1. Humans in the Biosphere
Chapter 6

2. A Changing Landscape Human activities
Among human activities that affect the biosphere are hunting and gathering, agriculture, industry, and urban development
Human participate in food web and chemical cycles
Human change the local and global environments

3. A Changing Landscape Hunting and gathering
people who obtain food by collecting and hunting wild animals.
Some scientist hypothesize that 12,000 years ago caused major extinction.
Example – woolly mammoths, saber-tooth cats

4. A Changing Landscape
Agricultural Revolution – When hunters and gathers started collecting seeds to plant and domesticating animals.
agriculture provides human society with fundamental needs
dependable food supply
large quantity of food
Storage for excess food

5. A Changing Landscape
Monoculture – large fields planted with one type of crop
Fertilizer – chemical or natural boost for plant growth
Pesticide – chemical or natural controls for pest or insects
Green revolution – the use of genetic hybrids, monoculture and chemical fertilizers the increased world food supply
Challenges for the future
More insects
More pesticides – kill good insects, produce runoff, contaminate water supply
Irrigation

6. A Changing Landscape
Industrial revolution – the shift from animal muscle to energy provided by water and fossil fuels which brought about sophisticated machines.
Pros – mass production of materials, more advanced machines, more mobility, advance medicine
Cons – air pollution, soil pollution, water pollution, waste disposal.
Pollution – An undesired change in air, water or soil that adversely affects the health, survival, or activities of humans

7. Renewable and Nonrenewable Resources
Natural resources – any natural material used by humans
Renewable resource – sources that can be replaced. Give some examples!
Nonrenewable resourced – a resource that is consumed at a faster rate than replenished.

8. Renewable and Nonrenewable Resources
Sustainable development – a way of using natural resources without depleting and providing for human needs without causing long term environmental harm
Humans affect quality and supply of all resources

9. Renewable and Nonrenewable Resources
Land resources – provide space for human communities and raw material humans need
Food grow best in fertile soil made up of a mixture of sand, clay, rock particles and humus
Plowing of soil remove roots that hold soil together
Soil erosion – wearing away of soil by wind or water
Desertification – the process where over farming and dry conditions turn a once productive area into a desert
Ways to keep it from happening
Leave stems and roots from previous crop on farmland
Sowing a fast growing cover - rye

10. Renewable and Nonrenewable Resources
Forest resources – important resource for products they provide and the ecological functions they perform
Wood is used for fuel and building material
Forest can
provide nutrients
Provide habitat
Limit soil erosion
Moderate climate
Protect fresh water supply
Deforestation – loss of forest
Species can be lost
Severe erosion
Change soil and microclimates

11. Renewable and Nonrenewable Resources
Fishery Resources
Fishes and other animals that live in water are valuable source of food
Over fishing – harvesting fish faster than they can reproduce
Declining of fish is an example of the tragedy of commons
Over use of and area
Fisheries help replenish this resource
Sustainable Development – regulations that help the fish pollution to recover.
Guidelines can specify how many fish and what size of fish can be caught in a given area
Aquaculture – the raising of aquatic organisms for human consumption
Helps sustain populations

12. Renewable and Nonrenewable Resources
Air Resources – resources the air provides organisms
Oxygen, carbon dioxide, nitrogen
Condition of air affects people
Smog – mixture of smoke and fog usually found in highly populated regions
Pollutant – harmful material that can enter the biosphere through the land, air or water
Acid rain – rain with high acidity. Caused by burning of fossil fuels that release sulfuric and nitric acid into the air.

13. Renewable and Nonrenewable Resources
Freshwater Resources
Water is a renewable resource but freshwater is limited
Major priority must be given to protect freshwater from pollution.
Protecting wetlands
Protect forest \protect swamps
Prevent soil pollution

14. Biodiversity
Biodiversity – the sum total of the genetically based variety of all organisms in the biosphere
Ecosystem diversity – the variety of habitats, communities, and ecological processes in the living world
Genetic diversity – the total sum of all the genetic information carried by all the organisms on earth
Biodiversity is one of the earth’s greatest resources.
Species of many kinds have provided us with food, industrial products, and medicine.

15. Biodiversity Threats to biodiversity Hunting species to extinction
Introducing toxins
Introducing foreign species to new areas
Altering habitats
Extinction – when a species disappears from all or part of it’s range
Endangered species – species population size declines to almost extinction
Habitat fragmentation – splitting of ecosystems into pieces
Development of farms or communities

16. Biodiversity
Pollution