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Part 2
Importance of biodiversity

Many biologists who study biodiversity confine themselves to the objective assessment of ecological processes. Others believe that scientists should comment on the moral, philosophical and political aspects of biodiversity.

The first approach risks losing many species of plants and animals to exploitation or development, whereas the second leads people to question the impartiality of scientific conclusions. Which do you think is preferable?

Arguments for protecting biodiversity fall into two categories:

Biodiversity has an intrinsic value that is worth protecting regardless of its value to humans. This argument focuses on the conservation of all species, even if they are ecologically equivalent species.

Biodiversity performs a number of ecological services for humankind that have economic, aesthetic or recreational value. This argument focuses on conserving ecologically nonequivalent species since ecologically equivalent ones are redundant in terms of services rendered

(G. Bell, pers comm).

Both points of view (intrinsic and anthropocentric) need not be contradictory, as they serve the same ultimate purpose. Yet they often are considered incompatible because they stem from two very different philosophies: one which views nature as innately valuable and one that regards it as economically valuable.

Both the intrinsic value and the anthropocentric values are presented in this page. The debate regarding the value of biodiversity and the need to protect it is still very hotly contested. The reader is left to draw their own conclusions from the arguments presented.


Intrinsic Value

The first argument for the intrinsic value of biodiversity is the idea that humans are part of nature.

"We know now what was unknown to all the preceding caravan of generations: that men are only fellow-voyagers with other creatures in the odyssey of evolution... Above all we should, in the century since Darwin, have come to know that man, while now captain of the adventuring ship, is hardly the sole object of its quest, and that prior assumptions to this effect arose from the simple necessity of whistling in the dark." - Aldo Leopold, A Sand County Almanac.

The argument for conservation of biodiversity often emphasizes the need to facilitate continued evolution. As humans are and were part of nature, they benefited from the evolutionary process. The tenet that humans are part of nature questions whether humans should endanger their own milieu and the process from which they stem.

A corollary to the above argument is reflected in the Noah principle , named for the biblical Noah who saved one pair of every creature on earth in the Ark, which argues that the usefulness of a species is not considered when discussing its conservation, but rather its very presence in the long history of evolution is sufficient to warrant its preservation.

"The non-humanistic value of communities and species is the simplest of all to state: they should be conserved because they exist and because this existence is itself but the present expression of a continuing historical process of immense antiquity and majesty. Long standing existence in Nature is deemed to carry with it the unimpeachable right to continued existence" D.Ehrenfeld, Conserving Life on Earth 1972

Environmental ethicists also stress that humans should protect biodiversity because they are the cause of most of the loss of biodiversity through loss of habitat, overexploitation and other perturbations.

"99 percent of all species that ever lived are now extinct. But I think we have an obligation, now, in our generation and in foreseeable generations, to try to protect every species, try to maintain every species, because virtually every species that is going extinct now is going extinct due to human activity not because of natural processes" R. Noss, 1996

(Takacs, 1996)

Ethics and environment: extension of rights to species and landforms

While many people will challenge us with the notion that protection of the environment is morally good, philosophy and religion have not incorporated the concept of nature conservation; it is not yet included in our ethical framework. The process of inclusion of these issues is one of social evolution. The concept of stewardship, however, is one firmly ensconced in the Judeo-Christian doctrine.

Some people suggest that the idea of biodiversity reaches towards oneness, toward a unity of all living and non-living things. When anthropocentric attempts at valuing biodiversity are put aside, what remains are the realm of the emotional, spiritual and religious justifications. However, skeptics counter that the spiritual and religious holds of biodiversity on humans may simply be due to our lack of understanding of it. (Takacs, 1996 , p. 98)

The noted Harvard biologist E.O. Wilson champions the idea that love of nature has been "hardwired" into us by natural selection. The religious feelings that the concepts of biodiversity and nature can arouse in some can be seen as a natural extension of a tendency to focus on life and lifelike processes. Wilson coined this idea "Biophilia"

It is pointed out that humans, while removed from nature, still need to be surrounded by nature and they respond to this fundamental need by visiting natural parks and bringing nature into their daily lives with pets and plants. But can this apparent love for nature be interpreted as love for biodiversity? Indeed, the notion of biophilia is often countered by the perception that humans want the nature surrounding them to be managed and artificial - green lawns and no pests - not natural and diverse.

(A great reference for more information is a book entitled The Idea of Biodiversity by Takacs, 1996)


Anthropocentric Value

While intrinsic arguments for protection of biodiversity are compelling, it is ultimately arguments of human benefit that pragmetic conservationists find most appealing: as humans, we are inextricably and wholly dependent on this diversity of living things for survival.

