Land Preservation Tool Kit

Citizens across Maryland frequently observe a new or ongoing threat to their forests and other natural areas. Their neighboring woods or stream is often being destroyed. The Sierra Club receives enquiries at to what the citizens can do to stop or reduce the destruction of their favorite woods, meadows, wetlands or creeks. The Sierra Club Activist Tool Kit has been prepared to provide citizens with a wide variety of tools that have assisted us successfully across the state. The regional examples and case histories are models of comparable programs across the State of Maryland. For instance, examples are provided for Transfer Development Rights in Montgomery, Charles and Calvert Counties which varies in effectiveness across the State.

One of the most successful approaches has been to save an area before it is owned by developers. One of the most common and unnecessary causes of transfer of natural areas to development has been lack of awareness that there are many ways to reduce property taxes to affordable levels. This is particularly important when descendents receive land their parents wanted to preserve but have difficulty in paying the inheritance and property taxes.

After developers own the land, natural areas recognized for their high quality have been purchased by organizations such as The Nature Conservancy and The Trust for Public Lands and by the State of Maryland as Program Open Space. We have more successfully reduced, rather than stopped, the impact of development elsewhere. When citizens investigate actual adherence to regulations they greatly increase compliance with the law. A dramatic example has been citizens reporting inadequate placement of silt fences to prevent sedimentation from entering our water ways. Maryland Department of the Environment (MDE) officials typically investigate in a few hours and the developer corrects the problem in the same day.

Threats to natural areas not being developed include deforestation, invasion by non-native invasive species such as Kudzu, water and air pollution, erosion, storm water and sedimentation.

Tool Kit


Conservation Easements

Conservancy for Charles County (see web site). An excellent article on conservation easements and donations of natural areas appears in the Spring 2007, issue of NATURE CONSERVANCY vol. 57 No. 1. on page 16: "LAWS FOR THE LAND, New Federal Tax Law helps Families Preserve Their Properties."

Reference the website of the Maryland Environmental Trust, to whom a conservation easement can provide an additional tax break and which lists contact information for local land trusts such as the Charles County Conservancy throughout the State.


A perpetual conservation easement is a legally binding agreement between a landowner and a land trust or a government agency that prevents development from taking place on the property in order to provide permanent protection for its conservation values, especially its natural resources. In a conservation easement — which is perpetual — the landowner voluntarily donates (or sells) certain rights associated with the property, typically the right to subdivide. The easement deed may also include other restrictions designed to keep the property in as natural a state as possible, for example, barring commercial activities on it and requiring maintenance of forested areas and vegetative buffers along streams. Each such easement deed is tailormade to suit the particular property and the landowner’s needs and is recorded with the deed to the property.

The donor of a perpetual conservation easement may be eligible for charitable tax benefits in compliance with IRS rules, inasmuch as private land conservation is deemed to benefit the public. Under these rules, the easement needs to satisfy one or more of the following criteria:

  • It preserves an important natural habitat or ecosystem.
  • It maintains an historically important land area or building.
  • It results in a significant public benefit by preserving open space (including farmland and forested land) for the scenic enjoyment of the general public or pursuant to a clear governmental policy.
  • The land will be used for public outdoor recreation or education.

One advantage of the conservation easement is that the property remains in private ownership and can be conveyed to successor owners through bequest or sale. Because it is perpetual, its provisions apply to all future owners. The holder or grantee of a conservation easement is legally obligated to monitor the ongoing observance of the restrictions. This stewardship task is taken seriously by land trusts, which operate programs for maintaining contact with the landowners and arranging periodic property inspections. In the event of a breach of the easement’s requirements, the land trust is entitled to take legal action to remedy the problem in the event the landowner does not comply voluntarily. Such problems are rare. Throughout Maryland and the entire country, perpetual conservation easements are the preservation tool of choice for nonprofit land trusts and have resulted in the permanent protection of millions of acres of environmentally and culturally valuable land. The benefits include protection of water quality in streams, the preservation of essential wetlands, the safeguarding of forests, and assurance of good habitat for wildlife and native plants. They also achieve keeping open space open and play a key role in the protection of landscapes that historically define a community or region. And, because they are perpetual, their benefits will be enjoyed by generations to come. Local land trusts are found in every Maryland county. A current list of them can be found on the websites of both the Maryland Environmental Trust (MET) and the national Land Trust Alliance (LTA). MET is a statewide land trust housed within the Maryland Department of Natural Resources. Most local land trusts and MET work cooperatively to carry out conservation easement work.

