[APWG] Invaders

[ialm at erols.com]

To further reply, yes it is true that sometimes biological diversity
increases when continents collide, but this takes a minimum of 100,000
years. The Hawaiian island of Kauai is 8 million years old and has much
more diversity than the Big Island of Hawaii which is only 1 million years
old. Do we want to wait that long? 

Richard Leakey wrote the 6th extinction, caused by Homo quasi-sapiens, in
which one of the 5 big asteroid extinctions greatly decreased biological
diversity forever. There was a loss forever of about a dozen fundamental
forms of life out of about 3 dozen. (We are the endoderm/mesoderm/ectoderm
form).  Is the current extinction caused by transport of non-native
species, etc., as bad as the worst natural one? If so limiting movement of
non-native invasive species, followed when necessary by host specific
biological controls such as the weevil for mile-a-minute vine, and early
detection/rapid response such as for wavyleaf basketgrass may keep us under
the threshold so that biological diversity will recover in a million years
rather than never recover. Cheers.

Marc Imlay, PhD

Conservation biologist, Anacostia Watershed Society
(301-699-6204, 301-283-0808)

Board member of the Mid-Atlantic Exotic Pest Plant Council,

Hui o Laka at Kokee State Park, Hawaii

Vice president of the Maryland Native Plant Society,

Chair of the Biodiversity and Habitat Stewardship Committee
for the Maryland Chapter of the Sierra Club. 
 

Original Message:
-----------------
From: ialm at erols.com ialm at erols.com
Date: Sat, 27 Sep 2008 06:51:09 -0400
To: vnps-pot at yahoogroups.com
Subject: Re: [vnps-pot] Friendly Invaders [on non-natives and diversity


In regard to:

"New Zealand is home to 2,065 native plants found nowhere else on Earth.
They range from magnificent towering kauri trees to tiny flowers that
form tightly packed mounds called vegetable sheep.

It sounds like the makings of an ecological disaster: an epidemic of
invasive species that wipes out the delicate native species in its path.
But in a paper published in August in The Proceedings of the National
Academy of Sciences, Dov Sax, an ecologist at Brown University, and Steven
D. Gaines, a marine biologist at the University of California, Santa
Barbara, point out that the invasion has not led to a mass extinction of
native plants. The number of documented extinctions of native New Zealand
plant species is a grand total of three."

How many of these 2062 species in New Zealand are likely extinct but have
not been surveyed for recently over enough of their range to document that
they are extinct?

How many of these 2062 species in New Zealand are not extinct because we
have removed the invasive plant competitors around their habitat? If
invasive plant control is extensive in New Zealand as in Hawaii it may be
dozens or hundreds that we have saved from extinction. Cheers.



Marc Imlay, PhD

Conservation biologist, Anacostia Watershed Society
(301-699-6204, 301-283-0808)

Board member of the Mid-Atlantic Exotic Pest Plant Council,

Hui o Laka at Kokee State Park, Hawaii

Vice president of the Maryland Native Plant Society,

Chair of the Biodiversity and Habitat Stewardship Committee
for the Maryland Chapter of the Sierra Club. 

Original Message:
-----------------
From: Kathi Mestayer kwren at widomaker.com
Date: Fri, 26 Sep 2008 15:02:51 -0400
To: vnps-pot at yahoogroups.com, parmeliamm at aol.com
Subject: Re: [vnps-pot] Friendly Invaders [on non-natives and diversity


So, has there been a rebuttal or response to the NYTimes article?
k


Original Message:
-----------------
From: ialm at erols.com ialm at erols.com
Date: Fri, 26 Sep 2008 07:09:21 -0400
To: apwg at lists.plantconservation.org
Subject: Re: [APWG] Invaders



In regard to:

"New Zealand is home to 2,065 native plants found nowhere else on Earth.
They range from magnificent towering kauri trees to tiny flowers that
form tightly packed mounds called vegetable sheep."


It sounds like the makings of an ecological disaster: an epidemic of
invasive species that wipes out the delicate native species in its
path. But in a paper published in August in The 
<http://topics.nytimes.com/top/reference/timestopics/organizations/p/pr >
oceedings_of_the_national_academy_of_sciences/index.html?inline=nyt-org>
Proceedings of the National Academy of Sciences, Dov Sax, an ecologist at
<http://topics.nytimes.com/top/reference/timestopics/organizations/b/br >
own_university/index.html?inline=nyt-org>Brown University, and Steven D.
Gaines, a marine biologist at the University of California, Santa Barbara,
point out that the invasion has not led to a mass extinction of native
plants. 

The number of documented extinctions of native New Zealand plant species is
a grand total of three."

How many of these 2062 species in New Zealand are likely extinct but have
not been surveyed for recently over enough of their range to document that
they are extinct? 

