due to the provision of valuable consumptive and nonconsumptive services (Shackleton et al 2007;Low 2012a;Dickie et al 2014;van Wilgen and Richardson 2014).…”

“…Many invasive alien species such as Australian acacias, Opuntia ficus-indica and Prosopis provide services such as fuelwood, medicine and edible products to local communities (de Neergaard et al 2005;Pasiecznik et al 2006;Shackleton et al 2007Shackleton et al , 2011. In the semi-arid parts of Brazil, the direct-use services provided by invasive species were seen as more important for local communities than those from native species (Dos Santos et al 2014).…”

“…However, understanding of the social dimensions of Prosopis invasions is poor, and this is thwarting attempts to implement effective management to reduce the costs while, where possible, maintaining some or all of the benefits (Richardson 1998). Key factors that influence human perceptions of invasive alien species generally relate to the abundance of the invader, the services it provides, the time since introduction, the mode of introduction, and many sociopolitical features of human societies (Shackleton et al 2007;Kull et al 2011;Rai and Scarborough 2014).…”