The study of the interactions between organisms and the living and nonliving components of their environment. - PowerPoint PPT Presentation

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The study of the interactions between organisms and the living and nonliving components of their environment.

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Title: The study of the interactions between organisms and the living and nonliving components of their environment.


1
Ecology
  • The study of the interactions between organisms
    and the living and nonliving components of their
    environment.

2
Table of Contents Ecology
  • Levels of Organization slides 3-7
  • Organism Ecology (vocabulary) slides 8-9
  • Ecosystems and Energy slides 10-17
  • Ecosystem Recycling slides 18-20
  • Populations slides 21-30
  • Succession slides 31-36
  • Invasive Species slides 37-41
  • Modern Issues slides 42-57

3
Levels of Organization
  • Biosphere
  • The thin layer of the earth that supports life
    (as thin as the skin of an apple!)

4
Levels of Organization
  • Biomes
  • Any of the worlds major ecosystems, classified by
    predominant vegetation and characterized by
    adaptations of organisms to that particular
    environment.
  • Terrestrial Biomes include
  • Tropical forests, Savanna, Desert, Chaparral,
    Temperate Grassland, Temperate Broadleaf Forest,
    Coniferous Forest, Tundra, High Mountains, Polar
    Ice
  • Aquatic Biomes include
  • Lakes, Wetlands, Streams and Rivers, Estuaries,
    intertidal zones, oceanic pelagic zones, coral
    reefs, marine benthic zones

5
Levels of Organization
  • Ecosystem
  • Includes all of the living (biotic) and non
    living (abiotic) components within a particular
    place.
  • Biotic Components of a Pond
  • includes fish, turtles, plants, algae, insects,
    bacteria.
  • These interact with each other.
  • Abiotic Components of a Pond
  • water temperature, dissolved oxygen and carbon
    dioxide, nitrogen levels, sun light, pH level.
  • These are necessary for the living organisms to
    survive.

6
Levels of Organization
  • Community
  • Includes all of the interacting organisms within
    an area.
  • Population
  • Includes all of the members of a species that
    live in one place at a time.
  • Organism
  • The individual in a population.
  • Represents the simplest level of organization.
  • Most studies focus on the individual organism and
    how it has adapted to overcome the challenges in
    its environment.

7
Levels of Organization
8
Organism Ecology
  • Biotic Factors - living factors that affect an
    organism.
  • Abiotic Factors - non living factors that affect
    an organism.
  • Habitat - where an organism lives
  • Environmental Fluctuations
  • As the environment changes, an organism must be
    able to tolerate those changes otherwise it will
    stress and exhibit reduced performance or simply
    die.

9
Organism Ecology
  • Niche
  • Way of life or the role of an organism in its
    environment.
  • Bacteria recycle nutrients
  • Predators keep prey populations under control
  • Plants use CO2 and produce O2 also provide food
    for grazers.

10
Ecosystems and Energy
  • Whats the 10 Rule?

11
Energy Transfer
  • A common characteristic of all living organisms
    is they require energy to carry out metabolic
    activities.
  • Producers
  • Usually photosynthetic plants (autotrophs)
  • Can also be chemosynthetic (certain bacteria)

12
Energy Transfer
  • Measuring Productivity
  • Gross Primary Productivity
  • Rate at which producers capture energy
  • Energy is used to make sugar which is used for
    repairs, for growth or cellular respiration
  • Biomass
  • Organic matter in the ecosystem
  • Net Primary Productivity
  • Rate at which biomass accumulates in an ecosystem
  • NPP is highest in biomes like tropical rain
    forests and estuaries

13
Energy Transfer
  • Consumers are Heterotrophs
  • Herbivores - consume producers
  • Cows, deer, mice
  • Carnivores - eat consumers
  • Mountain Lions, bald eagles, snakes
  • Omnivores - eat both producers and consumers
  • Bears, people
  • Detritivores - feed on dead matter
  • Vultures, certain beetles
  • Decomposers - decay complex molecules of dead
    tissue and wastes into simpler molecules
  • Bacteria, Fungus

14
Energy Transfer
  • Energy Flow
  • Energy in an ecosystem moves from one organism
    into another
  • Trophic Level
  • The organisms position in the sequence of energy
    transfers
  • Food Chain
  • A single pathway of feeding relationships in an
    ecosystem that shows energy transfer
  • Food Web
  • a series of interrelated food chains in an
    ecosystem

15
Food Chain
16
Food Web
17
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18
Ecosystem Recycling
  • The Water Cycle

19
Ecosystem Recycling
  • The Carbon Cycle

20
Ecosystem Recycling
21
Ecology
  • Populations
  • Growth, Carrying Capacity, Variables

22
Population Growth
  • If resources, such as food, water and habitats,
    were unlimited, then a population of organisms
    would grow in an exponential fashion.
  • Imagine if this growth curve represented
    mosquitoes, elephants or people. The earth would
    be over-run and all resources would be rapidly
    depleted!

