Conservation Biology and Restoration Ecology

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Biodiversity and Human Welfare

Human biophilia allows us to recognize the value of biodiversity for its own sake.

Species diversity brings humans practical benefits. The enormous genetic diversity of organisms has potential for great human benefit.

In the United States, 25% of prescriptions contain substances originally derived from plants.

For example, the rosy periwinkle contains alkaloids that inhibit cancer growth.

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The rosy periwinkle, a plant that saves lives

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Ecosystem Services

Ecosystem services encompass all the processes through which natural ecosystems and their species help sustain human life.

Some examples of ecosystem services:

Purification of air and water

Detoxification and decomposition of wastes

Cycling of nutrients

Moderation of weather extremes.

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Three Threats to Biodiversity

Most species loss can be traced to three major threats:

Habitat destruction

Introduced species

Overexploitation

Human alteration of habitat is the greatest threat to biodiversity throughout the biosphere.

In almost all cases, habitat fragmentation and destruction lead to loss of biodiversity.

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Introduced Species

Introduced species are those that humans move from native locations to new geographic regions.

Without their native predators, parasites, and pathogens, introduced species may spread rapidly.

Introduced species that gain a foothold in a new habitat usually disrupt their adopted community.

Sometimes humans introduce species by accident, as in case of the brown tree snake arriving in Guam as a cargo ship “stowaway.”

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Overexploitation

Overexploitation is human harvesting of wild plants or animals at rates exceeding the ability of populations of those species to rebound.

Overexploitation by the fishing industry has greatly reduced populations of some game fish, such as bluefin tuna.

DNA analysis can help conservation biologists to identify the source of illegally obtained animal products.

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Overexploitation

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Population conservation focuses on population size, genetic diversity, and critical habitat

Biologists focusing on conservation at the population and species levels follow two main approaches: