The dissemination or geographic spread of individuals of a plant or animal population.
- Invasive crayfish in the Pacific Northwest [More info]
- These organisms have negative effects on local ecosystems, but we don't yet know how extensively they have spread. Here is a key to help people identify them.
- The saga of leafy spurge (Euphorbia esula) in the northern Great Plains [More info]
- Explains why this invasive plant is successful in taking over land in many northern states, and what might be done to impede its dominance.