Lake Barcroft  
 
community

 

Invasive Management Plan for Community Owned Areas for 2010

 Fact Sheet and Workplan

 OBJECTIVES

  • Capitalize on support and momentum from concerned residents to do something about non-native, invasive  plants to help re-establish the health of the native woody plants in our vegetated buffer zones. 
  • Educate residents about the negative effects of non-native, invasive plant species on ecosystem function and health and the effects on stream water quality and the ordinances designed for the Resource Protection Areas. 
  • Preserve and develop healthy woodlots with uneven-aged stands of mixed trees, shrubs and ground cover with a floor of leaf litter and debris that are free of invasive plant species and provide high quality ecosystem functions, including those related to water quality. 
  • Promote an Early Detection Rapid Response program within Lake Barcroft 
  • to monitor and remove tiny invasive plant seedlings so as not to disturb the soil in our fragile RPA. Our goal is to monitor our common areas every few weeks so that we can remove invasive plants while they are tiny to avoid soil or native plant disturbance.
    – Invasive plant species removal is by hand, to minimize any soil disturbance
    – Herbicides and heavy equipment will not be used to avoid soil damage or possible leaching of chemicals into watershed

APPROACH

Trained horticulturists or landscape professionals, assisted by trained Fairfax County Master Gardeners and a few trained volunteers, will perform any invasive plant removal. Our goal is to minimize any disturbance of soil. Invasive, non-native plant species removal follows the guidelines for General Woodlot Management, Chapter 3.3 of the Riparian Buffers Guidance Manual, and is in accordance with known applicable laws and regulations. All removal will be by hand and no herbicides or heavy equipment will be used.  All volunteers will attend a training session that stresses the responsibility to protect the health of the ecosystems and the goals and regulations of the CBPA. 

We would like to monitor and remove tiny seedlings of any invasive plants through an Early Detection Rapid Response (EDRR) program that will allow the removal of small populations of non-native invasive plants. Small population is defined by area -- less than 50 square feet or population number -- less than 20 stems. A list of non-native invasive species that we would like permission to target and hand pull is attached.  All of these non-native species are listed in the Chesapeake Bay Local Assistance guidelines as "Highly or Moderately Invasive" and as listed under “Invasive Alien Plant Species of Virginia.” We would be happy to submit a regular report to the designated individual in the Department of Public Works and Environmental Services via email or other preferred means, documenting and listing invasive species removed, and native plants that were replanted in the few cases where soil was disturbed or left bare.

BACKGROUND

Invasive, non-native species harm water quality: Recognizing the importance of healthy riparian buffers in the stream water quality of our county and to downstream jurisdictions, some Invasive Management Area (IMA) sites will be located within the limits of Resource Protection Areas (RPA).  Our work is compliant with the goals of the Chesapeake Bay Preservation Ordinance. All species to be removed are listed as “Invasive Alien Plants” in the Riparian Buffer Guidance Manual Appendix B, published by the Chesapeake Bay Local Assistance and are recognized by leading experts as having severe negative ecological effects. These non-native, invasive species compromise the integrity of the riparian forest and any benefits to water quality riparian forests provide. These species are known to contribute to poor water quality. Invasive non-native plant species negatively affect water quality using a variety of mechanisms including:

  • interference with forest structure,
  • loss of biodiversity
  • and significant alteration with nutrient cycling. 

Specifically, vines such as English ivy, Japanese honeysuckle, mile-a-minute, multiflora rose, oriental bittersweet and porcelain-berry climb into the native forest canopy, interfering with tree and shrub structure and reducing forest health. Garlic mustard and Japanese barberry are associated with changes in soil pH, timing of nutrient availability, and absorption of nitrogen. Japanese stiltgrass, autumn and Russian olive, lesser celandine, Japanese stilt grass, and winged burning bush are commonly found in monocultures that inhibit native diversity and may lead to times of year when the soil is bare. A native, well-structured riparian forest is essential for filtering and slowing down water as well as shading the stream to regulate water temperatures. 

