STS biodiversity & conservation quiz

Biodiversity

the variety of life within a particular habitat, often measured by the number of different species

Three measures of life’s variations

species diversity, genetic diversity, ecosystem diversity

Species diversity

the number of different species in a particular ecosystem or on Earth

Genetic diversity

differences among individuals or populations; variation within a species

Ecosystem diversity

the many types of functional units formed by living communities interacting with their environments

Keystone species

an organism that others may depend on for survival

Species interdependence

the degree to which different species in a given ecosystem, or area, depend on other species in that area for survival

Main reason for decline in biodiversity and extinction

habitat destruction

Economic benefits of biodiversity

• Wild plants and animals maintain a valuable pool of genetic variation. This is important because domestic species are genetically uniform. This puts them at great risk of dying out due to disease.

• Other organisms provide humans with many different products. Timber, fibers, adhesives, dyes, and rubber are just a few.

• Certain species may warn us of toxins in the environment. When the peregrine falcon nearly went extinct, for example, it warned us of the dangers of DDT.

• More than half of the most important prescription drugs come from wild species. Only a fraction of species have yet been studied for their medical potential.

• Other living things provide inspiration for engineering and technology.

Ecosystem services of biodiversity

• Plants and algae maintain the atmosphere. During photosynthesis, they add oxygen and remove carbon dioxide.

• Plants help prevent soil erosion. They also improve soil quality when they decompose.

• Microorganisms purify water in rivers and lakes. They also return nutrients to the soil.

• Bacteria fix nitrogen and make it available to plants. Other bacteria recycle the nitrogen from organic wastes and remains of dead organisms.

• Insects and birds pollinate flowering plants, including crop plants.

• Natural predators control insect pests. They reduce the need for expensive pesticides, which may harm people and other living things.

Rule of 10 percent in energy transfer

Only a small fraction of energy available at any trophic level is transferred to the next trophic level. That fraction is estimated to be about 10 percent of the available energy. The other 90 percent of the energy is needed by organisms at that trophic level for living, growing, and reproducing.

Compare the strengths of a food chain model versus a food web model for representing feeding relationships in an ecosystem.

Food chain

• illustrating a single, direct path of energy flow

• showing a sequence of who eats who

Food web

• illustrating the complex, interconnected feeding relationships and multiple energy pathways within an ecosystem

• predicting how the change in one population will affect many other populations it’s connected to

Sixth mass extinction

current rapid rate of species abruptly disappearing from Earth that is due mainly to human destruction of habitats

Causes of extinction

exotic species, over-harvesting, global climate change (largely due to the burning of fossil fuels), pollution, human overpopulation

Habitat loss

destruction or disruption of Earth’s natural habitats, most often due to human actions such as agriculture, forestry, mining, and urbanization

Exotic species

species that is introduced (usually by human actions) into a new habitat where it may lack local predators and out-compete native species

How did the accidental introduction of the brown tree snakes to Guam affect the island’s native ecosystem?

Lacking local island predators, this exotic species of snakes multiplied quickly. They have already caused the extinction of many birds and mammals they preyed upon in their new island ecosystems.

Effects of extinction

• Fewer cougars in the western US state of Utah led to an explosion in the deer population. The deer ate more vegetation, which altered the path of local streams and lowered overall biodiversity.

• In Africa, where lions and leopards are being lost to poachers, there is a surge in the number of olive baboons, who are transferring intestinal parasites to humans living nearby.

• In the oceans, industrial whaling led to a change in the diets of killer whales, who eat more sea lions, seals, and otters, and have dramatically lowered the population counts of those species.

How individuals can help protect biodiversity

consume wisely, avoid plastics, go organic, save energy

Explain the HIPPO acronym and what each letter means in the context of major threats to biodiversity.

It represents five of the biggest threats to biodiversity.

H: Habitat loss, I: Invasive species, P: Pollution, P: Population growth, O: Overharvesting

Conservation

aims to maintain the biodiversity of a particular ecosystem

Ex-situ (off site) conservation

Individuals of an endangered species are removed from their natural habitat and placed in a new secure location where their needs for survival are met (zoos, aquaria, botanical gardens).

Disadvantages of ex-situ conservation

expensive, labor intensive, limited genetic diversity, difficulty in adaptability

In-situ (on site) conservation

the conservation of a species in its natural environment

Disadvantages of in-situ conservation

ecological restoration, population decline, difficulty in controlling illegal poaching