PROTECTING ENDANGERED SPECIES

Laws and conservation programs are helping to reduce endangerment worldwide. In the United States, the Endangered Species Act of 1973 protects endangered and threatened wildlife and plants from hunting, collecting, and other activities that harm them or their habitats. Since this law was enacted, the numbers of certain endangered animals, such as the alligator, bald eagle, and peregrine falcon, have increased so much that they have been removed from the endangered list or reclassified from endangered to threatened status.

Many wild species are protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This treaty, drawn up in 1973, aims to control trade in wild animals and plants, their parts, and products derived from them. Over 150 countries have joined the treaty. CITES bans trade in rhinoceros horn, cheetah fur, sea turtle shells and meat, and certain whale products. Elephant ivory was banned in 1989, but a 1997 decision enabled the African nations of Botswana, Namibia, and Zimbabwe to export a limited amount of stockpiled ivory to Japan. The ivory from these three nations was auctioned to Japanese buyers in 1999.

Various organizations publish lists of endangered species to improve public awareness. The IUCN (International Union for the Conservation of Nature and Natural Resources) compiles lists that include thousands of animal and plant species that are threatened or endangered.

Protecting habitat is the key method of preserving endangered species. Many governments and organizations have set aside nature preserves. Some zoos and animal research centers conduct programs that breed endangered species in hopes of returning their offspring to the wild. The programs have greatly improved the outlook for such endangered species as the black-footed ferret and the California condor.

ENDANGERED SPECIES

Endangered species are living things threatened with extinction-that is, the dying off of all of their kind. Thousands of species of animals and plants are endangered, and the number increases each year. Some examples of endangered species are blue whales, giant pandas, orangutans, rhinoceroses, sea turtles, snow leopards, tigers, and whooping cranes. Among endangered plants are running buffalo clover, Santa Cruz cypress, snakeroot, and many species of cactuses.

Each species of plant and animal plays a part in the delicate balance of its ecosystem, its relation to other living things and the environment. Thus, the extinction of large numbers of species threatens the survival of other living things, including human beings. As more species have become endangered, ecosystems have become unstable or collapsed. Fortunately, people have increased their efforts to protect endangered species.

Most biologists consider a species endangered if they expect it would die off completely in less than 20 years if no special efforts were made to protect it, or if the rate of decline far exceeds the rate of increase. Until the last few centuries, species became rare or died out as a result of natural causes. These causes included changes in climate, catastrophic movements in the earth's crust, and volcanic eruptions.
Today, species become endangered primarily because of human activities. Species mainly become endangered because of

1. loss of habitat,
2. wildlife trade,
3. overhunting, and
4. competition with domestic and nonnative animals.

Loss of habitat
Loss of habitat poses the greatest threat to the survival of wild species. Most animals and plants are specially adapted to live and reproduce in a specific environment or habitat and cannot survive when it is destroyed. The destruction of virgin forests by loggers and settlers and the conversion of natural grasslands into pasture for livestock have eliminated vast expanses of wildlife habitats. Marshlands have been drained for farmland and building projects. Coral reefs and many marine environments have become polluted, overfished, and even dynamited to obtain tropical fish and corals. Tropical rain forests contain the greatest variety of animal and plant life on earth, and they are being destroyed more rapidly than any other type of wild habitat.

Wildlife trade
Wildlife trade involves the capture of animals for pets, zoo specimens, and research subjects, and the killing of animals for their fur or other body parts. The capture of wild animals for commercial use has endangered many species. For example, the Spix's macaw, a parrot of Brazil, is nearly extinct in the wild because so many have been captured for private bird collectors. Many primates, including the orangutan, have become endangered by the illegal killing of the mothers to capture their babies for zoos and pet dealers. Gorillas, chimpanzees, and other primates are killed for their meat, which is sold in African markets.
Other animals have been killed in such large numbers for their fur, hides, tusks, or horns that they are nearly extinct. Rhinoceroses, wild chinchillas, the Tibetan antelope, and snow leopards are among these. Although such animals are now protected by law in the countries where they live, they are still poached (hunted illegally). Poaching also has seriously reduced the number of African elephants.

Overhunting
Overhunting has brought numerous species to the brink of extinction. The Caribbean manatee, the Asiatic lion, the dugong, and many species of pheasants have become endangered because people have hunted them for food and trophies. Many species are killed by people who believe that the animals threaten their livelihoods. Livestock owners, for example, may shoot, trap, or poison wild animals that they consider a danger to their herds. Farmers and ranchers in North America have nearly eliminated the red wolf and many species of prairie dogs, while herders in Africa have almost wiped out the Simian Wolf. Some people in the fishing industry blame seals, which eat fish, for reductions in their catch. Fishing crews have killed so many Mediterranean monk seals that fewer than 200 survive.

Competition
Competition with domestic and nonnative animals is a major threat to numerous plants and animals. On many islands, native birds, mammals, and reptiles have become endangered after people introduced domestic animals. Livestock overgraze vegetation, eliminating habitat. Domestic cats prey on birds and small mammals. Rats escape from ships and infest islands, killing small birds and their eggs. In mainland areas, stocking of game fish threatens native fish, and nonnative plants and animals crowd out many native species.

