Humans in the Bioshpere

Historical Humans in the Biosphere Hunting and Gathering Most of human history

Agriculture - farming Started about 11,000 years ago (after last

ice age)

Humans started changing the Earth somewhat

Modern agriculture 1800s & 1900s – science and technology

started to increase agricultural yields

Monoculture – large fields are planted with a single variety of plant year after year

Historical Humans in the Biosphere The Green Revolution Technology lead to the development

of large yields to help human need for food with increasing population

Challenges for the Future Monoculture leads to increases of

pests and disease

Enough water for irrigation

Protect natural resources

Urban Development Various issues with dense

populations: food production & transportation, waste, water supply, etc.

Renewable & Non-Renewable Resources A renewable resource can be

replaced by a living thing or biochemical cycles

Trees, water, sun, etc.

A non-renewable resource cannot be replaced by living processes in a reasonable amount of time

Coal, oil, natural gas (fossil fuels)

Sustainable Development Idea of using natural resources without depleting them and

providing for human needs without causing long term environmental harm Replanting forests Cleaning up water supplies Leave no trace Restrictions on travel/hiking, etc.

Land Resources There needs to be room for stuff to grow Soil erosion – the wearing away of surface soil by water and wind

Plowing

Desertification – a combination of farming, overgrazing, and drought in dry areas turn productive land into deserts Sahara

Land pollution Trash – the average American produces about

1.8 kg of solid waste daily – 657 kg/yr Destroy habitats and pollute areas

Pesticides, etc. can also lead to habitat degradation DDT

Forest Resources Wood, medical supplies, habitats

for animals, recreation, etc.

Deforestation

Done for farmland, development, paper, etc.

Can lead to severe erosion, lack of clean air, changes in microclimates

Forest Management

Selective cutting, replant trees, faster growing trees

Fishery Resources Fish are a valuable source of food for

humans

Overfishing decreases supplies and makes for an increased population recovery time

Sustainable Development

Limits

Aquaculture – raising of aquatic animals for human consumption

Air Resources Smog – mixture of chemicals that occurs as a gray-

brown haze in the atmosphere

Mostly from automobile exhaust

Threatens health of people – especially young, old, and asthmatics

Acid Precipitation – sulfur dioxide from burning coal and nitrogen oxides from automobile exhausts combine with water vapor Leaches calcium, potassium and other nutrients

from the soil Damages plant tissues Alters pH of lakes

Ozone layer damage – CFC’s break down 03

Increased skin cancers Possible cause for amphibian population decreasing

Water Resources We need clean water to drink, provide habitats for food,

grow crops, etc.

Fertilizers and animal wastes carried by runoff Causes algal blooms

These algae die, decay and remove oxygen from the water

Silt from erosion clogs gills, blocks sunlight

Detergents, metals, industrial chemicals from runoff

Debris in oceans and lakes

Gyres

Biological Diversity Biodiversity refers to the variety of life in an area

Most common measure is the number of species that live in a certain area

Terrestrial biodiversity tends to increase as you move towards the equator

2/3 of all land species on Earth are in tropical regions

The areas richest in any type of biodiversity are warm regions

Rain forests, coral reefs, tropical lakes

The size of the area also affects biodiversity

Larger areas tend to be more diverse (unless other things prevent or encourage life)

Importance of Biodiversity Organisms are adapted to live together in a

community If you take one away, there are consequences to the rest

Biodiversity brings stability to an ecosystem More resources, interactions, etc.

Biodiversity is important to humans Oxygen to breath, remove CO2

Diverse diet / Better crops (resistance)

Building materials

Possible pharmaceuticals

Wo l ves

Loss of Biodiversity Extinction – the disappearance of a species when

the last of its members dies

Since 1980, almost 40 species of plants and animals have gone extinct in the U.S.

Can be natural or human-caused

Threatened Species – when the population of a species begins declining rapidly

In the US: sea otters, loggerhead turtles, bald eagle

Endangered Species – population numbers so low that extinction is possible

In the US: California Condor, Florida manatees

Threats to Biodiversity Habitat loss – the biggest threat

Take away resources for life

Habitat fragmentation – separation of wilderness areas from other wilderness areas

Roads – leads to less biodiversity

Animals that migrate or need large areas to hunt

Climates can change (take away shade)

The Edge Effect

The different conditions along the boundaries of an ecosystem

Threats to Biodiversity Introduction of Exotics

Exotic species – organisms that are not native to a particular area

Can grow at an exponential rate due to a lack of competitors and a lack of predators

Take over niches of native species Sea lamprey in Great Lakes after Erie Canal

Goats on Santa Catalina Island

Greenhouse Effect

The capacity of certain gases in the atmosphere to trap heat emitted from Earth’s surface, thereby insulating and warming the planet.

