Introduced and invasive cactus species–a global review

Understanding which species are introduced and become invasive are central questions in invasion science. In this sense, the cactus family is an interesting case study. Only 57 of the 1922 cactus species are currently recorded as invasive. There are three invasion hotspots: South Africa, Australia, and Spain. However, in a new study published in AoB PLANTS, Novoa et al. identified large areas of the world with suitable climates for cactus invasions that are at risk of future invasion – in particular parts of China, eastern Asia and central Africa. The invasive taxa represent an interesting subset of the total pool: they occur in two of the three major phylogenetic clades and in 13 of the 130 cactus genera, and possess four of the 12 cactus growth forms. Moreover, invasive species tend to have significantly larger native ranges than non-invasive species, and none of the invasive species are of conservation concern in their native range. These results suggest fairly robust correlates of invasiveness that can be used for proactive management and risk assessments.