1. Humans and The Environment

2. Concept Map Human Activities Section 6-1 Hunting and gathering
that have changed the biosphere include
Hunting and
gathering
Agriculture
Industrial
growth
Urban
development
may have once caused
often relies on the methods of the
have resulted in
Extinctions of
large animals
Green
revolution
High standard
of living
Increased
pollution
which increased
Food supply
Pesticide use
Monoculture
use
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3. Leaving a Mark on the World
Interest Grabber
Leaving a Mark on the World
Section 6-1
Have you ever seen very old photographs of the town or city in which you now live? Has your area changed? Perhaps there are more buildings or roads than there were many years ago. Maybe your town or city has more trees and flowers now than it had years ago. Humans, like all organisms, have an effect on their environment.
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4. Earth is a kind of island
Limited resources
Nature must sustain the resources
Human populations is growing
The planet is not

5. Demands on
Air
Water
Land
Living things

6. We must protect these resources
What human activities do you think have an impact on the earth’s natural resources?
Hunting and gathering
Agriculture
Industry
Urban development

7. Recent study concluded that human activity uses as much energy as all of earth’s other multicellular species combined
Humans are the most influential in changing the environments of the planet

8. HUNTING AND GATHERING
Hunting and gathering has been the primary means of human survival for most of human history
Fished, gathered seeds, fruits, and nuts
Lived in small groups

9. Early man
Built dams
burned grasslands to encourage growth of certain plants

10. Some scientists hypothesize that humans are responsible for the mass extinction of
woolly mammoths
giant ground sloths
sabertooth cats\
cheetahs
zebras
yaks

11. Agriculture
Early humans learned how plants grew, which were edible, and which were good medicines
They began to plant those that were important near their settlements
11,000 years ago, humans started farming (Agriculture)

12. Agriculture Agriculture spread
With dependable food supply, people started living in larger settlements – towns and cities
Domestication of Animals
Over time, people started keeping herds of domesticated animals

13. List 3 reasons people keep animals

14. Agriculture Milk, meat, hides, wool, companionship, perform work
Overgrazing changed grasslands ecosystems – eroded soils, large demand on water
Human population grew at an increasing rate.

15. Green Revolution By 1950’s food supply was straining
Green Revolution – to increase food supply, governments and scientists introduced new farming techniques to increase yields of crops (rice, wheat, corn)
Relied on new, highly productive strains of crops

16. Green Revolution
Monoculture – large fields plowed, and planted with a single crop year after year
Irrigation, fertilization, and pesticides were relied on to sustain the crops
Animal and human power was replaced with machine power
Within 20 years, Mexican farmers increased production of wheat 10 times

17. Green Revolution
Problems have been introduced by the green revolution. Can you name a few?
Depletion of water supplies
Pollution of water by pesticides and fertilizers

18. Industrial growth and Urban Development
Wastes from manufacturing and energy production have been poured into the air, water, and soil
Tied to high standard of living that we all enjoy

19. The question is: How do we control the harmful effects of human activity on the environment?

20. Tragedy of the Commons
Resource is something that can be used to take care of a need
When an environmental resource is owned by many people, or no one, but no one is responsible for it, it is called a “common resource”.

21. Tragedy of the Commons
The Tragedy of the Commons – any resource open to everyone will eventually be destroyed because although everyone owns the resource, no one is responsible for it.
Air, Water – shared by many countries, but no one is responsible.

22. Whaling – if some countries attempt to protect whales, but others continue to hunt whales to extinction, what will eventually happen?

23. 2 types of resources – Renewable and Nonrenewable
Renewable resources can be regenerated (but not necessarily limitless)
Sunlight
Fresh water
A tree
Fish

24. 2 types of resources – Renewable and Nonrenewable
Nonrenewable – cannot be replenished by natural resources
Fossil fuels
Coal
Oil

25. Interest Grabber continued
Section 6-2
1. Examine the list of natural resources shown below. Then, classify each natural resource as either renewable or nonrenewable.
a. Wood
b. Fossil fuels
c. Aluminum
d. Wool
e. Gold
2. Describe the impact that the loss of nonrenewable resources would have on the environment.
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26. Where Do Natural Resources Come From?
Interest Grabber
Section 6-2
Where Do Natural Resources Come From?
Natural resources are materials that are supplied by nature. A renewable resource is one that is replaceable. A nonrenewable resource is one that cannot be replenished by natural processes. Once a nonrenewable resource is used up, it is gone forever.
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27. Land Resources Land is a resource
Provides space for living, raw materials for building, and industry
Important for soils crops grow on

28. Land Resources
Soil is a renewable resource that can be damaged by human activities
Best fertile soil is a mixture of humus, sand, clay, and rock particles

29. Most of the humus is in the top layers called “Topsoil”
Absorbs and retains moisture, but allows drainage
Lots of nutrients
Low in salts

30. Different plants add and use different amounts of nutrients
Plowing the land removes the roots that prevent erosion
Erosion – the wearing away of the surface soil by water and wind
Combinations of farming, overgrazing, and drought can cause productive areas to become deserts
Process is desertification

31. Practices that can maintain the soil include
Contour plowing
Planting crops that maintain the soil while primary crops are harvested – rye for example
Leaving roots and stems of previous year’s crops

