Tree of Heaven, Ailanthus altissima Deciduous Tree Size: up to 80 feet Flowers: clusters of yellow-green flowers at the ends of upper branches Leaves: pinnately compound with 11-14 leaflets Fruit: seeds develop in the fall, each seed is con tained in a sumara, yellow green changing to orange red in fall, brown in winter Bark: gray with a snake skin like texture, lenticles Rapid growth rate, saplings can grow 3-4 feet per year Mature tree can produce 350,00 seeds per year Seeds are transported by wind and water. Roots give off a toxin that can inhibit the growth of other plants. Root sprouts up to 50 feet from trunk. It out competes native species for light. It forms impenetrable thickets and tolerates adverse soil conditions. It is intolerant of full shade. Hand pulling of seedlings. Cutting twice per year, once in June, and again September 15th. Herbicide application, cut trees and apply undiluted triclopyr (Brush-B-Gone) to the stump or cut and spray resprouts. Deciduous woody twining vine Size: Can reach 18 meters in height Flowers: female plants produce small greenish flowers Leaves: variable in size and shape, alternate arrangement, broadly oblong to sub orbicular, tip acute to rounded, base cuneate to obtuse, margins finely toothed, glossy, yellow to gold fall color Fruit: 6 to 8mm long, change from green to bright yellow, after ripening the yellow outer covering splits open to reveal a red aril Root: Outer surface of roots has a characteristic bright orange color High reproductive rate - 95% of seeds germinate Seeds germinate and establish in low light conditions Seeds persist in soil for many years Plants grow in full sun to heavy shade conditions Plants spread by root suckers, particularly if cut Rapid growth rate Vine forms large colonies Asiatic Bittersweet overtakes and strangles desirable native plants. It forms a dense canopy that prevents the growth of other plant species beneath it. Higher growth rate with higher light levels : Cut stems and apply herbicide to cut ends. Triclopyramine (Brush-B-Gone) can be applied by paint brush to stem immediately after cutting. Foliar sprays used on large masses. Sprays are less likely to effect surrounding vegetation in October and ovember when most other plants are dormant. Vines can be cut and roots completely removed or sprouts repeatedly cut. Cutting without herbicide application can increase plant spread by encouraging new sprouts. Plants should be cut every two weeks. Continuous monitoring and removal of new plants. Asiatic Bittersweet Celastrus orbiculata
Multiflora Rose, Rosa multiflora Woody shrub with arching stems Size: 10-15 feet wide and tall Flowers: each flower is 1 inch wide and has five white petals with many yellow anthers, blooms in May to June. Leaves: alternate odd-pinnately compound, 5 to 11 leaflets, each 1-3 inches long. Margins are serrated. Fruit: rose hips ¼ to ½ diameter, green ripening to glossy red. Stems: arching stems with thorns Each plant can produce a million seeds per year. Birds distribute seeds. 90% of the seeds are viable, and can remain so for 20 years. Arching branches that reach the ground can root. Fast growth rate. It can grow 1 to 2 feet per week. Thorny branches and dense growth make it difficult to remove. It forms impenetrable thickets that exclude native species. It invades disturbed sites There is a multiflora rose seed chalid that infests 95% of seeds in Asia. This and several other biological control methods are being studied. Plants grow slowly for the first 1 or 2 years and expand rapidly after that. Repeated cutting can slow spread but will not eliminate it. Mowing 3 to 6 times per year around the perimeter of a stand will control expansion. Herbicide application of triclopyr (Brush-B-Gone) in spring before and during flowering. Application of glyphosate (Rodeo) after flowering until early fall. Cut stump applications work but are difficult to do because of the dense thorny branches. Follow up monitoring and removal will be necessary do to eliminate seeds remaining in soil. Tall perennial grass Size: up to 15 tall Flowers: bushy panicles in July and August, purple or golden in color Leaves: elongate leaves 1-1 ½ wide. Fruit: produces thousands of seeds annually, however viability is low Roots: dense network of roots and rhizomes, 80% of the plants biomass is below ground Spreads by rhizomes that can grow 10 feet in one year. Rapid growth rate, shades out other vegetation Fragments of rhizomes in transported soil or that wash down stream can grow into new plants ew plants can grow from seeds. Once established it overtakes native species, can change hydrology