Chapter 18 Introduction to Ecology

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Chapter 18Introduction to Ecology
Biology I Mrs.
Schalles
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ECOLOGY?

• - comes from the GREEK Words OIKOS (HOUSE where
  one lives) LOGOS (STUDY)
• Ecology is the Study of the House in which We
  Live.

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Ecology can be defined more specifically as

• The Study of the Interactions between
• Living Organisms
• Non-living Components of their Environment.

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Parts of the Environment

• Biotic- Living Organisms
• -Producers, Consumers, and Decomposer
• Abiotic- Non-living components -sunlight,
  temperature, humidity, water supply, soil type,
  mineral nutrients (Nitrogen, Phosphorous, Sulfur,
  etc)

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Interdependence

• - Effects of Interactions between organisms
  their environment.
• - Each organism Depends in some way on other
  living and nonliving things in its Environment.

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Key theme of Ecology

• No Organism is isolated- Everything is
  interconnected
• Species interact with each other with abiotic
  factors in the environment.
• Disturbances in one species can affect other
  species.

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Example of Interdependence

• See diagram on page 360 in textbook
• Unexpected chain reaction
• In a year when more acorns are produced-
  eventually see humans with more lyme disease.
• Explain how this happens.
• Can you think of another example of how a change
  in your environment can indirectly affect living
  organisms?

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Some examples of complex, controversial
interactions are not completely understood

• Because they involve
• dynamic ecosystems
• multiple governments
• differing interpretations of data in an area of
  ever-changing science.

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Some Environmental Problems

• 1. Human Population Growth
• 2. Mass Extinction
• 3. What is Climate Change/Global Warming?
• 4. Pollution
• 5. Use of Resources/ Burning Fossil Fuels
• 6. Sustainability

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Graph of Human Population Growth
1. Human Population Growth
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Growth-limiting factors
1. Human Population Growth

• the availability of food and water
• invasion of parasites, pathogens or disease
• over-crowding (increasing competition for food,
  water and space)
• severe or sudden climatic changes
• pollution of air, soil and water

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2. Mass Extinction

• As human population has increased, many other
  species decline in number or become extinct.
• There have been at least 5 periods of mass
  extinction, could we be causing 6?

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What is the greenhouse effect?
3. What is Climate Change/Global Warming?
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3. What is Climate Change/Global Warming?
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Major Greenhouse gases and their sources
3. What is Climate Change/Global Warming?

• H2O (water vapor) evaporation, plant
  respiration.
• CO2 (Carbon dioxide)- burning fossil fuels,
  volcanic eruptions
• CH4 (Methane) -animal waste, fossil fuels,
  landfills, sewage, wetlands
• N2O (Nitrous Oxide) deforestation, fossil
  fuels, microbe activities (in soil)
• CFCs (Chlorofluorocarbons)- aerosols,
  propellants, solvents, refrigerants

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Is Global Warming actually happening?
3. What is Climate Change/Global Warming?

• Many scientists say NO!
• The Cooling World- Newsweek, April 28, 1975
• ( scientists warned in the 1970s that the earth
  was dangerously cooling! www.denisdutton.com/cooli
  ng_world.htm
• 1980s-2006 Global Warming was the politically
  correct topic
• See Al Gore many Hollywood actors opinions.
• In 2007, hundreds of people died, not from global
  warming, but from cold weather hazards
  http//www.washingtontimes.com/article/20071219/CO
  MMENTARY/10575140
• 2008 Independent study commissioned by congress
  
• Mr. Wegman team from George Mason University
  concluded that the idea that the planet is
  experiencing global warming "cannot be
  supported." http//www.washingtontimes.com/apps/pb
  cs.dll/article?AID/20080314/COMMENTARY/702895001/
  home.html

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Concerns if there were global warming
3. What is Climate Change/Global Warming?

• Ecosystem interactions between predator prey
  may change
• Change in breeding times
• Human health issues for increased mosquito
  population.
• Rising sea levels
• Coral Reefs

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If Ice caps were to melt- Rising sea levels
would be a concern to islands like the Maldives.
3. What is Climate Change/Global Warming?
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Coral reefs, the nurseries of many marine
species, would be killed by higher temperatures,
or by a lack of sunlight as sea level rises.
3. What is Climate Change/Global Warming?
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4. Pollution
Pollution Issues An average person may produce a
ton of refuse in a year

• a volume that rapidly overflows local dumps.