Management technique: Volunteers will remove plants by hand, requiring no heavy equipment and causing minimal to no soil disturbance (the specific methods allowed are listed below on a species specific basis). Ground disturbance will be kept to the minimum required to remove the roots of target plants and to carefully hand replant with native species if necessary. 

Replanting the sites with native species to create more robust and healthy riparian ecosystems is one of the priorities of our program. Monitoring will occur throughout the program, and if needed, soil stabilization will be provided by immediate planting of native vines and shrubs recommended for planting in RPAs of Fairfax County such as Virginia Sweetspire, Sweet Pepperbush, Southern Arrowwood Viburnum, Maple-leaved Viburnum, Low Bush blueberries, and Scarlet Honeysuckle or American Wisteria. Herbaceous, native, spreading groundcovers such as New York, Hay-scented, and Christmas ferns, Mayapples, Woodland Phlox will be used in shady areas to cover any bare soil, and native Switch grass, Little Bluestem, Broomsedge, Rough stemmed goldenrod, native asters, and coneflowers will be used to replant any bare soil in sunny sites.  Many of our buffer zone areas contain a diverse layer of native plants that will quickly spread and reestablish once small non-native invasive vines and herbaceous plants are removed. 

REMOVAL METHODS 

Bush Honeysuckle

  • Year round – Pull young seedlings after a rain and before they produce seeds. Remove flowering branches, but avoid cutting shrubs to ground, as this will encourage re-sprouting. 

English Ivy

  • Year round. Cut vines growing up trees or other vertical surfaces at ground level (do not leave stumps) and above head height, if possible, or at least two feet above the ground; vines on the ground may be rolled up like a carpet or hand pulled; to avoid dust and debris in eyes -- do not pull vines growing above head-height. All vegetation must be bagged and removed from the site due to the fact that it spreads readily by stem cuttings.

Garlic Mustard

  • Spring. Pull second-year plants and drop on site. Once flowers form, pull, bag and remove from site. Alternate method; cut flowering stalks from plants leaving root material in place. If plant is in seed, be very careful in removal, as it is very easy to spread the seed at this stage.

Japanese Barberry

  • Year round. Pull young seedlings after a rain and before they produce seeds. The entire root must be removed since broken fragments may re-sprout. If too big to pull, remove flowering branches, but avoid cutting shrubs to ground, as this will encourage re-sprouting. 

Japanese Honeysuckle

  • Year round. Cut vines growing up trees or other vertical surfaces above head height, if possible, pull up as much root system as possible, do not leave stumps.

Japanese Stilt Grass

  • June – August. Pull young sprouts and deposit in a single pile on site until seed set (September). This plant is an annual – early removal of sprouts will stimulate seed bank and more will germinate (this is a good thing), as you can remove 2 seasons of seeds in just one season.

Lesser Celandine

  • Spring. Only treat in February to mid-April. Handpull plants before they set seed or form bulbils. 

Mile-a-Minute

  • May-July. Pull young sprouts and deposit in a single pile on site until seed set in August-September; after seed set, debris must be bagged and removed from site. This plant is an annual – early removal of sprouts will stimulate seed bank and more will germinate (this is a good thing), as you can remove 2 seasons of seeds in just one season. Note: thorns are not as painful earlier in the season.

Multiflora Rose

  • Before September – The branches may be cut back to the crown - which may then be removed or left in place. If leaving in place, try to cut back the same plants three times in one growing season. Rose dies back to the root system in fall and winter – if removing rose this time of year, focus on the root system.

Oriental Bittersweet

  • Spring – October. Only cut vines that are climbing into the tree canopy. Cut vines both at ground level (do not leave stumps) and at least six feet above ground level. Evidence shows that vines will re-sprout from the roots, so repeatedly cut the same vines over the course of a single season. Fruit will appear in June, but will not be viable until October. Root material should be bagged and removed from the site.

