Exotic
Nonnative, or exotic, invasive species introduce risks to forest ecosystems. Invasive species are altering fire regimes, hydrology, nutrient cycling, and productivity of ecosystems (Dukes and Mooney 2004). The invasive species issue is made especially complex because there are thousands of potential invasive species and new and established plants, plant material, pests, and pathogens are in constant movement. Adequate data are not always available to support rigorous quantitative modeling of the different stages of invasion. However, even a semiquantitative rule-based approach can help to identify locations that contain host species susceptible to specific pathogens or insect pests, and where propagules are more likely to enter based on the current locations of the invasive species, ports of entry, and methods of spread.
Unintentional exotic species invasions are often a function of ecological factors, often attacking forests compromised by other threats. Economic factors such as global travel and trade also play a role. In some instances, exotics are introduced intentionally to help irradicate other problematic species. In any case, a review of this section provides the reader with information about decision-making in invasive species management, as well as methods useful for evaluating risks from invasive species by modeling invasive plant, insect, and pathogen species.
To further review exotic invasive species, consider reading the following Environmental Threats Case Studies:
Uncertainty Estimation for Map-Based Analyses
Previsual Detection of Two Conifer-Infesting Adelgid Species in North American Forests
Assessment of Habitat Threats to Shrublands in the Great Basin
Spread of Invasive Plants from Roads to River Systems in Alaska: A Network Model
- Modeling Invasive Plant, Insect, and Pathogen Species : Probabilistic regional risk assessment methodologies were reviewed to identify the methods that are currently in use and are capable of estimating threats to ecosystems from fire and fuels, invasive species, and their interactions with stressors.
- Decision-Making Under Risk in Invasive Species Management: Risk Management Theory and Applications : Invasive species management is closely entwined with the assessment and management of risk that arises from the inherently random nature of the invasion process.
Encyclopedia ID: p3283
