1. Chapter 6: Humans in the Biosphere

2. Section 6.1 : Changing Landscape I. The Effect of Human Activity *How do out daily activities affect the environment? - think about the cultivation of Hawaii:

3. *Many non-native plants and animals were introduced which caused native plants to go extinct. *land was cleared for crops and tourism

4. A. Living on Island Earth 1. Humans rely on Earth’s life-support systems, and we affect our environment when we: a) obtain food b) eliminate waste products c) build places to live 2. Living on an island – can make people more aware of limited resources and carrying capacity b/c the island is small.

5. 3. Living on large continents – due to large land size we often don’t realize that resources are limited. 4. Human activity has altered half of all the land not covered by ice and snow. 5. Humans affect regional and global environments through: a) agriculture

6. b) Development c) Industry

7. 6. This impacts the quality of earth’s natural resources: a) soil b) water c) atmosphere *some suggest that our planet may be nearing it’s carrying capacity @ 7 billion……… which happened on October 31 st, 2011!

8. B. Agriculture 1. Agriculture is one of the most important inventions in human history. 2. Agriculture allowed for settlement, which in turn allowed for civilization which led to government.

9. 3. Monoculture – the practice of clearing large areas of land to plant a single highly productive crop year after year. Ex) soybeans 4. monoculture allows for: a) efficient saving b) tending c) harvesting of crops via machines

10. *trying to provide enough food for 7 billion people can have a large impact on water, fertile soil, and can consume large amounts of fossil fuels. C. Development 1. As modern society developed, many people chose to live in cities.

11. 2. As urban cities became overcrowded people moved to and developed the suburbs. 3. Problems with dense development: a) produce wastes – if not disposed of properly, it can lead to problems w/ air, water, and soil quality. b) consumes farmland – less space to grow crops

12. c) habitat fragmentation – occurs when a habitat becomes divided. D. Industrial Growth 1. Human society was transformed by the industrial revolution of the 1800’s.

13. 2. Many of the advances made by the Industrial Revolution required a lot of energy, much of which came from the burning of fossil fuels; this had dramatic environmental impacts. 3. wastes – many industries release their waste directly into the surrounding air, water, and soil.

14. II. Sustainable Development *goods – things that can be bought and sold; they have value in terms of dollars and cents. *services – processes or actions that produce goods. *ecosystem goods and services – goods and services produced by ecosystems that benefit the economy.

15. A. Ecosystem Goods and Services 1. Some ecosystem goods and services are so basic we take them for granted; ex) breathable air, drinkable water 2. Normally a healthy ecosystem can provide the basic goods and services we need, but if it can’t then society must spend money to provide them ex) drinkable water is provided by rivers, streams, and lakes and is filtered by wetlands; but if these sources are polluted then we must pay to treat the water

16. B. Renewable and Nonrenewable Resources *ecosystem goods and services are classified as either renewable or nonrenewable. 1. renewable resources – can be produced or replaced by a healthy ecosystem, ex) a tree; new trees can grow from it

17. 2. Nonrenewable Resources – resources which cannot be replenished naturally within a reasonable amount of time. Ex) fossil fuels – coal, oil, gas…. Once they are gone they are gone for good!

18. C. Sustainable Resource Use 1. Sustainable Development – using resources in an environmentally conscience way. 2. Sustainable development provides for human needs while preserving the ecosystems that produces natural resources. 3. Sustainable development should a) cause no long-term harm to soil, water, or climate

19. b) consume as little energy and material as possible c) be flexible enough to survive environmental stress such as floods, fires, droughts, etc. d) take into account human economic systems as well as ecosystem goods and services *It must help people to improve their situation

20. Section 6.2 : Using Resources Wisely *How do we find balance? How do we obtain what we need from local and global environments without destroying them? I. Soil Resources 1. Many objects you use daily relied on soil at one point: -the grain for your cereal -the paper for your books -wood supports for your homes

21. 2. Healthy soil supports agriculture and forestry. 3. Topsoil – the mineral and nutrient rich portion of soil; it absorbs and retains moisture, but allows excess water to drain. 4. How is good topsoil produced? By long-term interactions between the soil and plants that are growing in it. 5. Topsoil can be renewable if managed properly, but can also be damaged very quickly if not.

