Biology Reference
In-Depth Information
to evaluate landscape invasibility, and information on the natural, cultural, recrea-
tional, and/or economic values at potential risk due to plant invasions. In contrast,
there is a much wider range of information availability regarding invasive species
data. In this chapter, we focus primarily on what to do with different amounts of
invasive species data.
There are typically three scenarios relative to the availability of invasive species
data within or adjacent to a management unit:
1. There are no data on invasive species.
2. There are species lists of invasives.
3. There are georeferenced abundance data for invasive species.
Because data limitations are a fundamental consideration in developing any moni-
toring plan, we organized this chapter around these three scenarios. As data quan-
tity and quality increase so too do their range of potential applications for designing
early monitoring plans. Accordingly, the sections of this chapter that deal with each
of the three scenarios presented above become progressively longer and more
detailed. We realize that the most common situation involves having no data or only
having species lists. However, we devote significant attention to what can be done with
georeferenced data because scientists advising land managers often emphasize the
need for this type of data. We feel it necessary to explain just how resource inten-
sive this process of generating and using georeferenced data is, so that those who
may be considering this path can better determine whether the effort required is
worth the potential improvement in monitoring efficiencies that may result. We
hope that this approach will ultimately make it easier to translate the information
we present into practice.
2.3
What can be Done in the Absence of Species Data?
It is becoming increasingly rare that there are absolutely no species data available
within or near a land management unit, either because most have some sort of spe-
cies inventory (e.g., plots used to validate vegetation maps) or land managers have
access to regional lists of invasive plant species (e.g., invasive plant council lists).
Even if species data are present, the resources may not be available to compile,
synthesize, and evaluate the data. In the event that species data or resources to proc-
ess the data do not exist, all efforts to develop efficient monitoring plans must rely
on general invasion theory to develop a generalized monitoring plan (Fig. 2.2).
2.3.1 General Invasion Theory
Numerous interacting factors influence rates and extent of biological invasions, and
their relative effects have been widely discussed and debated (Hobbs and Huenneke
1992; Lonsdale 1999; Williamson 1999; Davis et al. 2000; Rejmanek et al. 2005).
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