Porcelain Berry

  • Spring –October. Cut vines both at ground level and at least six feet above ground level. Evidence shows that vines will re-sprout from roots, so repeatedly cut the same vines over the course of a single season. Fruit will appear in September and all cuttings should be carefully bagged and removed from site. Cut sections of vine can be cut into small pieces and left on site.

Winged Burning Bush

  • Year round. Pull young seedlings after a rain and before they produce seeds. The entire root must be removed since broken fragments may re-sprout. If too big to pull, remove flowering branches, but avoid cutting shrubs at ground level. 

Wintercreeper

  • Year round. Cut vines growing up trees or other vertical surfaces at ground level and above head height, if possible, or at least two feet above the ground; vines on the ground may be rolled up like a carpet or hand pulled; do not pull vines growing above head from trees. All vegetation must be bagged and removed from the site due to the fact that it spreads readily by stem cuttings. 

TRAINING & OVERSIGHT

All IMA Volunteer Leaders will attend training sessions so that they: 1) become familiar with the regulations regarding working in a RPA; 2) learn the proper method of invasive plant species control for the species on their site; 3) develop an understanding of the ecology of the Chesapeake Bay Watershed. I am a horticulturist, and along with trained Fairfax County Master Gardeners, and Landscape Professionals, will directly supervise all invasive removals.

TIMING

  • Work will typically include monthly monitoring and removal events, and a planting event if needed.
  • Invasive removal workdays will occur periodically year round, as weather permits, with monitoring for invasive seedlings approximately every 4 weeks as needed at each site.
  • Any required plantings will occur by November 2010.

LOCATIONS

Beach 5 Peninsula

Parcel Number(s): 0611 11; 675 676 677 678 679 680

Square Footage: 31,250 sq. ft. IMA area; 181,500 sq. ft total area

Description of Site: Dredge spoil peninsula created in early 70's with a combination of grass picnic area surrounded by wooded buffer plantings and woodlot with trail and small, sandy beach. 

Targeted Invasive Species: Buffer zone plantings and trees are being invaded with Porcelain berry, Mile-a-minute vine, English Ivy, Japanese Honeysuckle, Multiflora Rose which are smothering and weighing down native trees and understory shrubs. Localized areas along woodlot and paths are being invaded by garlic mustard, lesser celandine, burning bush and bush honeysuckles.

Restoration Plan: vines will be cut from trees as described under each species with special care not to harm indigenous vegetation. Natural regeneration of shrubs and groundcovers will be encouraged. Small seedlings will be pulled. Any vine or shrub that is pulled will be replanted with indigenous shrubs species already growing in this area such as: maple leaved and arrowwood viburnums, pinxterbloom azaleas, spicebush, early low bush blueberries, and American Wisteria, and any bare soil left after hand pulling herbaceous plants will be immediately replanted with indigenous spreading groundcovers such as Christmas and New York ferns, White Wood Aster, Mayapples, and false solomon's seal.

Beach 4

Parcel Number(s): 0611 11; 893 894 895

Square Footage: 3250 sq. ft. IMA area; 61,250 sq ft. total area

Description of Site: Mostly sandy beach bordered by woodlot and wooded grassypicnic area.  We do not have much of an invasive problem in this area.

Restoration Plan: We will monitor the area every few weeks to remove any small seedlings of invasive plants such as Japanese Honeysuckle, Porcelain berry vine, mile-a-minute vine and English Ivy if and when they occur along vegetated lake edge and around the boat racks. We anticipate cutting vines and preferably hand pulling seedlings before they become established, so there will be little to no soil disturbance in this area. Any plants removed will be replaced with arrowwood viburnums, Virginia sweetspire, Woodland phlox, Christmas ferns, New York ferns, or white wood asters. In sunny areas, Switch grass and rough stemmed goldenrod will be used.

Beach 3

Parcel Number(s): 0613 14; 449 450 451 452 453 454

Square Footage: 10,500 sq. ft. IMA area; 79,500 sq. ft total area

Description of Site: Combination of wooded area, sandy beach and picnic area, and dredge spoil basin created in the early 70's. Our focus will be on wooded area of this property only.

