Human Impact and the Environment

Chapter 22

Earth’s Layers

• Geosphere• Hydrosphere• Atmosphere

• Biosphere

Biodiversity

• Species diversity– Species richness– Species evenness

How do you study these factors?

Are they equally important?

• Genetic diversity– Affects a

populations ability to adapt when faced with environmental change.

Benefits of Biodiversity

• Why is your quality of life impacted by the extinction of species?

Environmental Issues

• Pollution– Smog

• Nitrogen oxides, sulfur oxides, organics, ozone

– Ozone thinning• CFC’s deplete ozone• Could lead to new cases of skin cancer

– Global warming• A complex issue.

Ozone Layer

• What is it?• Why is it

important?• What factors

seems to affect the ozone layer?

• Acid Precipitation

• Land and Water Pollution– Biological magnification

• Everyone’s problem

Bald Eagles and Lead Poisoning--Biomagnification

Ecosystem Disruption

• Extinction

Tasmanian Tiger

Passenger Pigeon

Quagga

Ecosystem imbalances

• Some species are critical to the functioning of ecosystems.

• These species are called keystone species.

– Ever built the arch at the Science Center?

– Can the arch stand without the keystone?

– Keystone species• Prairie Dogs have long been vilified by

ranchers and others who believe that they damage the range and take valuable forage away from cattle and other livestock. In fact, prairie dogs are what is known as a keystone species, a species whose very presence contributes to the diversity of life and whose extinction would result in the extinction of species dependent on it.

The grazing and burrowing activities of prairie dogs improve forage quality, conserve water and improve soil

Human Resource Use

• Human’s use 55% of the primary production of the Earth

• Ecological footprint: human impact on ecosystems

• Sustainability: the ability to meet human needs in such a way that a human population can survive indefinitely. (what is the Earth’s

Carrying Capacity?)

Environmental Solutions

• Conservation Biology: identify, protect and manage areas that still have biodiversity.

• Restoration Biology: repair damaged ecosystems (have you seen the “Prairie Restoration” signs on the highway?)

• Species and Habitats– Bioindicators: species that are very

sensitive to environmental change.

Ex. Amphibians,

Whooping Crane

• In 1935 only about 15 individuals left.

• 2011 census indicates around 600 individuals.

• Is this a conservation success story?

Protecting EcosystemsBiodiversity Hotspots

Regions richest in biodiversity but in need of protection.

• Governments and Laws: protect endangered species, set aside land to protect habitats, clean up pollution, regulate destructive activities such as mining.

• Ecotourism: a way for developing countries to protect their biodiversity.

Urban Ecology.

• What can you do?

• What do you do?