plant regulation

Boyce Tankersley
Tue, 28 Jul 2009 08:43:11 PDT
I've written and deleted a number of comments/observations on this
subject but I think it may be time to come out of the lurk mode.

The Chicago Botanic Garden has an invasive species committee comprised
of representatives of scientists representing conservation biology,
horticulture and plant collections. We frequently do not agree and have
limited our collective actions with respect to Chicago Botanic Garden to
those areas upon which agreement can be reached. 

I am responding to a very interesting, but ultimately misleading history
of the invasion by kudzu. So forgive me while I put on my professors cap
and share some factoids about invasive plants.

Please understand, quantity of plants planted in proximity (and in)
natural areas has a very strong correlation to a non-native species
ability to adapt to a new environment. In other words, the greater the
number of plants, the higher the likelihood that one or more of them
will posses the adaptive characteristics needed to adapt to a new

The fact that the US government paid for over 2 million plants to be
planted across the South, including abandoned cotton fields that have
evolved into what we call natural areas can not be dismissed as clouding
the water. The USDA Handbook on Woody Plant Propagation lists a number
of current invasive species that were widely recommended for soil
erosion and improvement of wildlife habitat, including the woody
honeysuckles and buckthorn (initially imported by colonists to make

Another factoid from invasive research that is not as widely known as it
should be: less than 1% of non-native plants introduced into the USA
have become invasive.

The last factoid: The financial impact of invasive plant species in
North America have an interesting origin. The original costs were based
upon the ANTICIPATED impact (no data was ever gathered that I am aware
of) of invasion of the Seattle docks district businesses by NORWAY RATS
on a dollars lost per square foot basis. This was extrapolated out to
cover all of the natural areas in the USA, on a square foot basis. Once
I suggested that was not a valid projection the costs associated with
spraying pesticides on agricultural fields (weeds, not invasive plants)
in the Dakotas were used to 'extrapolate' costs across all of the
natural areas in the USA. In other words, if we managed our natural
areas as intensively as farmers do to weed them and if there were as
many weeds. I haven't been to any National Parks in the last year or so,
but last time I visited I don't recall any management practices as
intensive as those used by farmers.

Like Tony Avent, I have also visited with the USDA scientists and other
proponents advocating for a stronger restriction on the importation of
plants. During my conversations the prohibition of importation of
any/all new plants was identified as the desired objective. 

For a less than 1% return on investment, we (the USA) are going to
disrupt a major industry (yes, ornamental horticulture brings in more
revenue than corn and soybeans combined in Illinois) that has a very low
level of success?

Why is there so much pressure to ascribe blame to the ornamental
horticulture industry who will never be in a position to establish
plants next to or in natural areas by the millions without government
support? It appears to be a feel good effort (do something, even if some
facts annoyingly don't support the action).

The problem isn't with new plants coming in. It is with the existing
non-native plants that are in our natural areas. 

Boyce Tankersley
Director of Living Plant Documentation
Co-chair Invasive Species Committee
Chicago Botanic Garden
1000 Lake Cook Road
Glencoe, IL 60022
tel: 847-835-6841
fax: 847-835-1635

"However, I 
think the example of kudzu illustrates the monomania about govt. that 
I believe hinders useful responses rather than facilitating the 
outcome that we all ( hopefully ) might like to see. The truth 
regarding kudzu is somewhat more complex than Tony suggests:
	 " Second, the worst of our invasive plants were researched
and introduced intentionally by the US government (kudzu) ."

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