Modelling Opuntia fulgida invasion in Zimbabwe

Abstract

The invasion of agro-ecosystems, as well as natural ecosystems by Opuntia fulgida, compromises the ability of these systems to provide goods and services to the society and this has a direct bearing on human livelihoods. Yet, not much is known about the current, as well as potential distribution of this invasive alien species in invaded landscapes, such as the southwestern districts of Zimbabwe. In this study, we apply maximum entropy species distribution modelling to georeferenced occurrence data and a set of predictor variables (that is, climatic, ecological and demographic variables) in order to generate the first distribution maps of O. fulgida in Zimbabwe. Our results suggest that a total of 17 districts in Zimbabwe are vulnerable to invasion by O. fulgida and communal lands are most susceptible to invasion relative to other land tenure systems. We discuss the possible mechanisms of spread and highlight threats to livestock production systems posed by this invasive alien species.

Keywords:

• alien species
• cactus
• environmental security
• maximum entropy
• livestock productivity
• rangeland

ACKNOWLEDGMENTS

We thank the Environmental Management Agency of Zimbabwe (EMA) and the University of Zimbabwe for providing funds to collect data on the occurrence of alien cacti in Zimbabwe. We are also grateful to Amkela Sidange, Maxwell Maturire, Tawanda Chinogwenya of EMA, and Christopher Chapano of the National Herbarium and Botanic Garden, Zimbabwe for field assistance.

ORCID

Timothy Dube http://orcid.org/0000-0003-3456-8991