(Text prepared by Vivian Mills, Conservancy for Charles County, January 2008)

Return to Table of Contents

Program Open Space

Consult and to see if a natural area you propose to be purchased is already recognized as a priority area. If it is not, conduct a survey with biologists for high quality natural features including wetlands. Offer to compensate the biologists if possible since many of these individuals, while often volunteering, are swamped with such requests. Compensation will enable the field of available experts to expand for all the citizens of Maryland.

See to pursue the application process with local government agencies.

Return to Table of Contents

Forest Conservation Plans

Forest Stewardship Plans Offer Landowners Tax Breaks—and More

Landowners, do you want to preserve your land or restore it to its natural state for future generations? For doing this, you can get financial assistance, including a property tax reduction on your land, assessed on its value set at about $150 per acre. The current value depends on the current market based assessment.

Here’s the catch: Working with a state forester, you must develop a Forest Stewardship Plan, and the Maryland Department of Natural Resources (DNR) must approve it. After DNR approves the plan, you become part of the Maryland forest stewardship program. All aspects of forest resource management are considered by DNR, and—the good news is that you do not have to harvest trees. Some plans, for example, consist entirely of removing non-native invasive plants.

Another option is submitting a forest management plan to the State Tax office which will give the landowner a tax reduced assessment called the forest management agreement. The assessment is about $50 per acre higher. The landowner doesn't have to pay any fees for entering either.

For either program there are inspections required too, every 5 years for the FCMA and every 3 years for the Forest Management Agreement.

The options offered by DNR for forest resource management include fish and wildlife, natural heritage and recreation, soil and water, and forest products. The natural heritage and recreation aspect, for example, focuses upon restoration of mature old growth with natural biodiversity and resulting ecosystem services (such as water retention) to prevent downstream flooding, crown-fire control, and climate-change mitigation.

Expert Help Required

The stewardship program has a few eligibility requirements, but the most critical consideration is to select a forester trained in ecosystem management and conservation biology to include alien invasive species control, fragmentation theory, herbaceous plants, endangered species, and non-game biology. Most foresters who write plans are trained primarily in forest products. Your forester should be primarily trained in ecology and be supportive of your values.

Here’s what DNR has to say about the topic ( "Any owner of 5 or more contiguous acres of forest land may enter the Forest Conservation and Management Program. …the forester, with assistance from other natural resource professionals, must match the objectives of the owner to the biological requirements of the forest. Your acceptance in the Forest Conservation and Management Program will depend upon the specific prescription of stewardship practices… You must have your forest stewardship plan prepared by a registered professional forester [state, private, consulting, or industrial] and approved by the Director of the Forest Service. The plan must contain a detailed schedule of practices to be accomplished and their completion date."

The Tax Break

Landowners also can obtain a Forest Conservation Management Agreement (FCMA) through the Maryland Department of Assessments and Taxation. DNR describes it as “a legal agreement recorded in land records, binding for fifteen years, and renewable for a minimum of five years.”

With an FCMA, the landowner can add or delete acreage, add or delete owners, and sell all or part of the parcel. In return, says DNR, “the property is assessed at $125/acre regardless of its location in Maryland. The assessment is frozen at that level for the fifteen years of the agreement. The FCMA involves fees for developing the management plan, entering the program, and periodic inspections.”

For more information on this topic, go to

The following foresters and advocates have prepared, or indicated their interest in, Forest Stewardship Plans for removing non-native invasive plants.

Bud Reaves, Licensed Forester # 336
Maryland Licensed Tree Expert # 1042
Pesticide Consultant #28207-19930
Woodland Management Services LLC
26 Brookfield Road
Pasadena, MD 21122

Peter Perry

Len Wrabel
Mar-Len Environmental

Steven W. Koehn, Director / State Forester Maryland DNR Forest Service
Tawes State Office Building, E-1 580 Taylor Avenue Annapolis, Maryland  21401
Work     (410) 260-8501
Mobile   (410) 370-0427
Fax       (410) 260-8595

