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Global Invasive Species Team listserve digest #126
Fri Apr 16 2004 - 17:04:17 PDT
--CONTENTS--
1. Web site additions (Global, Planet Earth)
2. A good resource for info on fire and weeds (Global, Planet Earth)
3. Aridlands Grazing Network Workshop #6 (Western North America)
4. Weedy gifts! (Washington, USA)
5. Japanese barberry control (Global, Planet Earth)
6. Literature reviews (Global, Planet Earth)
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1. Web site additions (Global, Planet Earth)
From: Barry Rice (bamrice(at)ucdavis.edu)
One of the best indicators that a non-native plant is likely to be
invasive is if it has a history of being invasive someplace else. The WIST
web site is now hosting a big listing of weedy records, created by our
Australian colleague Rod Randall. Curious if that Bongardia chrysogonum or
Carnegia gigantea in your area has been a weed for someone else? Look it
up on Rod's list to see if the plant has a record of prior offenses:
http://tncinvasives.ucdavis.edu/biglist.html
We've also included an update on the summer and fall invasive species
meetings that are being scheduled. Perhaps a holiday in Alabama is in
order, so you could attend the Alabama Invasive Plant Council too!
http://tncinvasives.ucdavis.edu/meetings.html
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2. A good resource for info on fire and weeds (Global, Planet Earth)
From: Mandy Tu (imtu(at)tnc.org)
If you are a prescribed fire nut, you are probably already well-aware of
the US Forest Service's Fire Effects Information Systems database and
website, chock-full of useful information on the effects of fire on
specific plants, on vegetation types, and on wildlife (including mammals,
birds, amphibians, and reptiles). Did you know that they now have
extensive write-ups on fire effects and the fire ecology for a number of
invasive plant species? These write-ups also include information on
species distribution, potential habitats in which they occur, and
management considerations. We (at WIST) have been working with the FEIS
folks to complete these Knowledge Base Summaries (KBS) for 60 invasive
plant species. See completed summaries at:
http://www.fs.fed.us/database/feis/index.html
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3. Aridlands Grazing Network Workshop #6 (Western North America)
From: Bob Unnasch (bunnasch(at)tnc.org)
The Aridlands Grazing/Invasive species management meeting will be 18-20
May 2004, and will be held at Hell's Gate State Park in Lewiston, Idaho.
As a field trip, we will be taking a jet-boat up the Snake River to visit
Tri-State CWMA sites in Hell's Canyon on the 18th! Expect to learn and
have fun!
The registration form, which includes a workshop description) can be
downloaded from the WIST web site at:
http://tncinvasives.ucdavis.edu/meetings/18052004.doc
The registration form must be completed and emailed back to me by 30
April. The registration form includes logistical information that is
important for you to review. While we have reserved a block of rooms a the
Quality Inn in Clarkston, WA, YOU NEED TO MAKE YOUR OWN HOTEL
RESERVATIONS. Instructions are in the registration packet. The Conference
organizers are paying for the conference expenses, including rooming for
the nights of the 17th, 18th & 19th. We ask you to find a roommate and
share a room if at all possible. We can help provide names of potential
roommates.
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4. Weedy gifts! (Washington, USA)
From: Betsy Lyons (blyons(at)tnc.org)
---Betsy informed us of a great web site that is your "answer to birthday
gift buying, employee appreciation, xmas and marketing...." Where else can
you get a Japanese knotweed baby-bib?
http://www.cafeshops.com/cp/store.aspx?s=InvasiveSpecies
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5. Japanese barberry control (Global, Planet Earth)
From: Graham Rice (garden(at)tiscali.co.uk)
Can anyone point me to some detailed recommendations on chemical control
of Japanese barberry (Berberis thunbergii)? I've done a fairly thorough
web search and found a variety of generally vague and contradictory
recommendations. Have any studies been done on this? Is the cut-stump
method more effective then a foliar spray? Are there any recommendations
on exact timing?