Without the thermal blanketing of the natural greenhouse effect, Earth’s climate would be about 33°C (about 59°F) cooler—too cold for most living organisms to survive.

Global Climate Change Nickname is global warming

Greenhouse Gases

1. Water vapor – not much control here

2. Carbon dioxide – respiration, burning

Pre-industrial revolution – 280 parts per million in atmosphere

2007 – 385 ppm

3. Methane – mining, rotting organic material, melting permafrost

Traps 30 times more heat than CO2

Doubled in atmosphere since industrial revolution

Global Climate Change

Nitrous Oxide – plowing farm soils and burning fossil fuels Traps 300 times more heat

than CO2

Increased 18% since before industrial revolution

Ozone – automobiles

Good up high, contributes to smog down low

Others – CFCs, aerosols All human produced

Global Climate Change In 1988 the United Nations Environment Program (UNEP) and the

World Meteorological Organization (WMO) established the Intergovernmental Panel on Climate Change (IPCC). The panel comprises thousands of the top climate scientists from around the world and releases a report every six years describing the state of scientific knowledge on global warming. The IPCC’s Fourth Assessment Report, released in 2007, offered the strongest scientific consensus to date on global warming. The panel concluded that it is “very likely” (more than 90 percent probability) that human activities are responsible for most of the warming since the mid-20th century; that it is “extremely unlikely” (less than 5 percent probability) that the warming is due to natural variability; and that it is “very likely” the warming is not due to natural causes alone. This level of certainty is extremely high, given the complexity of the climate system and of the influence of human activities on the climate.

Section 1 Review1. What are two reasons for a species to become

threatened or endangered?

2. Explain how land that gets broken up can contribute to loss of species diversity.

3. What is an edge effect? Explain how changes in an ecosystem’s edges can affect organisms.

4. How can exotic species affect populations of native species?

Conservation Biology Conservation Biology is the study and implementation

of methods to protect biodiversity.

Natural resource conservation - natural resources are those parts of the environment that are useful or necessary for living organisms.

Species conservation - protecting species from extinction and preserving biodiversity

MY FOOTPRINT

Legal Protection of Species 1973, the U.S. Endangered Species Act made it

illegal to harm any species on the endangered or threatened list

Illegal for federal agencies to fund any project that would harm these species

The Convention on International Trade in Endangered Species (CITES)

Established lists of species for which international trade is prohibited or controlled

Honored by 120 countries

Preserving Habitats One way is to create national

parks

First one in US was Yellowstone

Originally this was to preserve the geology

Protects natural environments and provides habitats for many organisms

Habitat Corridors Protected strips of land

that allow the migration of organisms from one wilderness to another

Isolated populations inbreed too much

Wilderness Areas

http://www.nationalatlas.gov/natlas/Natlasstart.asp

Utah

Sustainable Use In National Parks, the land is managed

This philosophy strives to enable people to use natural resources in ways that will benefit them and maintain the ecosystem Some grazing

Harvest fruits

Hiking, camping, etc.

Preservation Programs Captive Breeding followed by

Reintroduction Programs

Release organisms into area where the species once lived

Ex: black-footed ferret

Ex: brown pelican after DDT

Seed banks for threatened and endangered plant species

Bighorn Sheep They are being

reintroduced to historical ranges in Utah

Gone in the 50s – 60s from everywhere but Colorado River corridor Habitat degradation, predation,

disease

30% of reintroductions successful nationwide, 50% in Utah Problems arise because their

habitat right next to an Urban area with 300,000 people What is that called?????

Disease from sheep causes lots of death

What Can I Do?1. Switch to compact fluorescent bulbs

2. Set thermostat to 55°F when sleeping

3. Set water heater temperature to 130°F

4. Choose seafood wisely

5. Buy EnergyStar appliances and electronics

6. Wash and rinse laundry in cold water

7. Buy locally produced food and produce

8. Drink from reusable glassware

9. Walk, bike, and carpool

Section 2 Review1. Describe the U.S. Endangered Species Act.

2. Why is it difficult to reintroduce species that have been captive bred?

3. What is sustainable use and how does it influence Utah?

4. What are 2 different types of preservation programs?