Phil Pannil 301-791-4010

Dave Gailey  301-880-2746
Southern Maryland Regional Forester, DNR

Jane Wolfson
Towson University

Paul Eriksson
Watershed forester
Maryland DNR Forest Service,

George Eberling

H. Stacy Miller
Registered Forester
8903 Flagstone Circle Randallstown, MD 21133Bus. Phone: 410-922-
Bus. Phone: 410-922-7476
Home Phone: 410-922-7476

Richard F. Masse
Registered Forester
Richard F. Masse, R.P.F
Natural Resources Staff Officer
3500 Faichet Avenue
Andrews Air Force Base, MD 20331-5157
Phone: 301-836-8882

Donald Marquardt
339 Chalet Drive
Millersville, MD 21108
Home Phone: (410) 987-11248

Return to Table of Contents

Endangered Species Tool Kit

To determine if an endangered species may occur in your natural area of concern there are regulatory and non regulatory lists. They are both valuable for legal, geographic and scientific support.  Determine if any listed species are indicated for your county or are in the species range that county lies in  The species should be carefully surveyed for during the appropriate season for identification because most studies are inadequate in this respect. Reports by a developer or agency that a species is not known from the site is frequently because surveys have not been conducted. As an example of the distinction between scientific lists and regulatory lists, only about 2% of the cave species in the United States are listed by the federal government as endangered or threatened. The Nature Conservancy has determined that 95% are actually imperiled. In many cases a single event such as one chemical spill from a nearby highway can wipe out an entire species such as blind salamanders, cavesnails and crayfish. Sewage, pesticides, heavy metals, and fertilizers wash into sinkholes, and karst is destroyed directly by roads, quarries, and construction of buildings.

See and for the state endangered species act which is supported by Code of Maryland Regulations 08.03.08 and the official State Threatened and Endangered Species list as well as species occurring in Maryland that are listed as candidates for listing on the Federal list of Endangered Species list, and additional species.

Following is an excellent scientific list,

In addition, is a useful but incomplete indicator of geographic locations.

Contact information for individual natural heritage programs is available at

NatureServe Conservation Status

Determining which plants and animals are thriving and which are rare or declining is crucial for targeting conservation towards those species and habitats in greatest need. NatureServe and its natural heritage member programs have developed a consistent method for evaluating the relative imperilment of both species and ecological communities. These assessments lead to the designation of a conservation status rank. For plant and animal species these ranks provide an estimate of extinction risk, while for ecological communities they provide an estimate of the risk of elimination.

Conservation status ranks are based on a one to five scale, ranging from critically imperiled (G1) to demonstrably secure (G5). Status is assessed and documented at three distinct geographic scales-global (G), national (N), and state/province (S). These status assessments are based on the best available information, and consider a variety of factors such as abundance, distribution, population trends, and threats.

Interpreting NatureServe Conservation Status Ranks

Although most subnational conservation status ranks do not change frequently, the most current S-ranks can be obtained directly from the relevant local natural heritage program (contact information available at

Status Assessment Criteria

Use of standard criteria and rank definitions makes NatureServe conservation status ranks comparable across organism types and political boundaries. Thus, G1 has the same basic meaning whether applied to a salamander, a moss species, or a forest community. Similarly, an S1 has the same meaning whether applied to a species or community in Manitoba, Minnesota, or Mississippi. This standardization in turn allows NatureServe scientists to use the subnational ranks assigned by local natural heritage programs to help determine and refine global conservation status ranks.

For ecological communities, the association level generally is the classification unit assessed and ranked (see Classification of Ecological Communities for an explanation of the classification hierarchy). Only global conservation status ranks are currently available for ecological communities on NatureServe Explorer.

Relationship to Other Status Designations

NatureServe conservation status ranks are a valuable complement to legal status designations assigned by government agencies such as the U.S. Fish and Wildlife Service and the National Marine Fisheries Service in administering the U.S. Endangered Species Act (ESA), and the Canadian Wildlife Service in administering the Species at Risk Act (SARA). NatureServe status ranks, and the documentation that support them, are often used by such agencies in making official determinations, particularly in the identification of candidates for legal protection. Because NatureServe assessment procedures-and subsequent lists of imperiled and vulnerable species-have different criteria, evidence requirements, purposes, and taxonomic coverage than official lists of endangered and threatened species, they do not necessarily coincide.

