[APWG] Depauperate native understories, more important that weed or native plant issues?

Thu Jul 29 12:35:16 CDT 2010

Dear Robert and All,

I am living in the most throughly WEED-INFESTED place on the planet, lower
elevation California where our native understory below 1,000 meters is
essentially extinct, having been replaced by over 1,000 species of exotic
plants--So I have to most strongly disagree with your position on exotic
plants, including that I personally call native plants that are
naturalized and out of place, "exotic".

The main problem here in California, is a rapid conversion from the
original perennial native understory---like the bunchgrasses that once
covered the State and held the moisture in the soil in the summer---to a
desert, with an annual understory, with more frequent droughts, higher
summer temps. and changes in the dew point to the point of no measurable
dewfall, more wildland fires, and wetlands drying out---which further
desertifies the State.

The exotics plants may eventually form a solid cover over the land like in
California, and maybe your area gets covered with human-useful weeds like
the wild oats (Avena fatua) covering tens of millions of hectares and
forming the grazing lands of our State, but there also can be a terrible
future ecological effect for the humans, when exotic plants do so.

The big problems world-wide is not necessarily the invasion of the exotic
plants per se, but more importantly, the depauperation of the original
native understory in each country, which opens up bare ground for future
colonization of exotic plants.

See my Photo Vegetation Megatransects from around the world at
http://www.ecoseeds.com/mega.html and see how few places outside of the
far North, where you can find a thriving native understory, and how many
native understories in each country, are in tatters and vulnerable to
future weed invasions?

And there also may be an even bigger issue that trumps the weed and native
plant issues---the general lack of respect for the local native
understories?  See Economic Botany 1976, 30(2): 152-160 The Sacred Groves
of the Western Ghats [India] and see pics at
http://www.ecoseeds.com/wild.2010.html

Sincerely,  Craig Dremann (650) 325-7333

> ________________________________
> From: Robert Layton Beyfuss
> Sent: Thursday, July 29, 2010 10:58 AM
> To: Wayne Tyson
> Subject: RE: [APWG] Science or unfounded rumor?
>
> This exchange ilustrates my issue with "invasion biology" It is
> fundamentally based entirely on xenophobia and not science. It does not
> matter if the plant is performing ecological services as well as or even
> better than native plants, in this case providing food for hummingbirds,
> what matters is the country of origin.

It also does not matter whether or
> not the plant is even invasive or exhibiting weed like characteristics,
> once again it is only the plant's origin that makes it guilty. Its mere
> presence is its guilt.

Is it possible that other factors may be
> contributing to the observed decline of the native species?

It is much
> easier to blame the new arrivals. Where I live in NY there are native
> plant communities that exist in the warmer valleys but are absent from the
> Mountain tops where it is colder. As temperatures rise some of these
> lowland plants may begin to survive at the higher elevations.

Indeed this
> is happening already as has been commonly observed and cited as evidence
> of global climate change. Some of these new arrivals may displace existing
> native plants, some may become weedy but they will never be considered
> invasive because they are native to this general area.

This is xenophobia,
> clear and simple. No one has ever been able to explain or define "native"
> in a way that makes scientific sense. Using the current country of origin
> is meaningless when you consider that countries share borders.

Are
> wildflowers from California ie. the California poppy,  native to the east
> coast where they can become weeds? Should wildflowers from the mid west be
> planted in the medians of highways in NY because they are native while
> exotic plants from Europe are banned because they are exotic?

How exotic
> is exotic? Are plants native to the River valley native to the mountaintop
> five miles away?

Invasion biology has its roots in the science of
> colonization. This is how species come to occupy certain areas. There is
> some very good science here in discovering the dynamics of population
> expansion and decline.

Unfortunately  it has morphed into a witch hunt of
> all things foreign.

I certainly believe in weed science but until
> invasion biology allows for so called native plants to be considered
> invasive, it carries no scientific validity as a science unto itself.
> "unnatural plant communities?"

Indeed. I consider people sitting around in
> offices in Washington or Albany or Portland creating lists of acceptable
> and unacceptable plants, mandating impossible eradication lists and making
> regulations that fly in the face of reality while ignoring what is
> actually occurring in nature as "unnatural".
> ________________________________
> From: apwg-bounces at lists.plantconservation.org
> [apwg-bounces at lists.plantconservation.org] On Behalf Of Wayne Tyson
> [landrest at cox.net]
> Sent: Saturday, July 24, 2010 5:39 PM
> To: apwg at lists.plantconservation.org
> Subject: [APWG] Science or unfounded rumor?
>
> "An interesting phenomenon associated with  foreign plant communities is
> the virtually complete absence of native hummingbird-pollinated plants in
> the areas long dominated by tree tobacco.  Such common natives as purple
> sage Salvia leucophylla, and pitcher sage S. spathacea, California fuchsia
> Zauschneria californica, heartleaved penstemon Keckiella cordifolius, and
> other penstemons are virtually absent from large areas populated by tree
> tobacco in the south coastal valleys and canyons.  Evidently the
> ubiquitous tobacco, with its year round production of yellow flower tubes
> supplying nectar, weans away many of the local hummingbirds from the
> seasonal flowers of native species.  Perhaps other plant species
> "designed" to attract the hummingbird simply do not receive sufficient
> pollination to maintain a local population.  Where tree tobacco is still
> relatively scarce in side canyons, any or all of the normal wild
> hummingbird plant species usually can be found.  (No author listed,
> "Control of the Aliens, Unnatural Plant Communities in the Santa Monica
> Mountains"  FREMONTIA, A Journal of the Native Plant Society  July 1989
> 22-24).
> http://nathistoc.bio.uci.edu/Plants%20of%20Upper%20Newport%20Bay%20%28Robert%20De%20Ruff%29/Solanaceae/Nicotiana%20glauca.htm"
>
> APWG: The preceding statement is specific in its assertions. Is it based
> on evidence or rumor? Where can I find the evidence? In the absence of
> evidence, should I conclude that this statement is solely based upon the
> opinion of the unnamed author, or what? Is conjecture a satisfactory
> foundation for action? Are such unequivocal statements acceptable in
> journals which purport to adhere to scientific standards of publication?
> Should such "information" be propagated through the scientific literature
> if it lacks solid evidence? How does this affect the credibility of the
> issue of alien species in general?
>
> WT
>
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