Chapter 10: Wild Species and Biodiversity10.1 The Value of Wild Species

I. Ecosystem capital is the sum of all the goods and services provided to human enterprises by natural systems. The basis of most of the natural capital is ecosystems, and the basis of ecosystems is the plants, animals, and microbes that make them work.A. To maintain the sustainability of these ecosystems, their integrity must be

preserved, this means maintaining their resilience and biodiversity. Biological Wealth

I. The Millennium Ecosystem Assessment states that about 2 million species of plants, animals, and microbes have been classified, but there are many more to be found. These natural species, collectively known as biota, are responsible for the structure and maintenance of all ecosystems. They and the ecosystems they form represent wealth—the biological wealth—that comprises most of the ecosystem capital that sustains human life and economic activity.A. This richness in species is a major dimension of Earth’s biodiversity.

Two Kinds of ValueI. In the 19th century, naturalists called for an end to the thoughtless slaughter of wild

animals, and the US public began to be sensitized to the losses. People began to see natural species as worthy of preservation, and the naturalists began to look for ways to justify their calls to conserve nature.A. There was an emerging sense that species should not be hunted to extinction.

II. The first kind of value is instrumental value. A species or individual organism has instrumental value if its existence or use benefits some other entity.A. This kind of value is usually anthropocentric, that is, the beneficiaries are human

beings.III. The second kind of value that must be considered is intrinsic value. Something has

intrinsic value when it has value for its own sake, that it, it does not have to be useful to us to possess value.

IV. The value of natural species can be categorized as follows: 1. Value as sources for agriculture, forestry, aquaculture, and animal husbandry2. Value as sources for medicines and pharmaceuticals3. Recreational, aesthetic, and scientific value4. Value for their own sake

Sources for Agriculture, Forestry, Aquaculture, and Animal HusbandryI. Wild populations have numerous traits for competiveness, resistance to parasites,

tolerance to adverse conditions, and other aspects of vigor. In contrast, populations grown for many generations under the conditions of agriculture tend to lose these traits because they are selected for production, not resilience.A. In the process of breeding plants for maximum production, virtually all genetic

variation is eliminated.

B. When provided with optimal water and fertilizer, cultivators produce outstanding yields under the specific climatic conditions to which they are adapted. With their minimum genetic variation, however, they have virtually no capacity to adapt to any other conditions.

C. To maintain vigor in cultivators and to adapt them to different climatic conditions, plant breeders comb wild populations of related species for the desired traits. When found, these traits are introduced into the cultivator through crossbreeding or biotechnology. This trait came from wild biota.

D. If natural biota with wild populations is lost, the options for continued improvements in food plants will be greatly reduced. The potential for developing new agricultural cultivars will also be lost.

II. Another area in which wild species have instrumental value is pest control. Natural enemies and genes for increasing resistance can come only from natural biota. Destroying natural biota may destroy such opportunities. A. Natural biota can be thought of as a bank in which the gene pools of all the

species involved are deposited. As long as natural biota is preserved, there is a rich endowment of genes in the bank that can be drawn upon as needed. Thus, natural biota is referred to as a genetic bank.

Sources for MedicineI. Earth’s genetic bank also serves medicine. The search for drugs in the tropics has led

to the creation of parks and reserves to promote the preservation of natural ecosystems that are home to traditional plants.A. According to the WHO, 80% of the world’s people depend on non-Western

medicine that in turn depends on natural products. 25% of all pharmaceuticals in the United States contain ingredients originally derived from native plants.

Recreational, Aesthetic, and Scientific ValueI. The species in natural ecosystems also provide the foundation for numerous

recreational and aesthetic interests. It is very likely that much of the broad public support for preserving wild species and habitats stems from the aesthetic and recreational enjoyment people derive from them.

II. Recreational and aesthetic values constitute a very important source of support for maintaining wild species.A. Recreational and aesthetic activities support commercial interests. Ecotourism—

whereby tourists visit a place in order to observe wild species or unique ecological sites—represents the largest foreign-exchange-generating enterprise in many developing countries.

Value for Their Own SakeI. Some observers believe that the most important strategy for preserving all wild

species is to emphasize the intrinsic value of species, rather than the unknown ecological and economic instrumental values.