22. Ex) Dust Bowl – resulted form years of poorly managed farming and drought in the Great Plains in the 1930’s People lost their jobs and left. Caused in part by the conversion of prairie land to cropland in ways that left the soil vulnerable to erosion.

23. A. Soil Erosion 1. Soil Erosion – is the removal of soil by water or wind; it is often worse when land is plowed and left barren in between plantings. *if no roots are available to hold soil in place it easily gets washed away.

24. 2. Desertification – occurs in dry climate areas; farming, overgrazing, seasonal drought, and climate change can turn farmland into desert. 40% of earth’s land is at risk for desertification.

25. 3. Deforestation – loss of forest; impacts soil quality in a negative manner. a) healthy forests provide wood and hold soil in place; trees take in CO 2 and give off O 2 b) over half the world’s forests have been lost to deforestation c) leads to severe erosion, especially on mountain sides once erosion sets in it is harder for the forest to re-grow

26. B. Soil Use and Sustainability *it is possible to minimize soil erosion through careful management of both agriculture and forestry. 1. vulnerability – soil is most vulnerable to erosion when it is completely bare. 2. how to limit erosion : a) leave stems and roots in ground from previous crops

27. b) Crop rotation – planting different crops at different season and/ or times of the year.

28. c) Altering the shape of the land 1) contour plowing – plant fields across the slope rather than down the slopes, helps to prevent runoff. 2) terracing – shaping the land to produce level “steps.” *both help hold water and soil in place and prevent runoff

29. 3. Sustainable Forestry Options a) selective harvest of mature trees – promotes the growth of younger trees and thus preserves the forest and its soil. b) tree farms - protects soil and acts as a renewable resource.

30. II. Freshwater Resources *What do we rely on water for? -goods and services -drinking -industry -transportation -energy -waste disposal -irrigation

31. *freshwater is NOT unlimited ex) Ogallala aquifer – spans 8 states form South Dakota to Texas, took a million years to collect, but currently more is being pumped out than is being replenished. *expected to run dry in 20-40 years

32. *We must protect the ecosystems that collect and purify water. A. Water Pollution 1. Pollutant – harmful material that can enter the biosphere. 2. Examples of water pollutants a) point source pollution – comes from a single source. Ex) oil spill

33. Point source water pollution:

34. b) Nonpoint sources – come from multiple, smaller sources ex) grease and oil washed off streets chemicals released into air by factories and cars

35. 3. Pollutants may enter both surface water and underground water supplies. *The primary sources of water pollution are industrial and agricultural chemicals, residential sewage, and nonpoint sources. 4. Industrial and Agricultural Chemicals a) PCB’s (polychlorinated biphenyl) – organic compounds w/ 2-10 chlorine atoms attached to 2 benzene rings; used as dielectric and coolant fluids

36. *banned in 1979 by the United States Congress due to multiple large scale contamination events.

37. b) Heavy metals – cadmium, lead, mercury, zinc c) pesticides and insecticides – can enter the water supply from run off after heavy rains or can seep into groundwater. Ex) DDT

38. DDT – pesticide sprayed on crops; weakens the shells of birds’ eggs; banned in the 1970’s

40. d) Biological magnification – occurs if a pollutant such as PCB’s or DDT is picked up by an organism and is not broken down or eliminated by the body; the pollutant collects in body tissue and gets concentrated as it moves through the food chain.

41. 5. Residential Sewage – think toilets; not poisonous, but contain high amounts of nitrogen and phosphorous. a) dead zones – small amounts of sewage can be taken care of by healthy ecosystems, but large amounts can cause bacterial and algal blooms which decrease O 2

42. Algal blooms in the Baltic Sea: b) disease – raw sewage also contains microorganisms that can spread disease.

43. B. Water Quality and Sustainability 1. One key to sustainable water use is to protect the natural systems involved in the water cycle. a) protect wetlands – they filter water by absorbing excess nutrients and getting rid of pollutants. b) forests – helps purify water that seeps into the ground or runs off into lakes and rivers.