In particular, I find that cut-stump treatments are recommended "from mid
summer to fall", "when the ground is frozen", "when the ground is not
frozen" and "at any time of year"!
I have my own views on this but any pointers to research or to detailed
recommendations for any form of chemical control would be much
appreciated.
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6. Literature reviews (Global, Planet Earth)
From: John Randall (jarandall(at)ucdavis.edu)
Hall, R.O., Jr., J.L. Tank and M.F. Dybdahl. 2003. Exotic snails
dominate nitrogen and carbon cycling in a highly productive stream.
Frontiers in Ecology 1(8): 407-411.
The New Zealand mud snail, Potamopyrgus antipodarum, has invaded many
waterways in the western U.S. since it was first detected here in 1987.
This study found that it dominated nitrogen and carbon fluxes in a
geothermal spring stream in the greater Yellowstone area. These non-native
invasive snails (native to New Zealand) consumed 75% of gross primary
production in the stream and accounted for two-thirds of ammonium
demand. This was due to the high snail biomass (densities of 20,000 -
50,000 snails/m2), rather than to high rates of consumption and
excretion. These impacts are like those caused by zebra mussel, another
instance in which a single species achieves such high biomass that it can
dominate nutrient fluxes; for example in some lakes zebra mussels can
filter volumes of water equal to the entire water column in 1-4 days.
These species may also affect processes beyond the ecosystems they
infest by altering nutrient exports to downstream systems. Unfortunately,
New Zealand mud snails are continuing to spread to watersheds across
western North America including the Columbia, Snake, Missouri, and
Colorado watersheds and in October, 2003 they were found west of the
Sierra Nevada-Cascade Range for the first time in a popular fishing area
of Putah Creek west of Davis, California. Two months later they were
found in California's Mokelumne River and in January 2004 a well
established population was discovered in an eleven mile reach of
California's Calaveras River.
Ayres, D.R. and D.R. Strong. 2003. Spartina foliosa (Poaceae) - a common
species on the road to rarity? Madrono 50(3): 209-213.
Spartina foliosa, a saltmarsh cordgrass native to the US Pacific coast,
is forming hybrid swarms with S. alterniflora, a cordgrass from the
Atlantic and Gulf coasts, and that was introduced to San Francisco Bay in
the 1970s. Initially researchers believed that hybridization between pure
parents of each species was the driving force of the hybrid spread but
they subsequently found no F1s among hybrids in the wild and realized that
there was little overlap between flowering times of the two species. They
now believe that hybridization between pure parents is relatively rare and
that instead the few hybrids which do form have broad flowering times
which overlap those of both species and allow high levels of
backcrossing. Previously it was believed that hybridization was not a
major threat to common, wide ranging species like S. foliosa, but the
rapid increase in abundance of hybrids in San Francisco Bay and adjacent
areas suggests it may be in this case. Models of the population dynamics
of the two pure Spartina species and the hybrids using relative fitness
values based on their field data, predicted that both pure species will be
replaced by a hybrid swarm in an invaded population within 20
generations.
The authors conclude that S. foliosa is in immediate danger of
extirpation in San Francisco Bay, and perhaps beyond.
Boydston, R.A. and M.M. Williams, II. 2004. Combined effects of Aceria
malherbae and herbicides on field bindweed (Convolvulus arvensis) growth.
Weed Science 52: 297-301.
Combining the biocontrol agent Aceria malherbae (a gall mite) and a
sublethal dose of the herbicide 2,4-D or glyphosate (active ingredient in
Roundup and Rodeo) reduced field bindweed root biomass more than either
treatment alone. These results are fairly typical for a recent series of
studies on combining the use of herbicides with biocontrol agents (usually
agents that have not satisfactorily suppressed the weed on their own)
[e.g. Lym and Nelson 2002 Weed Science 50: 812-819; summarized in
listserve digest 112).