The IUCN Red List of threatened species is similar in concept to NatureServe's global conservation status assessments. Due to the independent development of these two systems, however, minor differences exist in their respective criteria and implementation. Recent studies indicate that when applied by experienced assessors using comparable information, the outputs from the two systems are generally concordant. NatureServe is an active participant in the IUCN Red List Programme, and in the region covered by NatureServe Explorer, NatureServe status ranks and their underlying documentation often form a basis for Red List threat assessments.

Species is known to occur in this nation or state/province. Contact the relevant natural heritage program for assigned conservation status. Contact information for individual natural heritage programs is available at

Return to Table of Contents

Wetland Surveys for Compliance with Sections 401 and 404 of the Clean Water Act

To stop development we delineate obligate and facultative wetland plants.  SOS (Save Our Streams) and Audbon Naturalist Society offers courses.  April-May is the best time to identify species. Obligate wetland plants are found in wetlands 99% of the time and Facultative wetland plants are found in wetlands 67-99% of the time. The Maryland Department of the Environment lists wetland plant species at We have generally found that projects were proceeding forward in violation of the Clean Water Act without valid permits until we actually got meaningful surveys conducted. Our first victory in saving Chapman Forest was a survey that showed that the proposed golf course would have violated the Clean Water Act for wetlands and it was then denied.   

Return to Table of Contents

Establish and Maintain Greenways to Avoid Fragmentation

Example for the Mattawoman Watershed in Prince Georges and Charles Counties. Testimony on the Cross County Connector Extension proposal.

The critical importance of preventing habitat fragmentation by maintaining greenways is now widely documented and understood. Living forms native to the area, both animals and plants, depend on the availability of sufficient space and food sources and shifting locations of habitat and food sources in order to be able to thrive and even to survive. Natural areas on opposite sides of Billingsley Road and on the proposed route north of Billingsley Road as shown on the attached map represent a cumulatively significant contribution in this regard, not only because the road is presently relatively narrow in width between these natural areas of significant size, but also because of their proximity to other publicly held areas in western Charles County that have been restricted from development, including the Mattawoman Wildlands and the Mattawoman Natural Area.

General management principles include providing wildlife migration corridors for re-colonization between natural areas following local extirpation due to seasonal, man-made, or climatic stresses. Stresses include natural disturbances such as the mosaic pattern of storm events, drought, diseases, fire, competitors, predators, prey, succession, floods and seepages. Some populations of plants and animals are "sources" of individuals which migrate out and replenish other populations known as "sinks". In addition, sufficient space is needed for large animals with large home ranges.

For example, in the general region proposed for the Cross County Connector Extension spotted salamanders utilize vernal pools and ponds that are temporary over time. Many semi-aquatic insects, salamanders, frogs, snakes and turtles utilize aquatic and terrestrial habitats in their life cycle. The buffer zone for 95% of a population of salamanders would extend 534 feet from the wetland edge into the closed canopy terrestrial habitat.

The maximum corridor width which most birds and many mammals, plants and invertebrates cross roads sufficiently to reproduce and maintain populations is two lanes. The proposal to widen the road as a cross county connector and build a 4 lane northern road has a cumulative impact which requires being addressed in an Environmental Impact Statement. Section A and B harbor high quality natural areas. I saw a dead raccoon road kill at Section C today, April 26, 2005. Sections E and F have some legal protections as Waters of the State and Wetlands of Special Concern. However, all environmental impacts including terrestrial, as well as aquatic, are legally required to be studied in the environmental impact studies, not just those requiring actual environmental protection or mitigation. Fully informed decision making is required by law. About half of Section G has high quality natural area on both sides of Billingsley Road and two thirds of Section H.

A forest reserve primarily requires protection of the forest interior for birds including the area sensitive species and wide ranging species such as raptors. 6,000 acres may be the minimum that supports all forest breeding species in the Mid-Atlantic. This roughly includes Chapman Forest and the contiguous Mattawoman Natural Area, Wildlands, etc.

"The Mattawoman is forty times more productive of anadromous fish than the seven other Chesapeake tributaries repeatedly monitored by DNR" including blueback and alewife herring in Chapman Forest. Lack of, or inadequate culvert placements at stream crossings block fish passage and isolate them from runs.

The proposed solution to fragmentation is to maintain and establish greenways between natural areas and to maintain corridors such as roads and trails as narrow as feasible. Native plant vegetative covers along roads would follow the guidance found in "Roadside Use of Native Plants", Bonnie Harper-Lore, et al, Federal Highway Administration.