44. 2. Watershed – an area where ground water, streams, and rivers drain into the same place. Ex) large lake or river *must consider cleaning up pollution in all areas of the watershed

45. 3. IPM – “integrated pest management” a) uses biological controls such as predators and parasites to regulate pests instead of pesticides b) also involves using less poisonous sprays c) crop rotation 4. drip irrigation – delivers water drop by drop directly to the roots of plants that need it.

46. Drip Irrigation

47. III. Atmospheric Resources *What are the major forms of air pollution? 1. ozone – a form of oxygen found naturally in the upper atmosphere; it absorbs harmful UV radiation from the sun before it reaches the Earth’s surface.

48. 2. Greenhouse gases - CO 2, methane (CH 4 ), and H 2 O vapor regulate global temperature. 3. For most of Earth’s history the quality of the atmosphere has been maintained by biogeochemical cycles; if we disrupt these cycles we could devastate air quality. A. Air Pollution *poor air quality = increase in respiratory illness, issues with asthma, and an increase in skin diseases.

49. *common forms of air pollution : -smog -acid rain -greenhouse gases -particulates 1. smog – gray brown haze formed by chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.

50. a) Ozone is a product of smog b) Ozone high in the atmosphere is good, but ground level ozone is not c) ground ozone – threatens health, especially for those with respiratory conditions.

51. Ex) Summer Olympics in Beijing 2008

52. 2. Acid Rain – results from the chemical transformation of nitrogen and sulfur that come from human activities; they collect in the water vapor and fall as acid precipitation. a) acid rain kills plants; disrupts the pH of soil b) changes pH of bodies of water

53. c) Dissolves and releases mercury and other toxic elements from soil. 3. Greenhouse gases – excess gases that accumulate and increase global warming. a) Burning fossil fuels releases CO 2 into the atmosphere b) Agricultural practices from raising cattle to farming rice release CH 4

54. 4. Particulates – microscopic particles of ash and dust released by industrial processes and diesel engines; small particulates can pass through the nose and mouth and enter the lungs. B. Air Quality and Sustainability *improving air quality is difficult *one major switch was going from leaded to unleaded gas; the switch started in 1973 and by 1996 leaded gas was banned.

55. 6.3 Biodiversity I. The Value of Biodiversity *Biodiversity – the total of all the genetically based variation in all organisms in the biosphere. A. Types of Biodiversity *3 levels: -ecosystem -species -genetic

56. 1. Ecosystem diversity – refers to the variety of habitats, communities, and ecological processes in the biosphere. 2. Species diversity – the number of different species in the biosphere or in a particular area. a) 1.8 million - # of species identified thus far b) 30 million – # estimated to be discovered *most diversity exists among single-celled organisms

57. 3. Genetic diversity – can refer to the sum total of all different forms of genetic information carried by a particular species; or by all organisms on earth. - total of all different genes present in that species

58. B. Valuing Biodiversity *Biodiversity is one of Earth’s greatest natural resources *Biodiversity’s benefits to society: 1) contributions to medicine 2) agriculture 3) provision od ecosystems goods and services

59. 1. Biodiversity and Medicine a) Wild species are the source of many medicines such as painkillers (aspirin) and antibiotics. b) Wild plants offer treatments for depression and cancer, such as taxol from the yew tree.

60. c) Foxglove – treats heart disease 2. Biodiversity and Agriculture a) domestic plants have “wild relatives” b) wild plants may offer new genes for: 1) breeding 2) genetic engineering for pest resistance

61. 3. Biodiversity and Ecosystem Services a) the number and variety of species in an ecosystem can influence the ecosystems: 1) stability 2) productivity 3) value to humans b) healthy and diverse ecosystems play a role in maintaining soil, water, and air quality c) missing a keystone species can have disastrous effects on the ecosytem; ex) sea otter, kelp, and urchins

62. II. Threats to Biodiversity 1. It is estimated that 99% of species that once lived are extinct; extinction is not new, but humans are exacerbating species loss. 2. Species diversity = genetic diversity; the more genetically diverse a species is, the greater it’s chance of survival. Thus if we wipe out a species we wipe out genetic diversity

63. 3. Humans reduce biodiversity by: a) altering habitats b) hunting c) introducing invasive species d) pollution e) causing climate change A. Altered Habitats 1. Habitat fragmentation – occurs when habitats are broken into pieces or “biological islands.”