10.2 Saving Wild SpeciesI. In the US, property owners do not own the wildlife living on their lands; wildlife

resources are public resources, protected under the Public Trust Doctrine. The government holds these resources in trust for all people, and is obliged to provide protection for those resources.

Game Animals in the United StatesI. As game animals became scarce in the face of unrestrained hunting, regulations were

enacted. State governments enacted laws establishing hunting seasons and bag limits and hired wardens to enforce the laws.A. Using hunting and trapping fees as a source of revenue, state wildlife managers

enhance the habitats supporting important game species and provide special areas for hunting. They monitor game populations and adjust seasons and bag limits accordingly.

B. Another source of revenue for wildlife conservation comes from federal excise taxes placed on hunting, fishing, shooting, and boating equipment. Game preserves, parks, and other areas where hunting and fishing are prohibited are maintained to protect habitats, as well as breeding populations that can disperse to other habitats.

II. Hunting has many positive aspects. Many hunters belong to organizations dedicated to the game they are interested in hunting.A. Defenders of hunting and trapping argue that their prey are often animals that lack

natural predators and would increase to the point of destroying their own habitat.III. Common game animals are well adapted to rural and suburban environments. Thus

adapted and protected from overhunting, viable populations of these animals are being maintained. Some serious problems have emerged:

1. The number of animals killed on roadways now far exceeds the number killed by hunters.

2. Many nuisance animals are thriving in highly urbanized areas, creating health hazards.

3. Some game animals have no predators except hunters and tend to reach population densities that push them into suburban habitats, where they cannot be hunted effectively.

4. In recent years, suburbanites have been increasingly attacked by cougars, bears, and alligators as urbanization encroaches on the wild.

5. Coyotes are now found in every state and in increasing numbers. They are difficult to control and often attack young children.

6. Suburban parks and lawns have become home to exploding flocks of Canada geese.A. Wildlife Services responds to requests from livestock owners, farmers,

homeowners, and others concerned with economic damage, human health,

and safety to remove nuisance animals and birds. They are a controversial agency because their method of removal is usually to kill.

Protecting Endangered SpeciesI. Florida and Texas were first to pass laws protecting plumed birds. In 1900 Congress

passed the Lacey Act, forbidding interstate commerce in illegally killed wildlife.A. Since then, numerous wildlife refugees have been established to protect the birds’

breeding and migratory habitats. B. The Lacey Act has become the most important piece of legislation protecting

wildlife from illegal killing or smuggling. Under the act, the US Fish and Wildlife Service can bring federal charges against anyone violating a number of wildlife laws.

II. Congress took another major step when it passed a series of acts to protect endangered species. The most comprehensive and recent of these acts is the Endangered Species Act of 1973.A. An endangered species is a species that has been reduced to the point where it is

in imminent danger of becoming extinct if protection is not provided.B. The act also provides for the protection of threatened species, which are judged to

be in jeopardy but not on the brink of extinction. When a species is officially recognized as being either endangered or threatened, the law specifies substantial fines for killing, trapping, uprooting, modifying significant habitat of, or engaging in commerce in the species or its parts.

C. There are three steps in the process of designating a species as endangered or threatened:

1. Listing. Species may be listed by the appropriate agency or by petition from individuals, groups, or state agencies. Listing must be based on the best available information and must take into account any economic impact the listing might have.

2. Critical habitat. When a species is listed, the agency must also designate as critical habitat the areas where the species is currently found or where it could likely spread as it recovers. This extends to privately held lands.

3. Recovery plans. The agency is required to develop recovery plans that are designed to allow listed species to survive and thrive.

D. Opposition to the act comes from development, timber, recreational, and mineral interests, which claim that the act is costly and favors the rights of animals over human economic activity.

III. The ESA requires that listing and critical habitat decisions be made solely on the basis of available scientific data. However, data is often not available and most rare species are rarely known or studied. Further, species are only listed after they have already reached dangerously low populations, which makes recovery difficult.

A. Some believe that the act does not go far enough. A major shortcoming is that protection is not provided until a species is officially listed by the FWS as endangered or threatened and a recovery plan is established.