32. Sustainable Agriculture
Section 6-4
Cover Crops
Legumes, grasses, and other
cover crops recycle soil nutrients,
reduce fertilizer need, and
prevent weed growth.
Controlled Grazing
By managing graze periods and herd
densities, farmers can improve nutrient
cycling, increase the effectiveness of
precipitation, and increase the carrying
capacity of pastures.
Biological Pest Control
The use of predators and parasites
to control destructive insects
minimizes pesticide use as well as
crop damage A B C
Contour Plowing
Contour plowing reduces
soil erosion from land runoff.
On hilly areas, plowing is done
across the hill rather than
straight up and down.
Yr. 1
Crop Rotation
Different crops use and
replenish different nutrients.
By rotating crops, the loss
of important plant nutrients
is decreased.
corn
oats
alfalfa
Yr. 2
alfalfa (plowed in)
corn
alfalfa
Yr. 3
oats
alfalfa
corn
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33. Forest Resources Forests provide Wood Paper Fuel Remove CO2 and add O2
Food
Sore nutrients
Moderate climate
Limit soil erosion
Protect fresh water supplies

34. Forest Resources Deforestation – Loss of forests
Soil erosion – topsoil and nutrients washed away
Grazing and plowing after deforestation can add to problems
Sustainable use strategies
Harvesting mature trees selectively
Plant, manage, harvest, and replant tree farms
Geneticists breeding faster growing varieties

35. Ocean Resources
Food
Fish catch has risen from 20 million tons/year to over 90 million tons / year
As fish catches rose, fish stocks declined
Overfishing
Techniques to moderate include
Limits
Aquaculture
Temporary closing of areas to fishing

36. Amount of Fish per Person
Growth of Fish Catch
Section 6-2
World Fish Catch
World Fish Catch per Person
Total Catch
(million tons)
Amount of Fish per Person
(kilograms)
Year
Year
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37. Air Resources Air is a resource – we breath it Smog – smoke and fog
Auto and industrial exhaust include Nitrogen oxides and sulfur dioxides that are transformed into nitric and sulfuric acids
Cause acid rain
Pollutant – a harmful material that can enter the biosphere through land, air, or water
Acid rain can kill plants, and cause soil chemistry to change
May release Hg, or other dissolved toxic elements

38. Chemical Transformation Emissions to Atmosphere
Figure 6-12 The Formation of Acid Rain
Section 6-2
Chemical Transformation
Nitric acid
Sulfuric acid
Condensation
Emissions to Atmosphere
Nitrogen oxides
Sulfur dioxide
Dry Fallout
Precipitation
Acid rain, fog,
snow, and mist
particulates, gases
Industry
Transportation
Ore smelting
Power generation
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39. Water Resources Water is a resource
Drinking, washing, watering crops, industry
71% of the earth is covered by water
97% of the water is sea water (salty)
2% more is frozen
1% of all water is liquid fresh water

40. Pollution Wastes discarded (on purpose or not) can
Seep into water supplies
Sewage
Contains nitrogen and phosphorus
Cause algal and bacterial growth
Spread disease

41. Pollution
Wetlands such as swamps and estuaries can help to protect water supplies
Purifies water as it passes through
Holds soil in place

42. What Is Biodiversity?
Interest Grabber
Biodiversity is the sum total of the variety of organisms in the biosphere. Sometimes humans can reduce biodiversity, which is considered a natural resource.
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43. Biodiversity 1.5 million species identified so far Food
medicine – painkillers, heart drugs, antibiotics
industrial products

44. Species Diversity Insects Protists Other Animals Plants Bacteria Fungi
Section 6-3
Insects
54.4%
Protists
Other Animals
4.2%
19.7%
Plants
18%
Bacteria
Fungi
0.3%
3.4%
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45. Biodiversity Human activity can reduce biodiversity
May cause extinction

46. Biological magnification
Biological magnification– toxins may be concentrated from one trophic level to the next.
DDT is an example
DDT is a pesticide that was used extensively
DDT is not biodegradable
Organisms do not eliminate it

47. Figure 6-16 Biological Magnification of DDT
Section 6-3
10,000,000
Fish-Eating Birds
Magnification of
DDT Concentration
Large
Fish
1,000,000
100,000
Small Fish
10,000
Zooplankton
1000
Producers
Water 1
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48. Biological magnification
Concentrates as herbivores eat plants sprayed with DDT, then carnivores eat the herbivores etc…

49. Introduced species
Organisms transferred from one area to another that did not have them before
Zebra Mussel, Phragmites, Japanese shore crab

50. Interest Grabber continued
Section 6-1
1. Choose an animal other than a human and describe at least two ways in which it may change its environment.
2. What events might have led to the changes that occurred in your town or city?
3. What positive effect have humans had on their environment? What negative effect have humans had on their environment?
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51. 3. What can be done to preserve the biodiversity of organisms?
Interest Grabber continued
Section 6-3
1. List three ways in which other organisms have proved to be a benefit to humans.
2. Compare biodiversity with other natural resources, such as wood and fossil fuels. Do you think biodiversity is a renewable or a nonrenewable resource? Explain your answer.
3. What can be done to preserve the biodiversity of organisms?
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52. Interest Grabber
How Much Should It Cost?
You may have read that when something becomes hard to obtain, its price usually increases. Such is the case for materials like gold and diamonds, which are nonrenewable resources. Using similar thinking, some researchers believe that all the valuable services provided by a healthy ecosystem should be assigned a dollar value.
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53. 1. Fresh, clean drinking water 2. Clean air to breathe
Interest Grabber continued
Section 6-4
Rank the following items in order of their importance to you. Then, next to each item, write down how much you would be willing to pay for it.
1. Fresh, clean drinking water
2. Clean air to breathe
3. An endangered plant containing a substance that can cure cancer
4. Gas for your family car
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54. Figure 6-22 Ecosystem Services
Section 6-4
Solar energy
Production of oxygen
Storage and recycling of
nutrients
Regulation of climate
Purification of water and air
Storage and distribution of
fresh water
Food production
Nursery habits for wildlife
Detoxification of human and
industrial waste
Natural pest and disease
control
Management of soil erosion
and runoff
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