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Humans in the Biosphere

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Presentation on theme: "Humans in the Biosphere"— Presentation transcript:

1 Humans in the Biosphere
Chapter 6

2 Changing Landscape Activities affect environment
Relationship between resources and sustainable use

3 Effect of Human Activity
Living on Island Earth We affect environment when: Obtain food Eliminate waste products Build places to live Humans impact regional and global environments: Agriculture Development Industry Which impact natural resources such as soil, water and the atmosphere.

4 Effect of Human Activity
Agriculture Dependable supply of food that can be stored for future use Monoculture-clearing large areas of land to plant a single highly productive crop annually (soybean) Efficient sowing , tending, and harvesting of crops Providing food for nearly 7 billion people-impacts natural resources Fertilizer production and Farm machinery-consume large amounts of fossil fuels.

5 e.g.-Canola Oil Soybean

6 Effects of Human Activity
Development Dense human communities produce lots of wastes. Not disposed correctly they affect air, water and soil. Consumes farmland Habitat fragmentation

7 Effects of Human Activity
Industrial Growth Conveniences utilize a great deal of energy to produce and power Energy comes from burning fossil fuels such as coal, oil and natural gas (emits greenhouse gases-90 % of US emissions) Past-dumped waste directly into air, water and soil

8 Sustainable development
Goods-things that can be bought and sold and have value in terms of dollars and cents. Services-processes or actions that produce goods. Ecologically-these are goods and services produced by ecosystems that benefit the human economy.

9 What type of goods and service?

10 Ecosystem Goods and Services
Many natural and free of charge Breathable air Drinkable water In environment cant provide-society must spend money to produce E.g. many places drinkable water is free; source polluted or damages and water quality falls-must pay for water treatment to be safe.


12 Renewable and Nonrenewable Resources
Can be produced or replaced by healthy ecosystem. E.g. southern white pine that can grow back when an old tree dies or is cut down. Natural processes cannot replenish these goods within a reasonable amount of time. E.g. fossil fuels (formed from buried organic material over millions of years) ; when depleted they are gone.


14 Sustainable Resource Use
Conscious Way to use resources Provides for human needs while preserving the ecosystem that produce natural resources No harm to soil, water or climate Flexible enough to survive environmental stresses (droughts, floods, heat waves, etc.) Human economic systems-more than just enable people to survive-must help situation.


16 Using Resources Wisely

17 Soil Resources Important objects that rely on soil
Grain in cereal Wood in home Pages of textbook Healthly soil supports agriculture and forestry.

18 Topsoil- mineral- and nutrient- rich portions of soil
GOOD absorbs and retains moisture allows draining rich organic matter and nutrients Renewable Resource Properly managed Healthy soil can take centuries to forms but be lost quickely

19 1930s drought Badly eroded once-fertile soil of Great Plains
Thousands lost jobs and homes Became a desert w/ dry soil- aka “dust bowl” Cause-conversion of prairie land to cropland in way that left soil vulnerable to erosion (wearing away).

20 Soil Erosion Removal of soil by water or wind
Worse- land plowed and left barren b/w plantings. No roots to hold soil-easily washed away Badly eroded-organic materials and minerals that make soil fertile are carried away.

21 Desertification Dry climates-farming, overgrazing, seasonal drought and climate change can turn farmland to desert. Great Plains is an example 40% of Earth’s land is considered at risk

22 Desertification Risk

23 Deforestation Loss of forest Forests value Wood Hold soil in place
Protect quality of water Absorb CO2 Moderate local temperature

24 Deforestation ½ of world’s old-growth forests (never been cut) lost
Temperate areas-forest can regrow after cutting; centuries for succession Tropics-forest DO NOT grow back after logging Old-Growth forest usually considered non-renewable.

25 Deforestation can: Leads to severe erosion
Change local soils and microclimates in a way prevent regrowth of trees E.g Tropical Rain Forest- Soil is thin and decomposition quick b/c of high heat and humidity. Soil ok for few years Then becomes wasteland; harsh conditions prevent regrowth

26 Soil use and sustainability
Minimize erosion through careful management of both agricultural and forestry Leaving stems and roots can help Crop rotation-planting different crops at different seasons or in different years (erosion and nutrient loss) Altering shape (e.g. planting fields across, instead of down and slope; reduce water runoff and erosion.