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Types of Hazardous Wastes
4. Pollution

• Dyes, Cleaners, Solvents
• PCBs (Polychlorinated biphenyls- from old
  electrical equipment)
• Plastics, Solvents, Lubricants, Sealants
• Toxic Heavy Metals ( Lead, Mercury, Cadmium,
  Zinc)
• Pesticides
• Radioactive Wastes

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-Over 85,000 synthetic chemicals are in use
today, many now known to cause cancer damage to
the brain, nervous, reproductive human hormonal
systems.-An estimated 3-4 million American
Children live within one mile of at least one
hazardous waste site.  Toxicology- The study of
the harmful effects of toxins on organisms
Effects of Toxins on Health
4. Pollution
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Non- Renewable Energy
5. Use of Resources/ Burning Fossil Fuels
Fossil Fuels- the remains of ancient organisms,
changed into coal, oil or natural gas. -central
to modern lifestyle. 2 BIG Problems (1) Supply
is limited (2) Environmental Consequences
March 2008- over 100/barrel
FUEL RESOURCES What is a sustainable energy
source for the future???
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Projected oil production
5. Use of Resources/ Burning Fossil Fuels
http//www.almc.army.mil/alog/issues/JulAug99/MS40
6c2.jpg
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Alternative Energy Sources(Renewable Energy)
6. Sustainability

• Nuclear Energy
• Solar Energy
• Wind Power
• Biomass (methane, ethanol)
• Hydroelectricity-water power
• Geothermal Power- from inside the earth
• Hydrogen Power-
• Tidal Power- using water power for turbines
• OTEC (Ocean Thermal Energy Conversion)

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In Ecosystems- all things are connected

• To appreciate how an ecosystem works- think about
  other things depend on hundreds of individual
  parts.
• If one part is missing or breaks, the entire
  thing does not work.

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BIOSPHERE

• The biosphere is the thin layer of the Earths
  crust with the atmosphere ocean layers that
  support LIFE that includes
• All plant and animal life
• The things that sustain life air, soil and
  water.
• It includes a variety of ecosystems that are
  connected by natural cycles.

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Biosphere- is composed of three parts

• ATMOSPHERE a light blanket of air enveloping
  the earth, with more than half its mass within 4
  miles of the surface and 98 within 16 miles
• HYDROSPHERE --- the surface and subsurface waters
  in oceans, rivers, lakes, glaciers, and
  groundwater,
• LITHOSPHERE --- the upper reaches of the earth's
  crust containing the soils that support plant
  life, the minerals that plants and animals
  require for life and the fossil fuels and ores
  that humans exploit.

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Earth Age About 4.5 Billion Years OldLocation
In the Solar System, on the outer edge of the
Milky Way, about 28,000 light years from the
galactic center
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Some Earth Facts

• Highest Point 29,028 feet
• above sea level, Mount Everest,
• formed 60 million years ago,
• located on the border of Tibet
• Nepal in the Himalayas (Asia).
• Lowest Point (on Land) 1,320 feet below sea
• level, Dead Sea, (middle east) It is so salty --
  the
• saltiest on Earth -- that it is unable to support
  any
• type of life.
• Deepest Point on Earth 35,802 feet, Mariana
  Trench in the Pacific Ocean. The water pressure
  there is over eight tons per square inch.

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Some Earth Facts

• Surface Data 70 covered by water, with the
  remaining 30 composed of the
• 7continental land masses.
• Water Composition
• 97 salt water, 3 fresh water
• (about 2 Is glaciers/ice only.3 of all water
  is usable).
• Air Composition
• 78 nitrogen,
• 21 oxygen,
• 1 other content

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Hierarchical Levels of Organization- Ecology

• Just like the hierarchy of levels of organization
  in organisms, there are also levels of increasing
  complexity in the environment.
• Each level has unique properties that cannot be
  identified just by studying a lower level.
• Each level is influenced by the other levels.

