Dr Ana Novoa1, Prof Petr Pyšek1,2
1The Czech Academy of Sciences, Institute of Botany, Department of Invasion Ecology, Pruhonice, Czech Republic, 2Department of Ecology, Faculty of Science, Charles University, Prague, Czech Republic
Due to their resilience to drought, high temperatures and poor soils, cactus varieties, especially Opuntia ficus-indica, are being widely proposed as an ideal crop for agricultural development in areas affected by climate change or desertification. Opuntia ficus-indica has a long history of introduction outside its native range, where it can also cause a variety of negative impacts and become invasive. However, since the 19th century, spineless varieties of O. ficus-indica have been developed through plant breeding. Due to their lack of spines, these varieties can be grazed by herbivores and so are generally thought not to become invasive which makes them suitable for introduction as crops. The Food and Agriculture Organization of the United Nations (FAO) are increasingly promoting the use of these varieties to reduce the impacts of climate change and land degradation on food security in developing countries. Nevertheless, if these varieties were to revert to the spiny form, instead of alleviating climate change, they could lead to impacts on biodiversity, ecosystem functioning, resource availability, national economy, and human health. We explored the likelihood of reversion to spiny forms of nine common spineless O. ficus-indica cultivars. Almost all tested spineless varieties reverted to spiny forms. This calls for urgent need of further research and to develop a risk analysis procedure for the spineless O. ficus indica cultivars.
Ana Novoa is a scientist at the Academy of Sciences of the Czech Republic. Her research to date has been focused on the ecology and management of alien species. She is an Associate Editor for the journals Biological Invasions, KOEDOE, and Management of Biological Invasions.