Marc Imlay, PhD
Board member of the Mid-Atlantic Exotic Pest Plant Council,
Vice president of the Maryland Native Plant Society,
Chair of the Biodiversity and Habitat Stewardship Committee for the Maryland Chapter of the Sierra Club.

Return to Table of Contents

Programs to reduce impact of development

What do most citizens do when their neighborhood or environment is threatened by a development project?

Many react by hiring a lawyer.

Yet studies just completed by CEDS show that this is seldom the best first step. The reason is that most citizens resolve their concerns through a negotiated agreement with the developer or regulatory officials; not by stopping a project. The key to a successful negotiation lies in identifying reliable ways of resolving citizen concerns that allow the applicant to get most of what they want. Few attorneys have the technical expertise to identify these equitable solutions.

A new CEDS factsheet, Strategies for Winning Land Development Battles, describes how citizens can dramatically increase their rate of success while greatly reducing lawyer and expert witness fees. The factsheet is posted at the top of the left-hand column of the CEDS website at

CEDS research shows that only 1% of all contested development projects are stopped. In those cases where excessive impacts cannot be designed away, a lawyer is frequently critical. Yet not all attorneys are equally equipped to represent citizens in these disputes. However, CEDS can help here too through our nationwide network of 135 attorneys who specialize in representing citizens in land use, zoning, and environmental cases.

I would deeply appreciate it if you would consider mentioning the factsheet to citizens who contact your group about a development issue.

To see an example of one of the CEDS studies referenced above visit: Citizens Perspective on the Baltimore County Development Review Process.pdf

Richard D. Klein
Community & Environmental Defense Services
811 Crystal Palace Court
Owings Mills, Maryland 21117
410-654-3028 Fax
443-421-5964 Mobile
Web Page:

Return to Table of Contents

Certification by the Forest Stewardship Council program (FSC) is a good regional example of carrying out a Forest Stewardship Council certification program.

Maryland Native Plant Society
P.O. Box 4877
Silver Spring, Maryland 20914

February 14, 2007

The Honorable Martin O'Malley
Office of the Governor
State of Maryland
100 State Circle
Annapolis, Maryland 21401-1925

Dear Governor O'Malley,

The mission of the Maryland Native Plant Society is to increase awareness and appreciation of native plants and their habitats, leading to their conservation and restoration. We are contacting you about measures that the State of Maryland can undertake to conserve public lands and natural resources.

We want to encourage the State to manage public lands in a way that benefits both the public and the natural resources contained on those lands. Projects that alter public lands, such as road-building or logging, may remove native plants, allow the encroachment of invasive species, degrade the streams and remove wildlife habitat. Before alterations to public lands are made, analysis of loss of forest "services" should be conducted, and the public should have an opportunity to participate in decisions that affect public lands.

If after analysis and public input, it is determined that logging public lands is in the best interests of the public and forest management, logging should take place only after certification by the Forest Stewardship Council program (FSC). This certification program is supported and approved by major environmental organizations. The Sustainable Forest Initiative (SFI) is another certification program controlled primarily by the forest industry and, in our judgment, should not be used as a valid alternative for certification.

We would encourage the passage of legislation to change the practice of the Department of Natural Resources' retention of revenues from logging contracts. The current situation constitutes a conflict of interest for an agency that is supposed to protect natural resources.

The Maryland Native Plant Society has a particular interest in old growth forests in Maryland. DNR has already inventoried these rare areas, and they should be designated Wildlands to permanently protect them.

Finally, we have been encouraged by the adoption of Green Infrastructure Master Plans in Prince George's and Anne Arundel Counties, and would like all of the counties to follow suit. A Green Infrastructure Master Plan gives guidance to county planning and zoning departments so that important ecological areas will be protected from development. Anything the State can do to support local Green Infrastructure plans would be welcome.

We look forward to a partnership with the State of Maryland in better protecting the natural resources found on public lands in our State.


Cris Fleming, President
Maryland Native Plant Society

Return to Table of Contents

Non-native invasive species control

Maryland Native Plant Society, Anacostia Watershed Society and Sierra Club Habitat Stewardship Committee Report for 2006

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 work effort (three to five years) 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.

