Risk assessment of invasive species - Invasive Species Management - page 26

Table 2.3 Some general characteristics of successfully invaded habitats and
poorly invaded habitats.
Characteristic of successfully
invaded habitats

Examples

1. Low diversity habitats with
available resources

Islands in proximity to the mainland
(Elton 1958; Rejmanek 1996).

2. High diversity habitats with
available resources

Local areas of regions with high light, soil
nutrients, water, and warm temperatures
(Stohlgren et al . 1999, 2005, 2006).

3. Disturbed habitats Post-fi re habitats (Fox and Fox 1986).

Characteristic of poorly invaded
habitats

Examples

1. Areas with a limiting resource Some tropical forests (low light in the

understory), some mangrove forest
(anoxic soil conditions).

2. Areas with extreme climates Extreme deserts, tundra, deep oceans.

3. Areas with atypical environments Serpentine outcrops, hot springs.

cheatgrass invasion is strongly linked to fi re regimes (Keeley and McGinnis 2007).
h is species illustrates how temporal changes in resource availability may be very
important to invasion success (Davis et al . 2000).
h us, identifying invasive species hazards requires an understanding of the
receptor ecosystem (genotypes, species, populations, resource availability, and
disturbance regime), and information on the invading species' traits (Table 2.2).
Invasion is possible only when a vulnerable habitat meets with a species whose
traits allow for establishment, growth, and spread (although lag times between
introduction and spread are common; Mack et al . 2000).
Suitable habitats might be assessed with climate matching approaches
(Chicoine et al . 1985; Panetta and Mitchell 1991; Venevski and Veneskaia 2003).
Climate matching requires knowledge of the climatic conditions in the original
home range of the non-indigenous species and the abundance and distribution of
the species (or genotypes) throughout its range (Morisette et al . 2006). However,
many non-indigenous plant species are found in higher and lower latitudes than
the same species in its home range, suggesting a possibility of an expanded range
in the receptor country (Rejmánek 1996). h is pattern may be due to many
interacting forces (reduced competition, predators, or pathogens) in the recep-
tor country, greater dispersal (perhaps aided by more wind or birds), or diff erent
levels of disturbance in the newly invaded country (Fox and Fox 1986; Hobbs and
Huenneke 1992; Burke and Grime 1996) or fl ooding (DeFerrari and Naiman
1994; Planty-Tabacchi et al . 1996).