64. 2. The smaller the habitat the fewer the # of species that can live there and the smaller their population becomes. B. Hunting and the demand for wildlife products 1. Humans can push species to extinction by hunting. Ex) 1800’s hunting wiped out the Carolina parakeet and passenger pigeon.

65. 2. Animals are sometimes hunted for their hides, or skins, or sometimes to be kept as pets. 3. CITES – The Convention on International Trade in Endangered Species  bans international trade in products that come from a list of endangered species.

66. *unfortunately it is difficult to enforce laws in remote wilderness areas. C. Introduced Species 1. introduced species – organisms that are introduced to new habitats. 2. Introduced species can become invasive and threaten biodiversity. Ex) think of the gypsy months or European rabbits

67. D. Pollution 1. Pollutants threaten biodiversity ex) DDT and bird eggs such as the brown pelican and peregrine falcon.

68. 2. Acid rain from pollution stresses land and water organisms. E. Climate Change *major threat to biodiversity 1. tolerance – organisms have a natural range of tolerance in their area, if the climate changes so that they are no longer in their range they may suffer. 2. Species in fragmented habitats are more at risk b/c they may not be able to get to a new suitable habitat.

69. III. Conserving Biodiversity *To conserve biodiversity we must protect individual species, preserve habitats and ecosystem, and make certain that human neighbors of protected areas benefit from participating in conservation efforts. A. Protecting Individual Species 1. AZA – Association of Zoos and Aquariums – oversees species survival plans (or SSP’s); designed to protect threatened and endangered species. Ex) captive breeding

70. 2. Captive Breeding – involves careful selection and mating of animals to ensure maximum genetic diversity. 3. Ultimate goal of SSP’s – reintroduction of individuals back into the wild; ex) giant panda

71. B. Preserving Habitats and Ecosystems 1. The main goal of conservation efforts is to protect entire ecosystems. 2. reserves and national parks – to protect ecosystems conservationists and governments set up some land as national parks and reserves to protect these ecosystems

72. 3. Ecological hot spots – a place where a significant number of species and habitats are in immediate danger of extinction  these areas are key target areas for protection.

73. C. Considering Local Interest 1. Protecting biodiversity often demands that individuals change their habits or the way they earn their living. 2. incentives – US government has offered tax credits to individuals who bought hybrid cars or install solar panels. 3. ecotourism – some countries have developed national parks to attract tourists and make money to preserve these areas.

76. 4. Carbon credits – companies can release a certain amount of carbon into the environment; any unused carbon may be sold back or traded. Section 6.4 : Meeting Ecological Challenges I. Ecological Footprints 1. ecological footprint – describes the total area of functioning land and water ecosystems needed to both provide the resources an individual or populations use to absorb and make harmless the wastes that an individual or population generates.

78. 2. Footprints take into account the need to provide resources such as energy, food, water, and shelter, and to absorb such wastes as sewage and greenhouse gases.

79. 3. Footprint calculations are used to estimate the biosphere’s carrying capacity for humans. A. Footprint Limitations 1. Calculating footprints is complicated 2. Footprints only give a “snapshot” of the situation at a particular point in time. B. Comparing Footprints 1. although calculating “absolute” footprints is difficult, ecological footprints can be useful for making comparsons among different populations.

80. 2. According to one data set, the average American has an ecological footprint over 4x larger than the global average. 3. Per person use in America is about 2x that in England and Japan, and 6x that in China. 4. Ecological Footprint (per country) = footprint for a typical citizen X size of the population

81. II. Ecology in Action *the future of the biosphere depends on our: 1) ecological footprints 2) global population growth 3) technological development *how to achieve a sustainable future: 1) recognize a problem in the environment 2) research the problem to determine the cause 3) use scientific understanding to change our behavior

82. Case Studies!!!!!!!!!