Biodiversity, encompassing genetic diversity, species, populations, communities and ecosystems, and landscapes and regions, provides countless benefits to humans at all these scales. Some of these benefits include:

Economic benefits, both direct and indirect;

Aesthetic benefits;

Scientific and ethical knowledge;

Insurance against the future

Economic benefits

The notion that biodiversity has provided us with many benefits is well understood. Some of these benefits come in the form of goods that can be directly valued and costed because they provide something that can be extracted and sold. These goods include everything from all the domesticated agricultural crops that form the basis of the world's food supply, to medicines that protect and cure us to the fibres that make up the clothes we wear. Thus biodiversity is widely valued as food pantry, genetic storehouse for biotechnology and a place to retreat to when we need to get away from our hectic urban existence.

Biodiversity also provides critical indirect benefits to humans that are difficult to quantify because we have never had to put a price tag on them. These benefits encompass ecosystem services , such as air and water purification, climate regulation, and the generation of moisture and oxygen. A group of ecologists who recently attempted to quantify the price of replacing these ecosystem services calculated that they would cost over $3 trillion. That's greater than the entire global GNP! In other words, the world cannot afford to replace these services, therefore we must work to protect our ecosystems.

Natural communities maintain proper gaseous concentrations in the atmosphere and prevent rapid climate changes. Drastic changes in the Earth's atmosphere can have catastrophic effects. Such changes are believed to have led to the disappearance of dinosaurs from Earth 65 million years ago. Much less drastic changes resulted in several global ice ages, the last of which ended 10 thousand years ago.

Vegetation helps recycle moisture into the atmosphere. A single corn plant (1 lb dry weight) can transfer 60 gallons of water from soil to atmosphere in a few months. A single rainforest tree, in its 100 year lifespan can transfer approximately 2.5 million gallons from soil to air. Their role in the hydrologic cycle is crucial.

A multiplicity of organisms is required to create soils and maintain fertility through complex cycles and interactions. Plant roots break up rock to create soil particles, small animals like earthworms, mites, insects and millipedes help give soil its texture and fertility and are crucial to its aeration. Even tinier soil microorganisms and fungi are responsible for cycling essential nutrients like nitrogen, phosphorus and sulfur and making them available to higher plants. And their numbers are staggering. A gram of fertile agricultural soil may contain 2.5 billion bacteria, 400 000 fungi, 50 000 algae and 30 000 protozoa. All these organisms have particular functions and interact with each other and with their physical environment to create the fertile soil that humans depend on for agricultural production.

Natural ecosystems also help absorb the wastes we create and render them nontoxic. Wetlands are large filters which purify freshwater and remove heavy metals and other contaminants from it. We often depend on rivers to flush away and break down the sewage and effluents that we put into them, which again depends on the array of small and large organisms that decompose and transform wastes in water. Soil organisms can slowly decompose food items, paper products and other wastes produced by human activities. (Erlich and Erlich, 1992)

Economic arguments for protecting biodiversity are criticized for being too utilitarian and human-centered. Indeed, an excessive emphasis on the economic values of different species is seen as dangerous for two reasons: there is bias towards the protection of species and ecosystems that have attributable economic value and this perspective may also lead to the conclusion that ecosystems that are not directly benefitting humans are worth more to humans developed than undeveloped.

Aesthetic value and recreation

In North America, protected wild areas where indigenous organisms live undisturbed give people a sense of satisfaction in knowing that there are bears and wolves and rare plants and insects that still exist on their continent. Natural and wild landscapes are aesthetically pleasing and provide opportunities to get away from human-dominated landscapes. They also provide opportunities for recreational activities such as hiking, canoeing, birdwatching and nature photography.(Erlich and Erlich, 1992)

This argument is criticized for two reasons: first, aesthetic value is not necessarily equated to biodiversity; some of the most aesthetically pleasing landscapes are poor in diversity of habitats and species (e.g. mountains) while some unspectacular landscapes are incredibly rich in biodiversity (e.g. swamps and wetlands). Second, this aesthetic argument is relevant only to a minority of wealthy citizens in developed countries and holds little relevance to the majority of the world's population

(Takacs, 1996)

Future potential

While there are hundreds of examples of known economic and aesthetic benefits of biodiversity, biologists and other scientists frequently outline that more is unknown than known. Important ecosystem services and uses for plants and animals are still unknown and await discovery. Yet these cannot be discovered, and benefit humankind, if they disappear before discovery. The threat to biodiversity can be compared to book burning (the obliteration of former and future knowledge).

Many of our valuable goods, from spices (cinnamon, pepper) to critical medications (aspirin, tamoxifen, quinine, digitalis) have been discovered "accidentally" because plants or animals produced chemicals for defense or attraction. We would not have otherwise considered the organisms from which these chemicals originated as valuable and worthy of conservation.


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Part 1: Components of Biodiversity


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Part 3: Patterns and Processes of Biodiversity