All alien species cause changes to the ecosystems to which they are introduced. Such impacts are of many types - some are dramatic and obvious and can easily be classified as desirable or undesirable. However, for the vast majority of alien species, no information on impact is available. This greatly complicates the task of objectively assigning priority to management.
Eradication of invasive alien plants requires that all populations of the plants have been found and every plant removed. This entails intensive searching, which often comes at a great expense. Maps that show where species are likely to occur are useful for guiding searches, and may reduce the costs and increase the success of eradication operations. Such maps are based on models that explore the links between plant distributions and climatic factors in order to predict where the plants might occur.
Recently published C·I·B research conducted in association with the International Polar Year ‘Aliens in Antarctica’ project has measured the propagule load carried in the clothing and gear of researchers and visitors to the Antarctic region.
The management of invasive species is made more complex when more than one invasive species is present in a given ecosystem at the same time. Several invasive species may have a greater effect than one species does alone and there can be synergistic effects that result in a cascade of impacts and a large change in the way the ecosystem functions.
Fruit flies are major economic pests throughout the world, causing huge economic losses to commercial fruit production. Some of the most notorious invasive species cause widespread damage by puncturing the fruit during egg laying and leaving the larvae to develop in the fruit.