Biology Reference
In-Depth Information
Table 2.3
Information needed to develop predictive models of invasive species in different
phases of the invasion process
A. Pre-introduction and introduction phases
1) Species data
Biogeographic
Native range
Nonnative range
Tendency to be invasive else-
where
2) Environmental data
Climate
Temperature
Precipitation
Productivity
Evapotranspiration
B. Establishment and spread phases
1) Species data
Distribution
Abundance
2) Environmental data
Topography
Elevation
Slope
Aspect
Soils
Structure
Chemistry
Land cover
Vegetation association
Land use
3) “Invasion Theory” data
Disturbance
Grazing
Fire
Logging
Roads & trails
Species pool
Propagule pressure
Site-specific land use
Off-site land use
Neighboring land perimeters
Neighboring land area
Vectors (sources of transport)
The categories within each level are ranked in general order of importance
are often correlated with invasive plant species (Mack and D'Antonio 1998;
Lonsdale 1999). These include factors such as disturbance, propagule pressure, and
the species pool of potential invaders.
2.5.2 Preintroduction Prediction Models for Single Species
Many studies have focused on predicting the likelihood of a species being intro-
duced and becoming established in an area in which it does not yet occur. Until
recently, there has been a great deal of pessimism regarding the success of these
studies (Williamson 1999). However, important advances have been made in recent
