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Species Diversity and Preservation II. Alien species - refers to a species that is transported or established outside of its native range. This transport may or may not be intentional. Introduced species - is an alien species that was transported intentionally.
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Alien species - refers to a species that is transported or established outside of its native range. This transport may or may not be intentional. Introduced species - is an alien species that was transported intentionally. Invasive species - is an alien species that disrupts the normal functioning and/or structure of an ecosystem. A naturalized species is one that has become established and is self-sustaining in a new area. Terminology
Invasive Species - USA The current environmental, economic, and health costs of invasive species could exceed $138 billion per year, more than all other natural disasters combined. West Nile virus and Purple loosestrife (northeast) Kudzu, water hyacinth, nutria, and fire ants (southeast) Zebra mussels and leafy spurge, (Midwest) Salt cedar, Russian olive, and Africanized bees (southwest) Yellow star thistle, Asian clams, and sudden oak death (California) Cheatgrass, knapweeds and thistles (Great Basin) Whirling disease of salmonids (northwest) Hundreds of species (microbes to mammals) (Hawaii) Brown tree snake (Guam)
Factors that Contribute to Community Vulnerability to Invasion Vacant niches Escape from biotic constraints Community species richness Disturbance before or upon immigration
Exotic Species Introductions (Biotic Pollution) Other than habitat loss (and possibly exploitative hunting/fishing practices), the introduction of exotic species has caused the greatest threat to biodiversity. Introduced competitors and predators have a greater negative effect on local organisms than do native competitors or predators because exotic species have not coevolved with those native species. Therefore, the native species have no adaptations to the introduced species. Islands (e.g., Hawaii, Australia) are particularly susceptible to introductions because predators are often rare on islands.
Introduced Species in Hawaii With the arrival of Captain James Cook in 1778, the environment of Hawaii began to change dramatically. These first European settlers brought a number of new species including; pigs, goats, sheep, and many ornamental and horticultural plants. It is now estimated that an average of 20-50 new species arrive annually in Hawaii. The subsequent loss of native species has decreased the diversity and produced economic problems.
Introduced Species in the Continental USA • Kudzu: Introduced in the southeastern U.S. in the 1930s as a control for erosion. Has overgrown everything in its path, causing millions of dollars in damage annually.
Introduced Species in the Continental USA • Purple loosestrife: Cultivated for its beautiful purple flowers, this wetland plant escaped into New England marshes a century ago. • It now fills the wetlands across much of the northern U.S. and southern Canada, reducing wetland biodiversity.
Introduced Species in the Continental USA • Japanese honeysuckle: This aggressive vine seriously alters or destroys the understory and herbaceous layers of communities it invades, including prairies, glades, floodplains, and upland forests.
Cane toads:Bufo marinus is the most introduced amphibian in the world. It outcompetes native amphibians and also causes predator declines because they have no natural immunity to the bufotoxin it secretes. Introduced Species in the Continental USA
Zebra Mussels Introduced from the ballast water of cargo ships from the Caspian Sea. They glue themselves to any solid surface. These mussels clog intake pipes, cover the bottom of lakes, and invaded the Hudson and Mississippi Rivers. They cost $400 million/year in removal costs, and exclude other, native mussels.
Zebra Mussels The estimated cost to industry, shipping and sport fishing was $5 billion in the Great Lake region alone by the year 2000. Each female can produce one million eggs a year. Being colonial, as many as 500 000 mussels may be attached as a solid mass on each square meter of substance, encrusting and clogging various utilities like the intake ducts and pipes of power stations and industries, drains, etc.
Lampreys The impact of lamprey on commercial fishing in the Great Lakes.
Protecting Species • Habitat Protection: • Placement of habitats into Preserves, Reserves, and National Monuments, can protect both endangered species, as well as provide ecosystem stability. • Risks: • Multiple use (recreation, timber extraction, grazing use, mineral extraction) can often conflict with preservation of a habitat. • “Paper” parks are often logged, farmed, mined, or poached. Poaching is a common practice, even in U.S. protected areas.