27 Freshwater Resources Goods and services-drinking water, industry, transportation, energy and waste disposal. Fresh water is renewable resource; some is not Ogallala Aquifer- spans 8 states (South Dakota to Texas); more than a million years to collect; not replenished by rainfall; expected to run dry in years. 3% Earth’s water is fresh water- most locked in ice at poles

28 Water Pollution Pollutant-harmful material that can enter biosphere.
Point source- pollution enter water supply from single source (e.g. factory or oil spill) Nonpoint source- pollutant enters from many smaller sources (e.g. grease and oil washed off streets; chemicals released by factories and autos) Primary sources-industrial and agriculture chemicals; residential sewage; and nonpoint sources

29 Industrial and Agricultural Chemicals
Industrial Chemicals Agricultural Chemicals PCBs-Chemical used in industry until 1970s; large-scale contamination events; banned. Can be difficult, if not impossible to eliminate Others-Cadmium, lead, mercury and zinc Pesticides and insecticides Runoff-enter water supply DDT-pesticide; dangerous, controls against pest and disease carrying mosquitoes; threatened fish-eating birds-females laid fragile eggs; lowered numbers Biomagnification

30 Biological Magnification
Pollutant concentrations increase as they move up the trophic levels.

31 DDT (dichlorodiphenyltrichloroethane)

32 Residential Sewage Household waste-becomes sewage
Not poisonous-contains lots of nitrogen and phosphorus Reasonable amounts-process and absorbed healthy ecosystem Large amounts-blooms of algae and bacteria rob water of oxygen. Dead zones-oxygen poor areas- fresh or salt water Sewage carry microorganism that can spread disease.

33 Water Quality and Sustainability
Protect natural systems involved in water cycle. Watershed-land whose groundwater, streams, and rivers drain into same place (lake or river) Sewage treatment can lower bacteria and prevent dead zones Integrated Pest Management (IPM) instead of pesticides-biological control

34 Water Quality and Sustainability
Use of less-poisonous sprays Crop rotation Water conservation drip irrigation

35 Atmospheric Resources
Common resource whose quality has a direct effect on health *Provides Oxygen we breathe

36 Ozone Form of oxygen-O3 Natural; Upper atmosphere
Absorbs harmful UV radiation from sunlight; protecting skin from cancer

37 Atmospheric Services Greenhouse Gases- (CO2, Methane and water vapor) regulate global temperatures W/out Earth would be 30°C cooler Never “Used Up” Human activities can have lasting impact

38 Air Pollution Air quality reduced-respiratory illnesses are made worse and tend to increase. Globally-climate patterns may be impacted

39 Cause of Air Pollution Industrial processes Burning fossil fuels

40 Forms of Air Pollution Smog Acid Rain Greenhouse Gases Particulates

41 Smog Gray-brown haze formed by chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.

42 Smog Products Ozone-High in atmosphere protective; ground level, threatens health, especially those with respiratory conditions. 2008 summer Olympics in Beijing

43 Acid Rain Rain containing nitric and sulfuric acids
Cause-burning fossil fuel releases nitrogen and sulfur compounds; combine with water vapors and from acids. Effects kills plants Damages leaves Changes chemistry of the soil and surface water Dissolve and release mercury and other toxic elements from soil (enter other parts of biosphere)


45 Greenhouse Gases Burning fossil fuels and forest-release carbon into atmosphere as CO2 Agriculture-raising cattle to farming rice releases methane and other green house gasses. Contribute to global warming and climate change.

46 Particulates Visible, microscopic particles from certain industrial processes and certain diesel engines. Ash, dust, soot, smoke aerosols Enter nose and mouth-to lungs and cause serious health problems.

47 Air Quality and Sustainability
Difficult to improve Doesn’t stay in one place Doesn’t “belong” to anyone Improvements Automobile emissions standards Clean-air regulations Phasing out of lead gas; now banned in US

48 Complete: Analyzing Data, page 164.

49 Biodiversity Total of all the genetically based variation in all organisms in the biosphere Variety of organisms

50 Types of Biodiversity Ecosystem Diversity-Variety of habitats, communities and ecological processes in the biosphere. Species Diversity- The number of different species in the biosphere or in a particular area. 1.8 species identified and named 30 million more to be discovered Genetic Diversity-Sum total of all different forms of genetic information carried by a particular species, or all organisms on Earth.

51 Valuing Biodiversity Greatest natural resources
Contributions to medicine and agriculture Provision of ecosystem goods and services Make our world a beautiful, interesting place

52 Biodiversity and Medicine
Willow bark Wild species are original sources of many medicines Painkillers-aspirin Antibiotics-penicillin Blue green mold Chemicals in wild treat diseases like depression and cancer Foxglove-Digoxin for heart disease

53 Biodiversity and Agriculture
Wild plants may carry genes we can use for: Plant breeding Genetic engineering- transfer disease or pest resistance or other useful traits to plant crops.