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Levels of Organization

• ORGANISM -Simplest Level of Organization (1
  living thing)
• POPULATION- Includes all the members of the same
  species - that live in one place at a given time
  make-up a breeding group.
• COMMUNITY- Includes all the interacting
  populations in one area.
• ECOSYSTEM- Includes all the living (biotic)
  non-living (abiotic) factors in the environment.
• BIOSPHERE- Thin layer of life around the earth.

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Levels of Organization
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• Examples of populations
• All the bacteria of one All the gorillas
  of 1
• kind on this agar plate species on this
  mountain
• Example of community
• All the organisms living
• Together in this pond

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A Changing Environment

• Abiotic Factors do not remain constant
• Organisms are able to survive in a range of
  conditions.
• Most individuals can survive average conditions

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Tolerance Curve

• A graph showing performance vs. values for a
  specific variable such as temperature for a
  species. (See page 364 textbook)

Example Some bacteria can survive boiling water,
some plants can survive arctic cold. But- Most
organisms can not survive BOTH extremes.
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Acclimation

• Some organisms can adjust their tolerance to
  abiotic factors.
• Examples- YOU adapting to less oxygen in higher
  altitudes
• Goldfish, adapting to new water temperature
• Conformers- organisms that do not regulate their
  internal conditions
• Examples- Lizards, cold blooded organisms
• Regulators- Organisms that use energy to control
  some of their internal conditions to optimum
  range in a variety of conditions.

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Escape from unsuitable conditions

• Ways organisms cope with changes
• Dormancy
• Hibernation
• Estivating
• Migration
• Encysting

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An Organisms Relationship to the Environment

• Niche- The way of life of an organism
• -the status of an organism in its environment
  community (affecting its survival as a species).
• -a position particularly well suited to the
  organism that occupies it.
• - An organisms PROFESSION
• - Includes both biotic and abiotic factors

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The Niche includes

• the range of conditions that the species can
  tolerate,
• the methods by which it obtains needed resources,
  
• the number of offspring it has,
• its time of reproduction
• and all its other interaction with its
  environment.

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Earthworm Niche
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Generalists Specialist Niches

• GENERALIST are species with Broad Niches they
  can tolerate a range of conditions and use a
  variety of resources.
• example opossum- eats a lot of different things
• SPECIALIST. Species that have narrow Niches, such
  as the koala, who only eats 1 kind of leaf.

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Energy Transfer from producers to consumers

• Producers- are Autotrophs that manufacture their
  own food. (grass, plants, phytoplankton)
• Creates Biomass(all the organic material in an
  ecosystem)
• Biomass is the stored energy- the food for the
  rest of the organisms
• Consumers-
• have to eat
• something
• (deer, bear)

http//www.ftexploring.com/ftimages2/dr_br1.gif
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Net Productivity

• Measuring Productivity
• Gross primary productivity is the rate at which
  producers in an ecosystem capture the energy of
  sunlight organic compounds.
• The rate at which biomass accumulates is called
  net primary productivity.
• different BIOMES (Places w/ a distinct climate
  like the tropical rain forest or the desert)
  produce different amounts of biomass.

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Food Chains and Food Webs

• A single pathway of energy transfer is a food
  chain.
• A network showing all paths of energy transfer is
  a food web.
• -Trophic level- an organisms relative position
  in the sequence of energy transfer in a food
  chain or web (who eats what)
• Producers very many in
• Primary Consumers .many
• Secondary Consumers ..fewer
• Tertiary Consumersfewest organisms

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Food Chain Food web in an Antarctic Ecosystem
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Energy Transfer

• Ecosystems contain only a few trophic levels
  because there is a low rate of energy transfer
  between each level.

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Trophic levels
10s 100s 1000s millions
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Biochemical cycles

• Matter must be recycled reused.
• Water -evaporation, transpiration, precipitation
  
• Carbon- photosynthesis, cellular respiration,
  role of autotrophs, consumers, decomposers
• Nitrogen-note role of Nitrogen-fixing bacteria
  plants
• Calcium Phosphorous- moves from rocks to soil
  to organisms to the oceans.

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Your Assignments

• Draw each of the 4 cycles.
• Label all parts of each drawing (40 points)
• Questions Write in complete legible sentences
  or I will not grade them
• Answer 8 questions in sect. 4 (p 374)
• Chapter review questions 7-20 on page 376 ( 20
  points)

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Water cycle Carbon cycle
Nitrogen cycle