THE EFFECTS OF SLASHING DAN BURNING OF LAND MANAGEMENT

Slashing and burning is the preferred method of land clearing in the tropics for smallholders and large companies alike because it is cheaper, at least from a private perspective, and easier than available alternatives. In addition, fire eliminates field debris, reduces problems with weeds and other pests and diseases, makes nutrients available in the form of ash and loosens the soil to make planting easier. In some ways it is preferable environmentally compared to some other land-clearing methods.


For example, bulldozers and other heavy machinery cause soil compaction and erosion. Fire has many distinct advantages for low-income households: all other methods are more expensive; fire kills crop pests and diseases; and the ash provides much-needed fertilizer. Results of field experiments and surveys in Sumatra Indonesia demonstrate the key role that phosphorus (P) plays in resource management. Burning at low or medium intensity releases P into soil solution, but high-intensity fires reduce P levels. With greater fuel supply, hence hotter fires, the negative effects of heat on soil mineralogy offset the positive effects of additional ash.

DEFINITION AND UNDERSTANDING OF ECOSYSTEM MANAGEMENT

Definition and Understanding of  Ecosystem Management is a confusing mixture of good forest ecology principles and integrated or multiple use forest management. Advocates of ecosystem management analyze and describe ecosystem functioning in ways that recognize the need to maintain natural composition and structures of forest ecosystems from the landscape level to the stand or patch level.

However, while providing good information about forest functioning, practitioners of ecosystem management also continue to advocate methods and levels of timber extraction that degrade forest ecosystem composition, structures, and functioning necessary to maintain fully functioning forests through time. Conventional clearcutting and tree plantations are regular components of ecosystem management.

In contrast, ecologically responsible timber management is ecosystem-based, which means that the character (i.e. composition, structure, and functioning) and condition of ecosystems determine what types of human use can be carried out and in what ways and at what level of intensity these uses can occur while ensuring the maintenance of fully functioning forests at all scales through time.

Conventional timber management approaches described above all utilize concepts oriented to exploiting natural forests for timber and to producing crops of trees in short time cycles. Most of these concepts have little or no application in ecologically responsible timber management, because conventional approaches are focused on timber, while ecosystembased, ecologically responsible approaches are focused on forests.

UNDERSTANDING MULTIPLE USE FOREST MANAGEMENT

Understanding Multiple Use Forest Management is a system of forestry or timber management that assumes that a full spectrum of forest uses, from timber cutting and tourism to water production and nontimber forest products, can occur simultaneously throughout a forest landscape. When practiced across relatively large areas (500,000 hectares/1.2 million acres and larger), multiple use appears to work for a period of time.

However, under this regime, all forest stands with merchantable and economically accessible timber are planned for eventual timber cutting. Thus, as logging progresses through the landscape, both forest functioning and non-timber forest uses are progressively degraded.

Proponents of multiple use often attempt to convince other forest users that tree plantations are forests, and that society cannot afford to protect animals, plants, and microorganisms that stand in the way of economic growth. An ecosystem-based perspective maintains that human societies cannot afford not to protect forest functioning and maintain diverse forest uses that are the foundation for stable local economies.

DEFINITION OF SUSTAINED YIELD FORESTRY

Definiton of Sustained yield forestry is a concept that designs timber cutting and regrowing of timber crops to provide a perpetual yield of timber from a particular forest landscape. Initially, this concept embodied the commitment to non-declining timber yields over time.

However, the determination of annual cuts under sustained yield forestry has commonly been overly optimistic when considering both tree growth rates and the portion of a forest landscape that is suitable for the cutting and growing of timber crops over time. Thus, as a result, “sustained timber yields” have tended to decline through time as a result of excessive cutting rates that cannot be matched by the rate of regrowth of timber and by extraction of timber from land that subsequently proves to be unsuitable for timber growth and/or necessary to protect for non-timber forest uses.

Sustained yield forestry confuses timber or trees with forest ecosystems and fails to recognize that fully functioning forests are necessary to have trees, which are necessary to have timber. In contrast, an ecosystembased approach protects forest functioning at all scales through time as the first priority; and then seeks to sustain, within ecological limits, a diversity of human and non-human uses across the forest landscape.

DEFINITION OF FOREST STANDS | FOREST PATCHES

Definition of Forest Stands or Forest Patches refer to the ecosystem scale at which a relatively homogenous forest unit can be identified. The composition, structure, and ecological functions within a stand are similar enough that an ecologically responsible forest use prescription can be applied uniformly within the stand, without encountering changes in ecological parameters that may produce unexpected or undesirable results.

In conventional forestry, “stands” have largely been defined by narrow timber characteristics, which were in turn driven by short-term economic variables. However, in order to plan and carry out ecologically responsible forest uses within an ecosystem-based approach, stands must be defined in relation to whole ecosystem factors that are required to maintain fully functioning forests at the landscape and stand levels.

In other words, the boundaries of a stand are not determined by rigid human management criteria such as timber size and timber quality, but by the full spectrum of ecosystem parameters that have been shaped by natural disturbance patterns and that reflect the movement of energy, nutrients, water, and animals into and out of a particular ecosystem.

Human scales are closest to forest scales at the stand or patch level. For example, the stand or patch level is the scale where visible human modification occurs. However, an ecosystem-based approach must always consider that what occurs at the stand or visible scale will also have impacts on a variety of other scales, from the large landscape to the microscopic.