Biology Reference
In-Depth Information
high
monitoring
priority
very high
monitoring
priority
low
monitoring
priority
moderate
monitoring
priority
Plant Resources
Fig. 2.3
Relative priorities for early detection monitoring relative to propagule pressure of invad-
ing plants and resource availability
surges in resource availability that would shift a site to a very high priority for
monitoring. These changes can literally occur overnight, most commonly fol-
lowing a major disturbance such as fire, flood, or other agents of vegetation
removal.
Moderate priority
areas occur where there are few or no vectors and pathways
to the site, and thus propagule pressure is low, but resource availability is high
(Fig. 2.3). In this case long-distance dispersal is the primary means by which inva-
sions might occur. These types of sites can quickly upgrade in priority following
major influxes of propagules, which may occur following revegetation or soil sta-
bilization projects (e.g., in seed mixes or straw mulches) or the establishment of
temporary logistical support sites (e.g., fire camps).
Low priority
areas occur where both propagule pressure and resource availabil-
ity are low (Fig. 2.3). However, as mentioned above, these conditions can rapidly
change causing a concomitant upgrade in monitoring priority.
The efficiency of generalized monitoring plans is relatively low compared
with other approaches described later (Fig. 2.1), but so are the costs necessary
to develop them (Fig. 2.4). However, one must remember that time and resources
saved up front with generalized monitoring plans may be eclipsed by the time
and resources lost due to the inefficiencies of the monitoring efforts that follow.
For example, these generalized monitoring plans do not integrate information
about the life history characteristics, specific habitat requirements, or potential
impacts of invading species which could otherwise be used to further focus
monitoring efforts.
