Biology Reference
In-Depth Information
Table 2.2
Information needed to develop prioritized lists of sites to protect from invasion by
nonnative species
A. Susceptibility to invasion
1) Intrinsic (site-specific)
Nonnatives richness
Nonnative distribution
Nonnative abundance
Land use
Spatial
Vegetation
community
Disturbance
Historic
Contemporary
2) Extrinsic (off-site)
Vectors and pathways
Neighbor perimeter
Neighbor area
Land use
Roads
Trails
Watercourses
Disturbance
Contemporary
3) Invasion Rates
Temporal trend in nonnative
species accumulation
B. Conservation value
1) Hotspots
2) Endemics
3) T & E species
4) Rare community types
5) Sensitive areas of other value
e.g. cultural or recreational
C. Management feasibility
1) Management constraints
e.g. in wilderness
2) Site accessibility
The categories within each level are ranked in general order of importance
become established. Management of established species not yet spreading should
be focused on eradication. Attention should be given not just to sites with larger
infestations but satellite populations as well which often serve as propagule sources
from which larger infestations can develop and spread. Species that are actively
spreading are especially hard to deal with. A strategy with dual objectives of con-
taining further spread and reducing density is recommended, but resources may not
always allow this. If resources are limited, the decision to focus on containment vs.
control will be determined by how rapidly the species is spreading.
2.5 What can be Done with Geo-Referenced Abundance Data?
Geo-referenced abundance data provide the opportunity to develop the most effi-
cient types of early-detection monitoring plans possible. Specifically, these types of
data can be used to develop predictive models to help focus monitoring efforts