Protecting Species Sometimes the protection of a specific habitat (e.g., freshwater river) involves monitoring of other ecosystems (e.g., riparian environment).
Protecting Species • Debt for Nature Swaps: • The purchase of debt by organizations at a much lower rate (10 cents on the dollar), and then forgiveness of that debt in return for that countries efforts to make reserves in certain areas. • The largest of the “debt for nature swap” organization is the World Wildlife Fund (WWF). Since its inception in 1961, WWF has invested in over 13,100 projects in 157 countries. The annual budget is about $20 million, almost all from private donations.
Examples of Non-governmental Organizations (NGOs) Involved in Defending Species and Habitats Nature Conservancy Conservation International World Wildlife Fund Environmental Defense Fund Sierra Club Greenpeace.
Protecting Species by Laws • Hunting and Fishing Laws - Limit number of animals that can be ‘harvested’ on a yearly basis. • Usually animal populations are monitored so that hunting pressures do not limit the populations. • For some animals, such as deer, management practices favor them, so they may be even more abundant than prior to settlement of the U.S. • In these cases, the species can be more of a problem for habitat integrity than a species that needs protection.
Zoos, Botanical Gardens, Captive Breeding Programs Breeding of endangered animals (Cheetahs, other big cats, rhinos, other large game animals), conservation of plant species (sometimes through the storage of seeds in banks), may provide a haven from which to reestablish very endangered species. Costs are prohibitive.
Restoration Ecology • Restoration Ecology means to bring back a habitat to a former condition. When overexploited, ecosystems degenerate and services decline. Ultimately we need the capture of renewable resources while sustaining the global ecosystems that convert sunlight into ecosystem services. • Principles and Goals: • Need to consider several levels - genes, populations, ecosystems at the same time. Ongoing research to collect data on the restored site to monitor changes.
Curtis Prairie in Wisconsin: In 1934, seeds were collected from remnants along railroad right-of-ways and in pioneer cemeteries and cultivated in an old field. Periodic fires helped to establish the prairie; it now serves as a seed source for other prairies. Restoration Ecology
Restoration Ecology • Guanacaste National Park (Tropical dry forest): • In an attempt to restore a tropical dry forest in Costa Rica, used existing livestock to germinate seeds, fire control to help establish forests, and intensive labor to eliminate weedy plants.
Restoration Ecology Rivers - The Army Corp of Engineers straightened and drained naturally occurring meanders in rivers. Now, after realizing the value of wetlands along rivers as a flood control (and for groundwater recharge), they are trying to restore wetlands.
Endangered Species Act of 1973. • Regulate activities involving endangered species, including taking, selling, or transporting any endangered animal. Protecting these species often involves preserving habitats that are also endangered, as well as the other unidentified species using that habitat. • Recovery Plans: Several success stories, • 1. American Alligator, which was overhunted for meat and skin • 2. Eagles, hawks, and falcons which were decimated by DDT.
Definitions Resulting from Endangered Species Act Federal Endangered - animal or plant species, subspecies or varieties in danger of extinction throughout all or a significant portion of their range. These are considered "Federally-listed" or "listed" because a final rule was published in the Federal Register. Federal Threatened - species, subspecies or varieties likely to become endangered within the foreseeable future throughout all or a significant portion of their range.
Policy Responses Population: Governments can help to create the conditions where having fewer children will make sense, and where people have the means to reach their desired fertility. And if fertility can be reduced, there will usually be environmental benefits.
Policy Responses Consumption: Realistic approach is to divert consumption into channels with lower environmental costs, while ensuring that people still enjoy the end products or services they need for dignity and comfort. The balance of taxes and subsidies can be shifted so as to make environmental "bads" like excessive car or fossil-fuel use less attractive to consumers, and environmental "goods" such as energy-saving technology more attractive.
Policy Responses Technology: The heaviest burden will fall on the technology element of the equation. If, as is quite likely, the scale of the world economy triples by 2050, then technological changes will have to reduce the environmental impact of our activities by two thirds - just to prevent the present rate of damage from increasing.