Impacts of climate change on invasive Lantana camara L. distribution in South Africa
Climate change and invasive species are now seen as two major contributors to global biodiversity change. The combined effects of these two factors have serious implications for biodiversity and agriculture. Lantana camara L. (sensu lato) (lantana) is a woody shrub that is highly invasive in many countries of the world including South Africa where it has a profound impact on biodiversity, water resources and agriculture. Strategies to manage and control this highly noxious weed will benefit from information on its likely potential distribution under current and future climate. CLIMEX, a species distribution modelling software, was used to develop a process-oriented niche model to estimate its potential distribution under current and future climate scenarios. Model calibration was carried out with phenological observations and geographic distribution records of lantana. The potential distribution of lantana under current climate showed a good match to its current distribution in South Africa. Under future scenarios, the climatically suitable areas for lantana were projected to contract in the northern provinces of Limpopo and Mpumalanga as well as coastal areas of Western Cape Province. However, lantana’s potential distribution may expand further inland into new areas in KwaZulu-Natal and Eastern Cape provinces. The results suggest that lantana management initiatives in areas where climatic suitability is likely to decline should focus on controlling the density of invasion rather than curbing range expansion. On the other hand, areas where climatic suitability is projected to increase will require ongoing monitoring to prevent further range expansions.
Key words: CLIMEX, niche models, species distribution models, biotic invasions, weeds, climate change.