Most Common Invasive Species at Pictured Rocks National Lakeshore

Most Common Invasive Species of Pictured Rocks National Lakeshore 2019 Baby’s Breath (Gypsophila paniculata) Baby’s Breath (Gypsophila paniculata) Carnation Family Life History: A woody, perennial shrub with many stems that can grow 20-39 inches tall, although the flowers often flop over in the sand. The tiny white or pink flowers bloom throughout the summer and into early fall. The plant has a large, deep taproot that allows it to grow well in dry and poor soil conditions. Seeds are black, with two to five contained in capsules, and resemble pepper. The seeds can germinate in 10 to 15 days and plants grow rapidly. Distribution: There are four species of Gypsophila species in the Great Lakes region and all are considered invasive. Native to Russia in the lower Volga region, these plants can be found near shorelines and inland along roadsides and ditches. These species were thought to have been introduced either by escaping cultivation or by being accidentally included with other plants or soils. Uses: Ornamental. Used in floral arrangements. Impact on the Environment: Like other quick-growing invasive plants, baby’s breath outcompetes native plants and takes over their habitat, while providing no food or habitat for native wildlife. It is of special concern in fragile dune habitats where it can threaten rare species. Once established, baby’s breath can spread quickly. Each plant can produce 10,000 or more seeds, which are spread when the branches dry, break off and are moved in the wind similar to Russian thistle. At PIRO: Baby’s breath is a problem on Coast Guard Point in Grand Marais and has been treated there for several years. The park has treated private properties along the point and also at Woodland Park in an effort to keep it from spreading into park property. New plants are found each year but it is hoped that continued efforts will eventually control this plant on Coast Guard Point and keep it from spreading further. How to Control: Chemical control is recommended. Hand-pulling is not practical because of the large taproot. Baby’s breath plants are very difficult to get rid of, as small parts of the huge taproot can form new shoots even after most of the root has been destroyed. Beech Bark Scale (Cryptococcus fagisuga) nymph .03 mm Uninfected Beech Bark Beech Leaf Beech Bark Scale (Cryptococcus fagisuga) Life History: Adult beech scales are small (1/16 inch) insects related to aphids, oval and yellow, but appear white because they are covered with a protective white, waxy “wool.” Adult scales are wingless and parthenogenetic (no males are known – females clone each other). Females lay four to eight oval, yellow eggs underneath their protective wool. The egg stage lasts at least 20 days; then the first instar, or crawler (1/32 inch), which is the only mobile stage of beech scale, emerges. The active crawlers search for suitable feeding sites and settle in cracks and crevices in the bark. Often crawlers are dispersed passively via wind currents, or possibly on animals, and infest other trees. Upon settling, crawlers feed and produce protective wool, underneath which they overwinter (late-season eggs also may overwinter). Short-lived second instars emerge in the spring and soon molt to adults. The beech scale insect feeds on the tree by inserting its mouthpart through the bark of the beech tree and into the underlying live tissues where it can suck up sugars and other nutrients. These feeding sites create tiny wounds and the Nectria fungus can enter the tree through these wounds. Known predators in North America on the scale include the twice-stabbed ladybird beetle and several species of mites, but none have had much impact on reducing populations. Distribution: Native to Europe where it feeds on European Beech. Accidentally introduced to U.S. in 1890 on an ornamental beech in Nova Scotia. By 1932, it was found in Maine; by the 1960s it had spread to most of New England and New York. By 1975, it was in Pennsylvania, then New Jersey, Tennessee and as far south as North Carolina. Movement has been slow because insects do not fly, but are carried by wind, animals, birds, and by humans on infested firewood. Found in Ohio and West Virginia in the 1980s. In Michigan in 1990, and the UP by 2000. Found at Pictured Rocks in 2001. The native range of beech includes most of the East Coast down through the Carolinas and west to east Texas, and extends into Wisconsin, southern Illinois and eastern Missouri. Impacts on Environment: Has killed 50% of the beech trees in New England and severely damaged many more. However, it appears that beech is not as important and abundant component of New England forests, so the impact has not been as great. In some environments, such as here in Michigan, beech is the only mast producing