B. Another contentious issue is the establishment of critical habitat. Opponents believe that the critical habitat designation places unwanted burdens on property owners, and assert that the critical habitat findings have little merit in conserving species. By restricting the desires of property owners to use their land because it contains an endangered species, the ESA, in the views of opponents, “takes” the property in the constitutional sense of the term. To trigger a 5th Amendment compensation, the courts have ruled that the economic impacts must be severe, and have favored the ESA over plaintiffs in all but one case.

IV. The Northwest Forest Plan employs the ecosystem management approach now adopted by the Forest Service. It set aside 7.4 million acres of federal land in California, Oregon, and Washington where logging is prohibited in stands of trees older than 80 years.

10.3 Biodiversity and its DeclineI. Over time, natural selection leads to speciation—the creation of new species—as well

as extinction—the disappearance of species. Over geological time, the net balance of these processes has favored the gradual accumulation of more and more species—in other words, an increase in biodiversity.

The Decline of Biodiversity I. Species populations are a more important element of biodiversity than just the

species’ existence. It is the populations that occupy different habitats and ranges and that contribute to biological wealth as they provide goods and services important in ecosystems.

II. Across North America, general population declines of well-studied wild species are also occurring. Worldwide, the loss of biodiversity is even more disturbing.

Reasons for the DeclineI. Extinctions of the distant past were largely caused by processes of climate change,

plate tectonics, and asteroid impacts. Current threats to biodiversity result primarily from the following three human activities: habitat change, introduced alien species, and exploitation. A. Disease, pollution, and climate change play lesser roles but could become more

important in the future, as all these factors are expected to intensify with time.B. The losses will be greatest in the developing world, where biodiversity is greatest

and human population growth is highest.C. One key to holding down the loss of biodiversity lies in bringing down human

population growth.II. By far the greatest source of loss is the physical alteration of habitats through the

processes of conversion, fragmentation, and simplification. Natural species are

adapted to specific habitats, so if the habitat changes or is eliminated, the species will go with it.A. Habitats like cropland that replace natural habitats are quite inhospitable to all but

a few species that tend to be well-adapted to the new managed landscapes.B. Natural landscapes tend to have patches of habitat that are well connected to

other, similar patches. Human-dominated landscapes, however, consist of a mosaic of different land uses, resulting in small, often geometrically configured, patches that frequently contrast highly with neighboring patches. Small fragments of habitat can only support small numbers and populations of species, which are vulnerable to extermination.

C. Reducing the size of a habitat creates a greater proportion of edges, a situation that favors some species, but may be detrimental to others.

D. Human use of habitats often simplifies them.III. An exotic species is a species introduced into an area from somewhere else. Because

the species is not native to the new area, it is frequently unsuccessful in establishing a viable population and quietly disappears. Occasionally, an alien species finds the new environment to its liking and becomes an invasive species, spreading out and perhaps eliminating native species by predation or competition.

IV. Removing whales, fish, or trees faster than they can reproduce will lead to their ultimate extinction. Nevertheless, overuse is another major assault against biodiversity. A. Overexploitation is driven by a combination of greed, ignorance, and desperation.

V. Poor management often leads to a loss of biodiversity. This not only depletes resources, but sets in motion a cycle of erosion and desertification, with effects beyond the exploited area.A. One form of overuse is the trafficking in wildlife and in products derived from

wild species. B. Pollution destroys or alters habitats, with consequences just as severe as those

caused by deliberate conversions.Consequences of Losing Biodiversity

I. Biodiversity is essential for the ecosystem services and goods that human societies derive from the natural world. Biodiversity loss threatens the attainment of almost all of the Millennium Development Goals.

II. It is the dominant plants and animals that determine major ecosystem processes such as energy flow and nutrient cycling. Thus, simplifying ecosystems by driving rarer species to extinction will not necessarily lead to ecosystem decline.A. It is possible to lose keystone species—species whose role is absolutely vital to

the survival of many other species in an ecosystem. It is also possible to introduce species that can become new dominants in ecosystems. They have an impact on both biodiversity and functionality as they crowd out existing species.

Protecting BiodiversityInternational Developments

I. Serious efforts are being made to preserve biodiversity around the world, especially in the tropics.A. One of the these efforts is the work of the World Conservation Union, which

maintains a Red List of threatened species.