54 Biodiversity and Ecosystem Services
Number and variety in ecosystem can influence stability, productivity and value to humans. Keystone species can completely change an ecosystem Healthy and diversity ecosystems play a role in maintaining soil, water and air quality

55 Species Loss Scientist estimate 99% of species that have lived are extinct Species loss is now approaching 1000 x’s the “typical” rate. Human knowledge held in genes is lost

56 Species diversity/Genetic Diversity
More genetically diverse, greater chances of survival Human activity reduces genetic diversity; species greater risk of extinction Ecosystems damages-organisms more at risk

57 Humans reduce biodiversity
Altering habitats Hunting Introducing invasive species Releasing pollution into food webs Contribute to climate change


59 Altered Habitats Agriculture and urban development-loss of habitats; some species become extinct Habitat fragmentation-development splits ecosystems into pieces leaving “islands” Smaller island, fewer species More vulnerable- Open to attack or damage

60 Hunting and Demand for Wildlife Products
Hunting can lead to extinction Carolina parakeet Passenger pigeon Today endangered species protected; but not in Africa, South American and Southeast Asia Hunting purposes Birds hunted for meat Hides and skins for commercial value Body parts of medicinal properties Pets Habitat fragmentation leaves less hiding spaces for prey

61 CITES Convention on international Trade in Endangered Species
Bans international trade in products from a list of endangered species.

62 Introduced/Invasive Species
Threaten biodiversity Change ecosystems Drive native species close to extinction Economical loss E.g. Leafy spurge; infest millions of hectares across Northern Great Plans; displaces grasses and other plants; milky latex can sicken/kill cattle and horses; ranchers and farmers losses exceeded $120 million.

63 Pollution DDT-prevents birds from laying healthy eggs
Peregrine Falcon #’s plummeted from use of chemicals Acid Rain-stress on land and water organisms Increase CO2- dissolved in oceans making more acidic, threatens environment

64 Climate Change Organisms have specific tolerance ranges to abiotic factors; changes beyond tolerance can be devastating; must be moved or face extinction Estimates vary regarding effects of climate change on biodiversity. 1.5 °C to 2.5 °C over late 20th century-30% species are likely to face risk of extinction. Above 3.5°C risk is 40-70%

65 Conserving Biodiversity
Protect individual species Preserve habitats and ecosystems Human neighbors of protected areas benefit from conversation efforts.

66 Protecting Individual Species
Association of Zoos and Aquariums (AZA) oversees species survival plans (SSPs) that are designed to protect threatened and endangered species. Captive breeding programs-breed in controlled place Reintroduction programs- back into habitat Currently 180 species are covered by SSPs.

67 Preserving Habitats and Ecosystems
Not just species, but the habitat Parks and Reservation-conservation efforts Marine Sanctuaries-coral reefs and marine mammals Protect area large enough to protect biodiversity

68 Ecological Hot Spots Place where significant numbers of species and habitats are in immediate danger of extinction 1500 species of native vascular plants Lost at least 70% of original habitat 34 hot spots cover 2.3 of Earth’s land surface/ 50 % of plant species & 42% of terrestrial vertebrates

69 Local Interest Individuals must change habits or way earn living-incentive to those involved Tax credits- e.g. for solar panels; Energy Star; hybrid cars Parks and preserves- attract tourist dollars Australia-farmers paid to plant trees; improved water quality and improved cow’s health; shade in the summer

70 Carbon Credits Incentives to Industry to cut fossil fuels Encourages
Certain amount permitted to be burned Rest sold back at market value or traded to other company Encourages Industries to pay for lower emissions machinery Adopt carbon saving practices Less financial burden


72 Ecological Footprint Ecological Footprints describes the total area of functioning land and water ecosystems needed both to provide and the resources an individual or population uses and to absorb and make harmless the wastes that an individual or populations generate.

73 Ecological Footprints considerations
Energy Food you eat Miles you travel Electric use Shelter Waste and Sewage Green house gases

74 Footprint limitations
No way to calculate exact numbers No universal way to calculate footprint size Only a “snapshot” of situation at particular time

75 Comparing Footprints Useful in making comparison among different populations One data set-America has an ecological footprint over 4 x larger thane the global average Per person use of resources in US 2x that in England 2x that in Japan 6x that in China Calculate Footprint for Country- footprint for typical citizen and then multiply by size of population

76 Ecology in Action Future depends on:
Ecological footprints Global population growth Technological development Ecological principles for sustainable future Recognizing the problem in environment Researching the problem to determine its cause Use scientific understanding to change behavior

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