Geographic range expansions by plants and animals have presented a number of puzzles to scientists. The first of these is known as Reid’s paradox: species ranges often expand much faster than expected from normally observed dispersal rates.
Quantifying the amount of genetic diversity and how it is distributed within and between populations (genetic structure) has become a major focus in invasion biology. Population genetic structure can be useful as a proxy for the introduction history of a species, e.g. to differentiate between multiple introductions vs. single introductions.
Environmental managers need to understand the factors that control community composition at different spatial and temporal scales to formulate appropriate guidelines for management. To this end, community assemblage rules explain how species are “packed” in a community and how community composition is related to the niche and traits of species.
Protected areas are increasingly important in the maintenance of species, ecosystems and the services they provide; at the same time, however, invasions by alien species are accelerating, undermining the conservation value of protected areas and preventing them from achieving their goals. If the invasion of alien species into protected areas is to be prevented, or at least minimised, then a detailed understanding of their drivers is required.
South Africa is world renowned as a leader in the science and management of biological invasions, but has been lagging behind in one key area—eradication. As of 2010 South Africa had ~8750 introduced plant taxa, 660 recorded as naturalised, 198 included in invasive species legislation, but only 64 subjected to regular control.