Invader potential

In conservation biology, invader potential is the qualitative and quantitative measure of a given invasive species probability to invade a given ecosystem. Exotic species with high invader potential are ones with high tolerance of different climates, dissolved oxygen content (for aquatic organisms), high propagule pressure and species with a large number of individuals introduced. The last factor is called a transport vector, for instance, sea lampreys and zebra mussels were transported into the Great Lakes through the vector of ballast water in ships. Transport vector is one of the most important factors, because if a large enough number of individuals are transported to an area that they cannot thrive in, a mutation within that population to thrive in the new ecosystem is more likely.

Most invaders are adapted to disturbed areas, so ecosystems that have been disrupted or roadside ditches are susceptible to invasion.

Climate matching is one of the most common measures of invader potential. Mostly exotic species that have already exhibited invasive traits are studied.

Biotic resistance is a controversial concept in invader potential. Small scale studies have borne the concept of diversity resistance, that diverse ecosystems resist invasions better than less diverse ecosystems. However, evidence on regional scales finds a positive correlation between diversity and number of invasions. The exact interpretation of these studies is unclear.

References

• Kolar, C. S.; Lodge, D. M. (2002). "Ecological Predictions and Risk Assessment for Alien Fishes in North America". Science 298 (5596): 1233–1236. doi:10.1126/science.1075753. PMID 12424378.