Assessing invasive alien plant impacts on ecosystem services in the City of Cape Town
Claire A. Giovanelli, Mirijam Gaertner1, Patrick O’Farrell2, Karen Esler1,3
1Centre for Invasion Biology, Stellenbosch University; 2CSIR, Biodiversity and Ecosystem Services Research Group; 3 Department of Conservation Ecology and Entomology, Stellenbosch University
South Africa is following the global trend of urbanisation. This increases the need for planning and service provision within ever expanding cities. Ecosystems play a large role in the provision of services for human health and wellbeing. Ecosystem services include supporting functions (e.g. nutrient cycling and pollination to maintain biodiversity) which form the basis of all other services such as provisioning (e.g. water regulation and waste assimilation), regulating (e.g. control of climate and disease control) and cultural (e.g. spiritual and recreation). One of the largest direct drivers of ecosystem degradation and change is caused by invasive alien plants (IAP) which alter ecosystem functions, transform habitats and decrease biodiversity. Often these changes have a negative impact on ecosystem services. The impact of IAP in the provision of ecosystem services in the urban environment has received little attention especially in developing countries.
The aim of this study is to determine the impacts of invasive alien plants on ecosystem services in the City of Cape Town and investigate the associated socio-economic impacts. In this study we identify key ecosystem services in Cape Town, categorise IAPs according to the fynbos vegetation types found within the city and determine the human beneficiaries of ecosystem services. A framework is generated using current literature and databases. This study will be of interest to IAP managers in urban environments.