[APWG] Maryland, 2007, Report on the Progress of Invasive Plant Control Program RE: Invaders

[Marc Imlay]

Last May it took one person only five 8 hour days to hand remove 

all invasive plants for 100 acres of Swann park. This included all 

specimens of both juvenile and adult garlic mustard.  

 

In response to the point about: 

 

"The Director of our local Nature Conservancy told me that he could 

spend 90% of his entire budget for the next three years, attempting to 

eradicate roadside garlic mustard with the only certain outcome that 

he would have to start all over again in 3 years." 

 

He would not have to start over in three years if he spent about 10 % 

of his budget in year 4, about 5 % in year 5 and about 2 % in year 6. 

Garlic mustard in Swann Park was originally overwhelming in 2001. 

 

 

A Report on the Progress of Invasive Plant Control Program, 2007 

 

Maryland Native Plant Society, Anacostia Watershed Society and 

Maryland Chapter of the Sierra Club Habitat Stewardship Committee 

 

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 60 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 7 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. 

 

 

 

-----Original Message-----
From: apwg-bounces at lists.plantconservation.org
[mailto:apwg-bounces at lists.plantconservation.org] On Behalf Of Bob Beyfuss
Sent: Friday, September 12, 2008 10:15 AM
To: Michael Schenk; apwg at lists.plantconservation.org
Subject: Re: [APWG] Invaders

 

Hi All

There is no question that globalization has dramatically accelerated the 

spread of invasive species but I really do not see any possibility at all 

of that situation changing in the future. In fact, it is likely to become 

much worse in the next few decades. The question that arises, is how do we 

react?  I don't think that simply declaring "war" on all invasive species 

anywhere they occur and at whatever rate of infestation is the answer. The 

older I get, the less convinced I am that war is the answer for most of our 

problems.  I would prefer a more thoughtful approach targeting protection 

of specific and highly sensitive ecosystems instead of ill advised 

eradication programs that are doomed to failure before they begin. The 

Director of our local Nature Conservancy told me that he could spend 90% of 

his entire budget for the next three years, attempting to eradicate 

roadside garlic mustard with the only certain outcome that he would have to 

start all over again in 3 years. When I see eradication programs conducted 

in highly disturbed urban environments I wonder if the cost justifies the 

temporary results. Ultimately, the disturbances that led to the invasions 

remain and often the results of widespread herbicide applications only 

insure that the problem. Unless the entity that is applying any herbicide 

against invasives can reasonably predict that the outcome of that 

application will result in the desired reestablishment of the plant 

community it is designed to protect, I question the action. In simple 

terms, killing invasive plants simply because "they are there" with no real 

clue as to what will follow, is bad policy.

Bob

 

 

At 11:49 AM 9/11/2008, Michael Schenk wrote:

Bob, thanks for the article.

 

 

This article contains an excellent summary of the unprecedented threat of 

the modern spread of invasive species: the vastly accelerated rate of 

invasion, coupled with the stress placed on ecosystems by induced rapid 

changes. Read through to the latter part, past the feel-good stuff about 

the fossil record. Of course the fossil record doesn't contain anything 

comparable. There was no highly mobile technological species imposing 

geological rates of change in decades as opposed to millions of years.

 

Change in species diversity and ranges happens constantly. It's the rate 

of change which is worrisome. The rate of change from a major asteroid 

strike, scaled in weeks or years, is more similar to the current rate of 

change than the megayears we'll find in the fossil record.

 

Mike

 

 

Message: 1

Date: Wed, 10 Sep 2008 14:53:13 -0400

From: Bob Beyfuss <rlb14 at cornell.edu>

Subject: [APWG] Fwd: Friendly Invaders

To: apwg at lists.plantconservation.org

Message-ID:

6.2.1.2.2.20080910145256.051d6008 at postoffice8.mail.cornell.edu>

Content-Type: text/plain; charset="iso-8859-1"

 

 

 

 

X-Mailer: QUALCOMM Windows Eudora Version 6.2.5.6

Date: Tue, 09 Sep 2008 08:57:20 -0400

NY Times

September 9, 2008

Friendly Invaders

By 

http://query.nytimes.com/search/query?ppds=bylL&v1=CARL >>>ZIMMER&fdq=199 

60101&td=sysdate&sort=newest&ac=CARL

ZIMMER&inline=nyt-per>CARL ZIMMER

 

 

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.

 

 

When Europeans began arriving in New Zealand, they brought with them

alien plants ? crops, garden plants and stowaway weeds. Today, 22,000

non-native plants grow in New Zealand. Most of them can survive only with

the loving care of gardeners and farmers. But 2,069 have become

naturalized: they have spread out across the islands on their own. There

are more naturalized invasive plant species in New Zealand than native 

species.

 

 

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

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.plantconservation.org/pipermail/apwg_lists.plantconservation.org/attachments/20080913/5b98316b/attachment.html>