Biology Reference
In-Depth Information
prolifically reproduces itself (AXN, personal observation). Inducing sterility, either
by breeding or molecular tools, could diminish invasion risk of a seed-dispersed spe-
cies that, due to its popularity and economic impact, would not be removed from the
ornamental horticulture trade. However, extensive research on the efficacy and stabil-
ity of sterility systems as well as the realized prevention of invasiveness should be
conducted before sterile, noninvasive cultivars are released (Anderson et al. 2006).
9.5.4
Volunteers to Assist in Controlling Invasive NIS
Volunteers are a valuable resource for early detection of invasive NIS (Simberloff 2003;
Wittenberg and Cock 2001). Personnel associated with the horticulture and landscaping
industries are well qualified to detect emergent invasive species. In addition to those
employed to survey and scout for spreading NIS, Wittenberg and Cock (2001) suggest
that gardeners, landscape managers, fisherman, land surveyors, hikers, and others who
venture into natural habitats be trained to identify or seek identification for known or
new invasive NIS. The Federal Interagency Committee for the Management of Noxious
and Exotic Weeds in conjunction with other governmental, state, and local partners has
proposed a National Early Detection and Rapid Response System of invasive plants in
the USA (Westbrooks 2004). Early detection and reporting of suspected new invasive
species by volunteers is the foundation of the system. Hegamyer et al. (2003) present
several successful case studies on the use of volunteers for early detection of invasive
species, some of which were performed by Extension Master Gardeners (EMGs). In the
USA, there are approximately 90,000 active EMGs trained in aspects of plant science
and land stewardship. Thus, EMGs potentially represent a sizable, effective volunteer
force, especially in view of their knowledge of plant science and garden species.
9.5.5
Controlling Invasive NIS - Prevention and Eradication
The horticulture industry is uniquely situated to work with the scientific community
to more accurately predict which NIS will be invasive. Mack (2005) recommends that
we must go beyond the traditional use of invasive plant traits and the invasive history
of species (criteria promoted in the
Voluntary Code of Conduct for Nursery
Professionals
) and undertake field trials that (1) identify those species that easily self-
propagate (sexually or asexually) with minimal or no cultivation, and (2) identify and
report species that routinely escape cultivation. These measures will yield valuable
data on those species that are apt to establish populations outside their planted range.
Mack (2005) encourages nurseries to serve as test sites, a capacity that nurseries
already serve in evaluating plant traits, to determine those species that require mini-
mal or no cultivation and have the capacity to emigrate from their planted sites and
generate new populations. Simberloff et al. (2005) proposed that the decision of
whether a species should be introduced should be based on “a solid understanding of
what regulates populations in their native range.” Both of these authors readily admit
