Transcript Invasive Plants

Invasive Plants
Monica Vernon
Ecol 474
What is an Invasive Plant?
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An invasive plant species is
defined as one that has or is
likely to spread and develop
self-sustaining populations,
and become dominant or
disruptive.
Invasive plants interfere with
ecosystem function and are
a serious threat to
biodiversity and productivity
in different habitats.
Also Known As
o
Invasive plants
are also known
by names such
as weeds, and
include
adjectives such
as alien, noxious,
exotic, transient,
or foreign, to
name just a few
Why Does it Matter?
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Invasive plants are second only to habitat loss and
degradation in endangering native plant species. They are
also the second most serious threat to biodiversity in all
ecosystems.
Negative effects of the invasive plants can be seen in
many factors including competition for resources,
hybridization, introduced or increased nitrogen fixation,
and increased sedimentation among other things.
Invasive weeds in wetland areas cause problems for water
resource managers, can inhibit drainage and interfere with
intended uses for a body of water, and also provide a
habitat for vectors of diseases. A recent estimate on the
cost of invasive plants was put at $35 billion a year.
History
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Plants original uses were medicinal and agricultural,
but over time with society acquiring more disposable
wealth, they also became a hobby with ornamental
gardening and experimentation. Experimental
gardens, commercial nurseries, and international
trade of plants and seeds flourished
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Today’s interest in horticulture and plant exploration is
one of the pathways of invasive plant introduction and
spread. The United States has encountered various
problems for over a century due to invasive plants,
largely because of ornamental use or intentional
introduction
How are They Being Spread?
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The Internet
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Rarely differentiates between the plants that
are invasive and those which are not.
Every aquatic plant that was listed on the
federal or state noxious weed list was found
on the internet. Because many are pretty and
easy to grow there are problems with them
being sold.
Easy access to the internet has increased
the spread of invasive species. Species may
now repeatedly, on larger scales than ever, be
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introduced to new areas
How are they Being Spread?
 Botanical Gardens and Arboreta’s
 Usually more knowledgeable and have greater lengths of
time in observation of plant behavior, issues still arise such
as invasive species being mistaken for non-invasive and
problems with a period known as lag time.
 One may believe a new plant safe and noninvasive due to
the fact it was observed for a period of time without
displaying characteristics of an invasive plant, but many
invasive plants do not begin to invade for many years. Lag
time for many species has still not been determined. A few
reasons for this is the fact some of the invasive plants only
become invasive after changes in environment, genetic
changes within the plant, or introduction of pollinator.
How are They Being Spread?
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Many
Hobbyists/Nurse
ries usually don’t
have the knowledge
to recognize invasive
species. Even those
who have some
knowledge of
invasive species very
often misidentify an
invasive species for
one they think to be
safe.
What Can Be Done?
 The results of a recent study brought two main
issues to the forefront. The first issue is that
people need to know what exactly is invasive.
Many stated if they knew about the invasiveness
of a plant they would not be involved with a
purchase. The second big issue that arose from
the study was that the best way to inform and
educate most people as to what plants are
invasive would be to place a label on the plants
in the nurseries
What Has Been Done?
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Environmental and economic damage continue to
rise because of invasive plants. Though the
United States government has made laws against
importation of species listed in the Federal
Noxious Weed Act (White 2001), there are still
very few restrictions on importation of plants. We
do not have screening for invasive plants before
introduction, though Australia and New Zealand
have already implemented such regulations
(Hoddle 2001). Though President Clinton signed
an executive order for an Invasive Species
Council to be developed, little has still been done
to reduce the harm invasive plants have caused
previously or will cause in the future. Controlling
the distribution of invasive plants has also been
hindered because of the threat of conflict with
international trade agreements (White 2001).
What To Do:
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If all groups involved work together to pool resources
and stand up as a unified front, there will be a better
chance for action. A national plan is needed that includes
development of regulations, education programs, plant
lists, and plant labeling (White 2001). A national plan, if
implemented, will take much gathering of information,
analysis, and cooperation between all involved. There
must be effort to also locate and prosecute those who
intentionally grow, sell, or distribute invasive plants (Kay
2001).
The best thing we can do as a country to prevent further
damage is to start educating our citizens of the dangers
of aquatic plants and their effects on ecosystems around
the world.
References
Hoddle, Mark S. “Restoring Balance: Using Exotic Species to
Control Invasive Exotic Species”. Conservation Biology 18.1.
(2004). 17 Septmber 2006
<http://www.balckwell-synergy .com /links
/doi/10.1111/j.15231739.2004.00249.x/pdf>
 Kay, Stratford H., Steve Hoyle. “Mail Order, the Internet, and
Invasive Aquatic Weeds.” J. Aquat. Plant Manage. 39:88-91 (2001).
14 September 2006
< http://www.apms.org/japm/vol39/v39p88.pdf>
 MacIssac, Hugh J., Robert J. Colautti. “ A Neutral Terminology to
Define ‘Invasive’ Species”. Diversity and Distributions 10, 135141.(2004) 17 September 2006 http://www.blackwellsynergy.com/links/doi/10.1111/j.1366-9516.2004.00061.x/pdf
 White, Peter, Sarah Hayden Reichard. “Horticulture as a Pathway of
Invasive Plant Introductions in the United States”. BioScience
51.2(2001). 17 Septmber 2006
http://www.bioone.org/perlserv/?request=get-document&issn=00063568&volume=51&issue+2&page=103>
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