How many of these 2062 species in New Zealand are not extinct because we
have removed the invasive plant competitors around their habitat? Cheers.

Marc. 
Original Message:
-----------------
From: Marc Imlay ialm at erols.com
Date: Sat, 13 Sep 2008 21:49:38 -0400
To: schenkmj at earthlink.net, apwg at lists.plantconservation.org
Subject: Re: [APWG] Invaders


A Report on the Progress of Invasive Plant Control Program 

 

Maryland Native Plant Society, Anacostia Watershed Society and 

Sierra Club Habitat Stewardship Committee Report 

 

Non-native invasive species of plants such as English Ivy, Japanese
Stiltgrass and Kudzu are covering the natural areas that we in the
conservation movement have worked so hard to protect from habitat
destruction, erosion and water pollution.  Just as we are making progress on
wetlands, stream bank stabilization, and endangered species, these plants
from other parts of the world have typically covered 20-90% of the surface
area of our forests, streams and meadows. Many of us feel demoralized and
powerless to combat these invaders that have few natural herbivores or other
controls. 

 

The Maryland Native Plant Society, Anacostia Watershed Society and Sierra
Club are establishing a program to provide local groups and public and
private landowners with several models to draw upon in the region. We are
assisting in developing a major 5 year work effort at each site to remove
massive populations of about a dozen species. Regular stewardship projects
are conducted in all seasons including winter, early spring, late spring,
summer, and late summer.  This high-intensity program is followed by a
low-intensity annual maintenance program to eliminate plants we have missed,
plants emerging from the seed bank, and occasional plants migrating in from
neighboring areas. We announce regular monthly projects at over 40 sites in
Maryland almost all of which were initially started as a result of
on-the-ground workshops conducted by current MNPS members in Charles County
and Montgomery County. The Nature Conservancy has also conducted projects on
natural areas for many years. MNPS and the Sierra Club sponsor the monthly
projects at Chapman Forest (800 acres), Swann Park (200 acres) and Greenbelt
National Park (1.5 square miles). They co-sponsor Little Paint Branch Park
(150 acres) and Cherry Hill Road Community Park (15 acres) removals in
Beltsville and Magruder Park in Hyattsville MD (15 acres) with the Anacostia
Watershed Society and provide considerable assistance to the other projects.


 

These sites serve as a visible example of what can be accomplished. 

 

The biggest challenge is to ensure that in subsequent years all the
successful projects are carried on by responsible entities. Our advice to
others considering similar projects are to recognize that restoration of our
native ecosystem is realistic but requires an appropriate level of work
effort. 

 

Many of us have done extensive surveys of this area and find that at least
80% of the natural areas are salvageable with a combination of mechanical
and carefully targeted chemical control and no requirement for
re-vegetation. The natives return on their own since they initially covered
the majority of the surface area. We remove all the class 1 and class 2
exotic species, typically 5-20 species, because otherwise if you just
eradicate one exotic another one may replace the one removed. 

 

Our policy is to use carefully targeted, biodegradable herbicides in natural
areas, such as glyphosate and triclopyr, that do not migrate through the
soil to other plants. Instead of spraying invasive trees such as Ailanthus,
Norway Maple, and Chinese Privet we inject concentrated herbicide into the
tree either by basal bark, hack and squirt or cut stump. Seedlings are easy
to hand pull. We wait for wet soil after a rain to hand pull, first
loosening with a garden tool such as a 4 prong spading fork so the center of
the plant rises perceptively. At the 200 acre Swann Park, where we are
essentially in maintenance phase after 5 years, 17 of the 19 non-native
species are eradicated or nearly so. Only Japanese Stiltgrass and Garlic
Mustard remain serious. 

 

All the methods, techniques and/or findings of these projects can be used
where the initial cover of non-native invasive species is less than 30% of
the total plant cover and adequately where under 70% cover. At higher
percent coverage the chemical component is more overwhelming and native
plant re-vegetation may be necessary with native species that are not
cultivars and are obtained from the wild or from nursery stocks originally
collected locally in the wild. There are several well researched species
mixes that include 12-16 herbaceous and shrub species including nitrogen
fixers. 

 

Marc Imlay , PhD Conservation biologist, Anacostia Watershed Society 

301-699-6204, 301-283-0808

Board member of the Mid-Atlantic Exotic Pest Plant Council, 

Hui o Laka at Kokee State Park, Hawaii 

Vice president of the Maryland Native Plant Society, 

Chair of the Biodiversity and Habitat Stewardship Committee 

for the Maryland Chapter of the Sierra Club. 

Remember our five year goal: It is considered standard that such invasive
plant removal projects are normally done throughout the region, the nation,
and the world. 

 




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