It is the goal of the Invasive species management program to minimize impacts to authorized project purposes caused by nuisance levels of invasive vegetation. However, all programs must compete for limited funding. Therefore, the Army Corps of Engineers will not be able to treat all areas where invasive species reaches nuisance levels. Furthermore, as stewards of taxpayer money, it is understood that the benefits derived from treatment should exceed the cost of treatment. It is imperative that strong partnerships with state agencies, county governments, and private concessionaires be formed in order to meet public use demands.
Aquatic plants are an important component of an aquatic ecosystem, providing habitat for fish and waterfowl. However, when fast-growing plant species become well established, they can reach nuisance levels. This occurs when aquatic plants impact common uses of an impoundment such as hydropower production, recreation, or navigation. Management of aquatic vegetation is necessary to maintain the value of multiple uses in many large reservoirs where nuisance levels of aquatic plants have been reached. An example of a nuisance aquatic plant in our area is Hydrilla verticillata, commonly referred to as hydrilla.
Alligator Weed grows in a wider range of water and soil conditions that any other aquatic plant. This plant is native to South America and was probably brought to the US in the ballest of ships. The plant forms thick mats in water replacing native species and can result in fish kills and prevent recreational use as well as slow drainage that may cause flooding.
The Common Salvinia plant is a floating fern and is not native to the United States. This species is about 3/4 inch in width and occurs in still waters having high organic content. It has joined oval leaves covered with stiff hairs on its leaf surface. It has a root like structure which is actually modified fronds.
Cuban Bulrush might be noticed as a large colony of medium-height grasses growing in the water, with spherical inflorescences only somewhat visible among the many leaves.
Eurasian Water Milfoil has become a problem throughout the US with extensive stands reported in the Chesapeake Bay, TVA Lakes, and several areas in Florida. This submersed forming perennial remains green during winter and occurs throughout Alabama in both fresh and brackish waters. It forms dense mats that replace native plants and prevents light penetration causing fish habitat destruction. It spreads by plant fragments hitch-hiking on boats and trailers, but also produces seeds.
Hydrilla, a plant native to Africa, is presently the most threatening plant species in the aquatic environment. Its ability to out-compete all other aquatic plant species both natural and exotic for available habitat makes it a real danger to aquatic systems. Dense surface mats of hydrilla crowd out native plants and cause reduced oxygen conditions unsuitable for fish. The mats interfere with water flow, drainage, navigation, and often harbor mosquitoes.
Water hyacinth is a floating plant and is a invasive nuisance in much of the world where it often jams rivers and lakes with uncounted thousands of tons of floating plant matter. A healthy acre of water hyacinths can weigh up to 200 tons.
This plant grows in all types of freshwaters. It varies in size from a few inches to over three feet tall. They have showy lavender flowers with leaves that are rounded and leathery, attached to spongy and sometimes inflated stalks. It also has dark feathery roots.
Terrestrial plants are an important component of an terrestrial ecosystem, providing habitat for wildlife. However, when fast-growing plant species become well established, they can reach nuisance levels. This occurs when terrestrial plants impact common uses of a land resource such as wildlife management, forestry, agriculture, & recreation. Management of terrestrial vegetation is necessary to maintain the value of multiple uses in many public land resources where nuisance levels of terrestrial plants have been reached. An example of a nuisance terrestrial plant in our area is Cogon Grass & Chinese Tallow Tree (Popcorn Tree).
There are about 50 species of Ligustrum, all native to Europe, North Africa, and Asia. Ligustrum has been developed into an assortment of ornamental varieties in the U.S. and other parts of the world. Establishment of privet in many natural areas has occurred through its escape from cultivation. Chinese Privet is capable of invading natural areas such as floodplain forests and woodlands. The aggressive nature of privets allows for the formation of dense thickets that out compete desirable plants.
Chinese Tallow can invade a variety of habitats ranging from swampy to saline waters, and from full sun to shade situations. It is often found growing along roadsides, coastal areas, and streams. Larger specimens can produce up to 100,000 seeds that may be eaten and dispersed by birds, facilitating the spread of tallow. Regrowth often occurs from cut stumps or roots. Native species are crowded out once Chinese Tallow becomes established. The leaves and fruit are toxic to cattle and cause nausea and vomiting in humans.
Cogon Grass is an aggressive, rhizomatous, perennial grass that is distributed throughout the regions of the world. It has become established in the southeastern United States within the last fifty years, with Alabama, Mississippi, and Florida having extensive acreage of roadway and pasture infested with Cogon Grass. It does not survive in cultivated areas but becomes established along roadways, in forests, parks, and mining areas.
Japanese Climbing Fern can grow in sun or shade, damp, disturbed or undisturbed areas. It can grow so dense that it forms a living 'wall', leading to the elimination of seedlings and other native vegetation. It is also a major problem in pine plantations, causing contamination and harvesting problems for the pine straw industry. Old World climbing fern infests cypress swamps and other hydric sites, forming a monoculture. This massive infestation displaces all native flora and fauna, completely changing the ecosystem of the area.
This weedy yet attractive species is a native to North America and can be found in habitats such as disturbed sites, waste ground, roadsides, railroads and ditches. The plant can be identified by its glabrous, tall stems, large leaves, big yellow flowers from July to November and long drooping fruits. The leaves grow perpendicular to the stem giving the plant a distinctive appearance. Plants can grow to 3 meters tall or more.
Both elephant ear and Taro are herbaceous perennials with large leaves up to 6 feet in length. The common name was given because of its large, elephant ear-like leaves. Taro can be distinguished from elephant ears by the attachment of the leaf from the petiole. In Taro, the petiole attaches to the leaf several inches from the base of the ‘V’ of the leaf, while the petiole is attached directly at the base in elephant ears. The leaves are light green for elephant ear and darker green in color for Taro.