23
Population Growth
  • Fortunately, in nature resources are limited.
  • Limited resources slow growth and if you graph
    numbers of organisms over time, the graph takes
    the shape below.

24
Population Carrying Capacity
  • Notice the top of the smooth graph is labeled
    carrying capacity.
  • This is the number of organisms that a habitat
    can sustain with the available resources.
  • If the number of organisms exceeds the carrying
    capacity, the population can begin to decline.

25
Population Curve
  • Notice the tail on this graph.
  • When resources have been overused or depleted,
    the organisms begin to die out.

26
Population Carrying Capacity
  • What happened to the reindeer on Matthew Island?
  • The reindeer overused their resources and
    exceeded the islands carrying capacity almost
    dying out.

27
Population Size Variables
  • What other factors affect the size of a
    population?
  • Birth Rates
  • Death Rates
  • Immigration-the movement of individuals from
    other areas.
  • Emigration-the movement of individuals out of a
    population.

28
Population Size Variables
  • If the arrows represent actual rates, what would
    happen to the size of the population circle if
    the death rate arrow was cut in half or the
    immigration arrow was doubled?

29
Population Size Variables
  • If the death rate arrow were cut in half or the
    immigration arrow was doubled, the population
    circle would increase in size.

Population
Death Rate
Birth Rate
Emigration
Immigration
30
Population Variables
  • In the United States, birth rates, death rates
    and emigration rate are low but our immigration
    rate is climbing. How is that affecting our
    population size?

31
Ecology
  • Succession

32
Ecological Succession
  • Changes in the number and type of organisms in a
    community are most apparent after some type of
    disturbance to the habitat.
  • The disturbed area may be colonized by a variety
    of new organisms, which are gradually replaced by
    other organisms until a stable group of species
    persists within the area.
  • This process is called Ecological Succession.

33
Ecological Succession cont.
  • One type of ecological succession is called
    Primary Succession.
  • In primary succession, a new piece of new real
    estate, such as a volcanic island where soil and
    organisms are lacking, is invaded by lichens and
    mosses which are usually blown in as spores.
  • As soil develops, these organisms are overgrown
    by grasses, shrubs and trees that are blown in or
    brought in by animals.
  • Eventually, the area is colonized by plants that
    become the main form of vegetation.
  • This process can take hundreds to thousands of
    years.

34
To the right, the foreground is bare rock covered
with lichens and mosses. The middle ground
contains a small amount of soil with plants. The
background is a stable forest.
Below is an example of rock covered with lichens.
35
Ecological Succession
  • Secondary succession occurs when an existing
    community is cleared by some disturbance such as
    fires, glaciation, deforestation, etc.
  • Under these circumstances the sequence of
    colonization can vary but generally weeds and
    other opportunistic plants first invade followed
    by grasses or shrubs. These can then be replaced
    by trees species.

36
Secondary succession occurs in areas where plants
were already established but were disturbed. This
sequence represents a once planted field in North
Carolina.
37
Ecology
  • Invasive Species
  • (Non-Native)

38
Invasive Species
  • After habitat loss and degradation, mostly due to
    human activity, the biggest cause of early
    organism extinction is the introduction of
    harmful invasive species into an ecosystem.
  • Invasive species have been intentionally and
    accidentally introduced in the U.S. for years.
  • Intentionally introduced species include
  • wheat, rice, corn, cattle, poultry.
  • Accidentally introduced species include an
    estimated 7100 organisms in the U.S. alone

39
Invasive Species cont.
  • Accidentally introduced species include
  • Brown tree snakes, Japanese beetles, African
    honeybees, zebra mussels, Formosan Termites,
    Burmese pythons, Gypsy moths, etc.
  • Species like these cost the U.S. public
    approximately 261,000 per minute in damage and
    control.