in marsh areas, and alters wildlife habitat. It becomes a quickly becomes a monoculture. It usually grows in tidal, non tidal brackish and fresh water marshes, on the shores of lakes and rivers and along roadsides. Water levels of 2 or more prevents seed germination. Cut at the end of July, leaving less than 6. After cutting, cover with black plastic anchored with sand bags or rocks. Remove plastic the following spring and pull or cut any shoots. Only works where sun will heat plastic. Combination of cutting plants in midsummer and applying glyphosate (Rodeo) when regrowth reaches 2-3 feet. Two to three weeks after herbicide application cut stalks to stimu late emergence of other plants. Common Reed, Phragmites australis
Japanese Knotweed, Polygonum cuspidatum Herbaceous perennial Size: large clumps to10 feet tall Flowers: small greenish white in branched sprays, bloom in August & September Leaves: 6 long by 4 wide, broadly oval to triangular with a pointed tip Fruit: small winged fruit containing very small black seeds Reproduces by seed Reproduces by rhizomes that can spread 15-24 feet. Early season emergence and fast growth rate shade out other plants Rhizome fragments in transported soil or that wash down stream can sprout and form new colonies. Can survive floods and is able to rapidly recolonize disturbed areas. It displaces all other vegetation. Once established it is almost impossible to remove. Any remaining rhizome can sprout into a new plant. These plants rarely invade undisturbed forest. They have high light requirements. : Minimum of three cuttings per year, to off set growth, possibly combined with herbicide application. Multi year cuttings required. When plants are gone, revegetate area with plants that will provide dense shade at ground level. Prevent establishment of new stands, monitor and eradicate new plants. Glyphosate (Rodeo) application when leaves are translocating to rhizomes, late summer, early fall. Repeated applications necessary. Cut stand in late June, allow to regrow, after August 1st spray with glyphosate (Rodeo). Deciduous large shrub or small tree Size: Common 6-18 ; Glossy 20 Flowers: dense clusters of 2-6 yellow-green 4 petaled flowers, near the bases of the leaf stalks. Male and female of separate plants, blooms in spring. Leaves: Common has broadly oval, rounded with a pointed tip and toothed margins, stay green into fall. Glossy Buckthorn has smooth leaf edges and the undersides of the leaves are hairy. Fruit: Small black seeds Twig: Common buckthorn has a spine at the twig tips, Glossy Buckthorn does not. Plants leaf out early Rapid growth rate. Can produce seeds on current season s growth. Seed production, dispersal and germination are effective. Fruit can float (6 days for Common, 19 days fro Glossy) making fall flooding a vehicle to distribute seeds. Forms large thickets. It forms large thickets that create dense and continuous shade. This prevents other plants from growing. Low light can limit establishment. Seeds are more successful in disturbed sites. Repeated cutting reduces vigor. Mowing prevents seedling establishment. Hand pulling newly established seedlings. Under planting with shade trees that grow to shade out buckthorn. Girdling and cutting in combination with glyphosate (Rodeo) application. Common Buckthorn, Rhamnus cathartica Glossy Buckthorn, Rhamnus fragula
Other Invasive Species Loosestrife, Lythrum salicaria Bittersweet nightshade, Solanum dulcamara Mulberry, Morus species
Management Plan Strategies: Summary Map Eradicate small stands of Phragmites, Japanese Knotweed, Loosestrife to prevent spread (urgent). Preserve existing trees by removing the Bittersweet vine that is strangling them (urgent). Minimize disruption of plant cover on banks: disturbed soils are condusive to the spread of invasive plants. Revegetate areas where invasives are removed. Where possible provide dense shade at ground level: it limits the growth of some invasive plants. Remove buckthorn, especially in areas where it is out competeing native shrubs. Remove bittersweet and buckthorn and revegetate with native plants (removal to include continual monitoring and additional removal). Identify areas where views should be retained and prioritize removals and revegetation in these areas. LEGED Tree of Heaven, Ailanthus altissima Asiatic Bittersweet Celastrus orbiculata Loosestrife, Lythrum salicaria Mulberry, Morus species Bittersweet nightshade, Solanum dulcamara Common Reed, Phragmites australis Japanese Knotweed, Polygonum cuspidatum Common Buckthorn, Rhamnus cathartica Glossy Buckthorn, Rhamnus fragula Multiflora Rose, Rosa multiflora