Attachment A announces 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. MNPS with Montgomery County and Prince Georges County MNCPPC, Sierra Club and Anacostia Watershed Society developed signs, announcements, flyers, safety and plant identification handouts, sign in sheets and evaluation forms (attachment B).  A summary of AWS generated invasive plant control progress in 2006 (attachment C) is in chronological order where AWS engaged a total of 1082 volunteers at 12 selected parks including one native plant restoration site. Swann Park had 99 volunteers and Chapman Forest had 78 volunteers.

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. Attachment D.

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. Attachment E summarizes the status of native plant restoration at Woodworth Park.

Over 120 professionals and volunteers participated in The Demolition Derby Field Session of the WEED BUSTERS Invasive Plant Workshop at Frelinghuysen Arboretum, Morristown, New Jersey, August 9, 2006 which provided practical experience with sites where it is best to use mechanical control and sites where it is efficacious to employ chemical control of Japanese Stiltgrass, Wineberry, Garlic Mustard, Oriental Bittersweet, Multiflora Rose, Japanese Barberry, And Tree of Heaven.

Other invasive species include Porcelain-berry, Mile-a-Minute and Japanese Knotweed. My presentation was How Our Monthly Invasive Plant Removal Project Restored Habitats in 40+ Maryland Sites”. This non-native invasive plant removal reaches maintenance phase following major work efforts at each site through a 5 year long combination of mechanical and carefully targeted chemical control.

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.

Thanks again everyone! Marc

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.

Here are my personal notes I used for my talk at the American Chemical Society Synposium in 2005 at the DC Convention Center. My abstract can be found on the ACS website,; search for Picogram, the official publication of the Division, and on pages 48 and 49 is the program schedule for the symposium. My talk was well received.


Many thousands of groups across the Nation are rescuing native plants and animals from non-native invasive species that have no biological control. A typical park is 50-500 acres and has over a thousand species of native plants let alone the thousands of native animal species that depend upon them prior to being covered by monocultures of 5-10 alien species. I have worked with over a hundred of these groups from Hawaii to Maryland and have dedicated my semi-retirement years to helping these groups succeed.

Since this is a chemical society I will focus on integrated pest management. Herbicides are a necessary component of winning the battle.

AWS position paper

I have seen herbicides used when mechanical control is far preferable, both to avoid collateral damage as well as to save time and money. Just as frequently I have seen mechanical control used when chemical control is far preferable. The reason for this has to do with psychology. It is human nature to use whatever tool is available. For example in controlling Japanese Stiltgrass, which is the most serious invasive in the Mid-Atlantic region having covered 10% of New Jersey already, I have been with a group of 8 people earning 10-40 $/hour come across a 15’-20’ patch with virtually no native plants left unable to stop themselves and spent an hour removing it.

If I had on my backpack sprayer I would have finished it in 5 minutes. Contra wise I have caught myself with my back pack sprayer on spraying Japanese Stiltgrass walking over to two or three plants mixed with natives and spraying. It takes one second to remove a single pioneer plant, say 2’ tall and 3’ wide , but several seconds to spray the surface adequately. Consequently at Swann Park in Charles County, Greenbelt National Park, and Little Paint Branch Park in Beltsville in Maryland, we have had separate days for hand removal with volunteers and spray days for staff. The combination works well whether the spray day is first and only thick patches are sprayed leaving the low density areas for volunteers, or volunteers leaving the patches for staff later.

As an example, the North Chevy Chase Christian Church stopped at a terrible patch with hundreds of small closely packed plants, in Little Paint Branch Park and said “we can’t do this”. I agreed and three of us sprayed it 2 weeks later.

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. Then we make a pile rather than bag English Ivy, Wineberry or Multiflora Rose. The only one of about a dozen species treated this way in a pile which re-rooted was Chinese Bush-clover, Lespedeza cuneata. Volunteers hand pulled it successfully where it occupied about 10% of a 10’ x 10’ area with an equal amount of native narrow leaved mountain mint in bloom that they rescued. I back pack sprayed the other 2 patches in the park where nothing native was left.

At the 200 acre Swann Park 17 of the 19 non-native species are eradicated or nearly so. Only Japanese Stiltgrass and garlic mustard remain serious.  At Kokee State Park in Hawaii about 500 acres are also in the maintenance stage.

Return to Table of Contents