40
Invasive Species
  • These invasive species cause so much damage
    because they have no natural predators,
    competitors, parasites or pathogens when
    introduced into a new environment.
  • Nonnative species can reduce or wipe-out
    populations of many native species, trigger
    ecological disruption, cause human health
    problems and lead to economic loss.

41
Invasive Species
Kudzu Vine
Burmese Python
Formosan Termite
Gypsy Moth Catepillar
42
Ecology
  • Modern Issues
  • (Optional Information)

43
Ecology
  • Human Population Explosion
  • From 2 Billion in 1930 to 6 Billion in 1996
  • Projected to reach over 7.8 Billion in 2050

44
World Population Projections
45
Ecology
  • Mass Extinctions
  • The last extinction occurred 65 mya probably due
    to an asteroid impact.
  • Currently organisms are going extinct at a rate
    unseen since the dinosaurs last died out.
  • By 2100, it is expected that one fifth of the
    current organisms will be extinct.
  • Why? Habitat destruction, over hunting, the
    introduction of predators and disease.

46
Mass Extinction 1
  • The following mass extinctions were due to
    natural causes.
  • First major extinction (c. 440 mya) Climate
    change (relatively severe and sudden global
    cooling) seems to have been at work at the first
    of these-the end-Ordovician mass extinction that
    caused such pronounced change in marine life
    (little or no life existed on land at that time).
    25 of families lost (a family may consist of a
    few to thousands of species).

47
Mass Extinctions 2-3
  • Second major extinction (c. 370 mya) The next
    such event, near the end of the Devonian Period,
    may or may not have been the result of global
    climate change. 19 of families lost.
  • Third major Extinction (c. 245 mya) Scenarios
    explaining what happened at the greatest mass
    extinction event of them all (so far, at least!)
    at the end of the Permian Period have been
    complex amalgams of climate change perhaps rooted
    in plate tectonics movements. Very recently,
    however, evidence suggests that a bolide impact
    similar to the end-Cretaceous event may have been
    the cause. 54 of families lost.

48
Mass Extinction 4
  • Fourth major extinction (c. 210 mya) The event
    at the end of the Triassic Period, shortly after
    dinosaurs and mammals had first evolved, also
    remains difficult to pin down in terms of precise
    causes. 23 of families lost.

49
Mass Extinction 5
  • Fifth major extinction (c. 65 mya)
  • Most famous, perhaps, was the most recent of
    these events at the end-Cretaceous. It wiped out
    the remaining terrestrial dinosaurs and marine
    ammonites, as well as many other species across
    the phylogenetic spectrum, in all habitats
    sampled from the fossil record. Consensus has
    emerged in the past decade that this event was
    caused by one (possibly multiple) collisions
    between Earth and an extraterrestrial bolide
    (probably a comet). 17 of families lost.

50
Last Extinction Event
51
The Sixth Mass Extinction
  • How is the Sixth Extinction different from
    previous events?
  • The current mass extinction is anthropogenic
    (caused by humans).
  • Humans are the direct cause of ecosystem stress
    and species destruction in the modern world
    through such activities as
  • Habitat degradation
  • Overexploitation of species
  • Pollution
  • The introduction of invasive species

52
Ecology
  • Thinning Ozone Layer
  • This layer is responsible for protecting life
    from UV radiation from the sun.
  • CFCs in the earths upper atmosphere cause ozone
    (O3) to break down into oxygen (O2).
  • This effect is magnified at the earths poles.
  • A 1992 treaty banned CFCs (Chloroflourocarbons)
    from use, but long-term persistence of CFCs in
    the atmosphere continues to degrade ozone.
  • Recent evidence suggests ozone degradation is
    slowing.

53
Total Ozone
54
Ozone Hole
55
Ecology
  • Modern Issues
  • Global Warming
  • Carbon Dioxide (CO2) produce by humans has
    increase the atmospheric CO2 steadily since the
    late 1800s.

56
Ecology
  • Global Warming
  • The increase in greenhouse gases (CO2, O3, CH4)
    is slowly increasing the average temperature of
    the earth.
  • This is resulting in rising sea level, melting
    ice caps, changes in storm patterns and changes
    in oceanic current flows.
  • Environmental knowledge is essential in trying to
    stop and reverse destructive human practices.

57
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