Biology Reference
In-Depth Information
introduction, widely propagated and distributed taxa will have an unknown poten-
tial for harming the environment.
The probability of invasion increases with time (i.e., residence time of NIS)
because more propagules are spread and the probability of founding new popula-
tions increases (Rejmanek et al. 2005). Thus, the mass propagation, distribution,
and planting of a species serve to greatly increase invasion pressure and is most apt
to shorten the lag time for a potentially invasive NIS to become invasive.
Additionally, “invasional meltdown” may decrease this lag time for invasion and is
another reason why the ornamental horticulture industry should take a more active
role in invasive NIS issues. For example, figs cannot reproduce without the pres-
ence of a coevolved pollinator. Of the 60 species of fig (
Ficus
) occurring in south
Florida, 20 of them are widely planted, and the specific pollinating wasps for three
of these widely planted species were recently introduced into the area. The intro-
duction of these three nonnative species of pollinating wasps has resulted in the
reproduction of all three associated, introduced fig species and the rapid spread of
one of these species (
Ficus microcarpa
) (Kaufman et al. 1991).
9.5
What Should the Ornamental Horticulture Industry Do?
9.5.1 Voluntary Regulation
The ornamental horticulture industry has taken steps to address and mitigate its role
in being purveyors of invasive NIS. In 2001, a coalition of horticulture entities met
at the Missouri Botanical Garden for a meeting entitled “Linking Ecology and
Horticulture to Prevent Plant Invasions” and formulated the Saint Louis declaration,
which consisted of a two-part treaty, Findings and Proceedings and Voluntary
Codes of Conduct (Baskin 2002). The latter was a list of measures for various sec-
tors of the ornamental horticulture industry (government, nursery professionals,
gardening public, landscape architects, and botanic gardens and arboreta) “to curb
the use and distribution of invasive plant species through self-governance and self
regulation.” A follow-up meeting “Linking Ecology and Horticulture to Plant
Invasions II” was held in Chicago in 2002 (Fay 2003). Many of the major ornamen-
tal horticulture organizations endorsed the Voluntary Codes of Conduct. These
codes have helped to develop measures to reduce the sale of invasive NIS and form
partnerships such as the California Horticultural Invasives Prevention (Cal-HIP,
http://www.cal-ipc.org/landscaping/calhip.php. Accessed 23 May 2008) (California
Invasive Plant Council) and Washington State Nursery and Landscape Association
Task Force (Washington Invasive Species Coalition, http://www.invasivespeciesco-
alition.org/GardenPlants/TaskForce. Accessed 9 June 2008). In 2005, the
Horticultural Research Institute, the research arm of the ANLA, granted 15% of
their $220,000 research budget to invasive plant research (ANLA - HRI, http://
www.anla.org/pdffiles/Projlistingwcharts.pdf. Accessed 23 May 2008). An exam-
ple of proactive behavior regarding invasive NIS occurred in Florida in which
