Response to change

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  • 1. response to change
    What happens to an ecosystem when it is disturbed?
  • 2. Ecosystem Changes
    Ecological change is referred to as Succession
    the regular pattern of changes over time in the types of species in a community
    Interactions among living things results in these changes
    First organisms to arrive, usually small plants, are called pioneers
    The end result of these changes, if left undisturbed, is the climax community
  • 3. What types of animals would you expect to inhabit each stage?
  • 4. Animals in succession
    As succession occurs, the animals correspond to the plants that are present
    Small animals (insects, things that live in soil, small rodents) that eat the pioneer species appear first
    Then larger animals that eat the smaller animals and/or the next plant species appear
    This continues until you have the climax group of animals as well as plants
  • 5. Types of Succession
    Two types depending on how it starts:
    Primary Succession – new land is created and succession begins
    Takes much longer (no soil!)
    Example: volcanic eruption creates land; bare rock exposed from melted glacier
    weathering plays a major role in creating soil
  • 6. Photo credit: © Joel E. Harvey
    After Mount St. Helens erupted on May 18, 1980, the story most people heard was about violence and devastation. One of the greatest natural disasters of our time, the eruption killed 57 people, sheared 1,300 feet off the summit of the mountain, and turned a pristine forested landscape into a barren, lifeless wasteland.
  • 7. Photos taken by Mrs. McCurdy 1998
    Its eruption in 1980 destroyed large areas of forest. In 1988 J. Alean documented the starting re-colonization of the terrain by plants, and in 2001 the photos were repeated.
    Photos taken by Ms. McClure 2006
  • 8. Types of Succession
    Secondary Succession – changes occur on land where an existing ecosystem has been destroyed
    Happens faster
    Examples: Forest Fire, abandoned farm fields, land left alone for many years
  • 9. Succession in aquatic ecosystems
    called eutrophication
    the gradual change of an aquatic ecosystem into a terrestrial (land) ecosystem
    as organisms die in the aquatic ecosystem, they fall to the bottom and gradually fill in the pond/lake/river basin
    different species of plants (like cattails or cottonwood trees) will start to grow on the edges, continuing the process
  • 10. Eutrophication
    humans GREATLY speed up this process by polluting the water ways with nitrogen and phosphorus
    found in many common products like fertilizer, laundry detergent
    these elements cause increased plant growth and more rapid animal death
    also speeds up with increased temperatures
  • 11.
  • 12. Three Categories of Human-Induced Environmental Problems
    #1 Resource Depletion
    Natural resources become depleted when a large part of it has been used up. Natural Resources can be either:
    Renewable - they are constantly being replaced
    trees, water, crops, sun
    Nonrenewable - they cannot be replaced (or replenish too slowly)
    animal and plant species, fossil fuels, minerals
  • 13. Results of Resource Depletion
    Deforestation: cutting large areas of trees for use in building products, fuel, etc. or to use the land for other purposes.
    Desertification: destructive use of land results in the formation of desert conditions
    Sustainable use can prevent both of these
  • 14. Human-induced environmental problems
    #2 Pollution
    Pollution is the introduction of harmful levels of chemicals or waste material into the environment
    Pollution may be harmful to human health
    Pollution can occur in air, soil, or water
    Pollution can take the form of liquid, solid, gas, or even energy
  • 15. Results of Pollution
    Acid Precipitation – rain/snow/ice that has a pH less than 7.
    Results from sulfur oxides and nitrogen oxides in the atmosphere mixing with the water in the atmosphere to form sulfuric and nitric acid.
    Dangerous to living things – pH in environment may become intolerable
    Destructive to environment – acid dissolves certain types of stone
  • 16.
  • 17. Results of pollution
    Biomagnification – process by which a chemical moves through the food chain, becoming more concentrated.
    May be harmful/lethal to organisms at the top of the food chain, reducing biodiversity.
    • Biomagnification video - MUST SEE
  • Human-induced environmental problems
    #3 Extinction
    Extinction means the last individual of a species has died and the species is gone forever
    Thousands of species are becoming extinct each year
    Endangered species are those whose extinction is very close, and will happen without some sort of intervention
  • 18.
  • 19. A sustainable world
    In a sustainable world, human populations can continue to exist with a high standard of living and health because
    Biodiversity is preserved
    Habitats are preserved
    Nonrenewable resource are used sparingly and efficiently
    Renewable resources are used no faster than they can be replaced
    There are enough resources for the next generation
  • 20. Biodiversity is preserved
    Biodiversity – all of the different forms of life
    All living things are connected, and therefore depend upon each other for survival.
    Three Levels:
    Species diversity – all of the different species in an area
    Genetic diversity – all of the different genetic combinations in a particular species
    Ecosystem diversity – all of the different biological, geological, chemical factors in an area
  • 21. Habitats are preserved
    Destruction of appropriate habitat can lead to extinction
    Habitat fragmentation – some living things require large areas of land. Habitat can be come “fragmented” when human development separates areas.
    Invasive species– occurs when a species is introduced to a habitat in which it is not naturally found.
    If there is no predator for that species, it may increase in number at the expense of native species, who will now have to compete for resources
  • 22. Invasive species
  • 23. Global Changes occur when ecosystem is disrupted over long periods of time
    Ozone Depletion – reduction in the thickness of the ozone layer
    Ozone (O3) – located in the stratosphere, filters UVB light before it reaches the earth
    Ozone is broken down into oxygen gas (O2) by CFC’s (chlorofluorocarbons)
    Why does this matter?
    UVB has been linked to skin cancer, cataracts, damage to materials like plastics, and harm to certain crops and marine organisms. Reduction in ozone means an increase in UVB!
  • 24. Ozone “hole” September 2009
  • 25. Global Changes (Continued)
    2. Global Warming: increase in the average temperature of the Earth
    Dependent on the greenhouse effect – the Earth is warmed because the gases in the atmosphere trap heat
    Greenhouse gases:
    Carbon dioxide
    Methane
    Surface Ozone
    CFC’s
    Nitrous oxides
  • 26. Temperature and Carbon Dioxide
    In historical data, temperature and carbon dioxide levels have been closely connected
  • 27. Greenhouse Effect
  • 28. Results of Increased Global Temperatures
    Sea level rise
    Loss of habitable land
    Coral bleaching
    Shoreline erosion
    Changes in agriculture
    May be positive or negative
    Appropriate growing climate may shift
    Changes in water resources
    Areas of drought/flooding as weather patterns change
  • 29. IF nonrenewable resource are used sparingly and efficientlyAND renewable resources are used no faster than they can be replaced
  • 30. There will be enough resources for the next generation
    Sustainable Use of Natural Resources:
    More efficient technology to produce electricity
    Increase use of alternative energy sources
    Increase fuel efficiency in automobiles
    Conservation: the act of reducing the amount of resources one consumes.
    3 R’s – reduce, reuse, recycle