Treesearch

For the purpose of this paper, an exotic species is defined as "a plant or animal not native to North America." The history of folly surrounding the premeditated and accidental introduction of exotic animals has been well-documented. In 1963, Dr. E. Raymond Hall wrote, "Introducing exotic species of vertebrates is unscientific, economically wasteful, politically shortsighted, and biologically wrong." Naturalizing exotic species are living time bombs, but no one knows for sure how much time we have.

As highways cross the nation they provide safe travel for the vacationers, commuters, truckers, the military, farmers, congressmen, our families, and friends. Highway corridors provide safe passage for many plant invaders as well. Highway vegetation managers manage millions of acres of rights-of-way that cross your land. It is imperative that we understand each other's management strategies and cooperate as much as possible. If we do not, plant invaders that have no respect of political boundaries will prevail. This paper examines why roadside vegetation managers operate the way they do....

Selective and specific management for the control of exotic (non-native) plants is necessary for preservation of native plant communities. Managers of federal, state, or county land holdings and parks, wildlife areas, recreation areas, and historic sites are frequently charged with selectively managing the enhancement of desirable or native plant communities. In addition to exotic plant control programs, selective management may include vegetation control on fence rows, road rights-of-way, boundary line corridors, trails, and understory brush control for aesthetics.

Exotics have had a big impact on our environment. If you do not think so, just look at how many people believe that humans would not exist on this planet were it not for exotics. This belief centers on two main theories: (1) that humans could not have evolved were it not for a huge meteor from outer space striking the earth resulting in extinction of the dinasours, the rise of mammals, and the eventual appearance of humans; and (2) that the development of humans or human ancestors was the result of intervention by aliens from outer space; certainly, this would have been the ultimate exotic...

Garlic mustard (Alliaria petiolata) is a biennial herb that invades forested colllinunities and edge habitats, where it spreads rapidly and apparently displaces native herbaceous species, often within ten years of establishment. The plant has no natural enemies in North America, and is difficult to eradicate once established. Thus, the best and most effective control method for Alliaria is to prevent its initial establishment. In shaded and partially shaded communities lacking Alliaria the preferred method is to monitor annually, and remove all Alliaria plants prior to seed production....

It is difficult to document the total economic impacts of exotic insect pests on eastern U.S. forests. Annual losses to a single introduced pest, the gypsy moth, Lymantria dispar L., have exceeded $30 million from 1980 to 1996. The complicated behavior and actions of humans in accelerating the spread of this "global gypsy" are discussed. Examples of predicted economic impacts derived from pest risk assessments are given that demonstrate potential losses to other exotic insect pests.

At least 4,500 species of foreign origin have established free-living populations in the United States, of which about 15% cause severe economic or environmental harm. Between 1906 and 1991, just 79 species caused an estimated $97 billion in losses. Virtually every economic sector and area of the country is affected, with some of the biggest problems in the east. Usually, exotic species reach the United States with human help, often via international trade. Rates of entry fluctuate, but never drop to zero-creating an even-greater economic and environmental burden. Neither domestic policies...

Over the past several thousand years, Man has moved many plant species far beyond their historical native range. Many introduced plants that have become established outside of cultivation are benign (so far). However, some introduced species with free-living populations pose a threat to the biodiversity of natural areas and/or diminish the production capacity of managed or agricultural ecosystems. In the United States, 16 federal agencies have formed the Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW). This committee has developed a National Strategy...

In order to increase effective efforts to reduce the impacts of invasive alien plant species· on our natural areas, we must overcome numerous barriers. Some of these are technical in nature, e.g., determining the most appropriate control method for a specific species in a particular ecosystem, or devising a better program to exclude new invasive plant species from our country. To build the infrastructure that will allow us to tackle such scientific problems, however, we have first to enliven the political will to address the very concept of invasive alien plant species damaging our eastern...

In forests of North America the beech bark disease (BBD) complex affects American beech, Fagus grandifolia Ehrh. BBD begins when bark tissues, attacked by the exotic beech scale insect, Cryptococcus fagisuga Lind. are rendered susceptible to killing attacks by fungi of the genus Nectria. The principal fungus, N. coccinea var. faginata Lohm. and Watson, was probably introduced also, but the native pathogen, N. galligena Bres., also attacks and kills bark predisposed by C. fagisuga.