tree, so loss of beech will have profound impacts on wildlife. Beech provide food and habitat for over 40 species of mammals and birds. Future studies will be needed to determine what this impact has. BBD has the potential to alter the species composition of the forests it occupies. Young trees are generally (but not always) resistant to the disease; they usually become infected after reaching 5 – 8 inches in diameter. At PIRO: Killing wave has been moving from east to west. Most beech trees in the eastern and middle parts of the park are dead. Mortality here is expected to reach 90%. Trees are dying even before the Nectria fungus is present. An infected tree may contain a million or more scale insects. Trees here at PIRO have been infected since 2001 – takes about 5 - 7 years for trees to die and then fall. More trees fall down here than other parts of the UP, perhaps because of our wind. The reason our mortality is greater than that of New England beech is not known – perhaps due to density, soil, climate, etc. Park staff are currently identifying and monitoring possible resistant trees. Control: Pesticides are not useful on BBD, as the insects exude a protective high- wax covering that resists the chemicals. For high value landscape trees, it is recommended that scale insects be physically scrubbed and high pressure washed. Management practices of removing infected beeches in a stand have been effective in preventing spread of the disease. Identifying and propagating resistant trees remains the best chance to preserve the species as a functional component of the forest. About Beech Trees: American beech grows best in rich, moist soils and is found in bottomlands and upland forests. Co-dominant tree of northern hardwood forests with sugar maple. Grow well under sugar maple; and sugar maple grows well under beech. Loss of beech will affect forest structure in unknown ways. Beech trees generally don’t produce nuts until at least 40 years old. At least 40 mammals and birds feed on the oil-rich nuts. Long-lived – can live 300 years or more. Highly shade tolerant. A much-revered tree in the British Isles; important in Celtic mythology. Common Burdock (Arctium minus) Common Burdock (Arctium minus) Composite Family Life History: A biennial thistle with purple flowers and distinctive prickly seed heads (burs). First year rosette leaves can be quite large, up to 2 ½ feet across. During the second year, burdock flowers July through October. Flowers are clumped on a central stalk, which can be up to 6 feet. Stem leaves are large, heart-shaped and very hairy underneath. At first glance, burdock appears very similar to Cocklebur, but burdock seeds are rounder and softer. Each bur contains about 40 seeds. Once the seed has ripened, the whole plant turns brown and dies. Also known as Lesser Burdock. Distribution: Common burdock is native to Europe and was introduced to the U.S. in the 1700s, possibly for medicinal purposes. Found now in nearly all 50 states. It is present in grasslands and forests, and along roadsides, ditches, stream banks, pastures, and disturbed habitats. It prefers sunlight and moist, well-drained soils, though it can tolerate most soil conditions. Uses: The inspiration for Velcro. The taproot and immature flower stalks are edible. It is also used in traditional and herbal medicine for various ailments. Impact on the Environment: Common burdock can become a problematic invader of pastures, hay fields and open prairie ecosystems. It acts as a secondary host for pathogens, such as powdery mildew and root rot, which affect economically important plants. It moves quickly into disturbed areas and crowds out native species. Burs can cling to the hair of wildlife, interfere with feathers and cause mouth irritation if eaten by animals. The above-ground portions of the plant may cause dermatitis in certain humans. At PIRO: Found in small populations in several areas of the park. Has a limited impact on the environment for now, but could become more serious if populations increase. Mainly a nuisance species. Currently treated where found through manual and chemical means. How to Control: First year plants are easy to pull up. Second year plants are controlled by cutting and bagging the flowering heads before seeds are produced. Common burdock can also be controlled by constant mowing before plants go to seed. Most broadleaf herbicides are also useful for control. Common Tansy (Tanacetum vulgare) Common Tansy (Tanacetum vulgare) Composite Family Life History: A perennial erect plant, 3 feet tall, up to 5 feet in shaded areas. A single stem branches toward the top into short stems forming a flat-topped cluster of numerous button-like flower heads. The non-hairy leaves are fern-like and have a strong herbal smell when disturbed.

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