Targeted Invasive Species: Invasive plants occur mostly in the wooded areas and include: Japanese Honeysuckle, Porcelain-berry vine, English Ivy, and Garlic mustard.  The vines are climbing and smothering the woody plants and trees. 

Restoration Plan: Vines will be cut and disposed of, with special care not to harm any indigenous vegetation. If any soil is disturbed or left bare, indigenous small trees and shrubs and herbaceous plants already present in this area will be replanted immediately such as Eastern Redbuds, Serviceberries, Indigobush, New York ferns, Pennsylvania Sedge, Pussytoes, White Wood Asters, and Mayapples. Shrubs planted will include Virginia Sweetspire, Pinxterbloom azaleas, and low bush blueberries

Beach 2

Parcel Number(s): 0613 14; 366 367 368 369 370 371

Square Footage: 5900 sq. ft. IMA area; 90,000 sq. ft total area

Description of Site: Wooded hillside, small picnic area, and sandy beach

Targeted Invasive Species: The wooded slopes of Beach 2 contain some of the best and least disturbed examples of forested slopes in Lake Barcroft.  Occasional invasive vines as described above for Beach 3 encroach into this area and climb and smother trees and indigenous vegetation.  Additionally Japanese Barberry was planted as an ornamental in the picnic area, and ideally should be removed and replaced with indigenous shrubs such as Inkberry holly or Virginia Sweetspire.

Restoration Plan: We will carefully cut or remove vines of Japanese Honeysuckle, Porcelain-berry vine, English Ivy.  We will encourage regeneration of the rich herbaceous and shrub layers of this forested slope, but, will replant with the same abundant species found here, such as blood root, Mayapples, New York and Christmas ferns, White Wood Aster, false Solomon's seal.

Beach 1

Parcel Number(s): 0613 14; 86 87 88 89 90

Square Footage: 2,000 sq. ft. IMA area; 50,000 sq. ft. total area

Description of Site: Grassy area surrounding sandy beach with only a few trees and shrubs

Targeted Invasive Species: Since this area is mostly lawn and sandy beach there are not many invasive species.  

Restoration Plan: Monitor area for possible seedlings of invasive plant as listed in this report to remove while tiny. Any plants removed will be replaced with white wood asters, ferns, and switch grass. We strongly encourage planting of indigenous trees and understory plantings here to encourage the restoration of a vegetated buffer zone.

Community Garden

Parcel Number(s): 0604 13; A1

Square Footage: 19,500 sq. ft IMA area; 157,500 sq. ft. total area

Description of Site: Grassy area surrounded by ornamental garden and degraded woodlot, abutting Holmes Run Stream on one side.

Targeted Invasive Species: Trees and shrubs in the woodlot are being badly smothered by layers of Porcelain-berry vine, Japanese Honeysuckle, and English Ivy especially along woodlot path and along edge of property near neighbors with invasive plants that spread over boundary. 

Restoration Plan: Vines will be cut or pulled as described under each species with care not to disturb soil or damage indigenous vegetation.  Any disturbed soil will be replanted with appropriate indigenous vegetation such as Sweet Pepperbush, Serviceberries, Virginia Sweetspire, Pinxterbloom azaleas, New York, Cinnamon, and Ostrich ferns. 

Only this past year, Garlic mustard and lesser celandine have begun invading damp areas along the wooded path from upper Holmes Run, and we plan to hand pull these few seedlings before they can spread out of bounds and disturb much soil.  Any plants removed will be replanted with spreading groundcovers such as New York ferns, White Wood Aster, Mayapples.

Replacement Plant Sizes:

Trees: Replacement trees will be 6' or more in height and between 1.5 - 2" caliper or 15 gal container or larger.

Shrubs and Vines: Replacement native shrubs will be 3 - 5 gallon containers depending on availability and root space among trees.

Herbaceous groundcovers: will be planted in 1 - 2 gal containers sizes.