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Title: Ecology

Unit II
  • Ecology

  • Ecology is the scientific study of interactions
    among organisms and between organisms and their
  • To understand the relationships within the
    biosphere, we have to ask questions that range
    from an individual to the entire biosphere

Levels of Organization
  • Species a group of organisms similar to one
    another that breed and produce fertile offspring
  • Population groups of individuals that belong to
    the same species in the same area
  • Communities assemblages of different
    populations of different species that live
    together in a defined area
  • Ecosystem collection of organisms that live
    together in a particular place, together with the
    physical environment
  • Biome a group of ecosystems that have similar
    climate and similar dominant communities

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Levels Within Levels
  • An ecosystem is a collection of all the organisms
    that live in a particular place, together with
    their nonliving, or physical, environment. Within
    an ecosystem, there are several levels of
    organization. Your school and its grounds are
    similar to an ecosystem.
  • What living things are found in and around your
  • What nonliving things are found in your school?
  • Into what large groups are the students in your
    school divided?
  • Into what smaller groups are these large groups
  • Are these groups ever divided into even smaller
    groups? If so, what are these groups?

Earths Biosphere
  • The Biosphere spans from 8km above the earths
    surface to 11km below the oceans surface
  • In addition to the biotic portion (i.e.
    populations of organisms) the biosphere is made
    up of three (3) major divisions of abiotic
  • Lithosphere the soil and rock or earths crust
  • Atmosphere the gases surrounding the earth
  • Hydrosphere all of earths water, whether
    gaseous, liquid or solid
  • Note Biotic refers to living and abiotic refers
    to non-living

  • The earth is considered a closed system, a system
    in which nothing enters or leaves
  • Apart from energy from the sun
  • Of all the light energy that strikes the Earths
    surface, only 0.06 is used by producers to
    convert into chemical energy through
  • That 0.06 is enough energy to create 170 billion
    tons of new organic matter per year!

Energy Flow
  • Sunlight is the primary source of energy for life
    on earth some organisms however are able to use
    energy stored in inorganic chemical compounds
  • Ex. the fresh minerals spewed from deep undersea
    geysers sustain life where light does not exist
  • An organism that produces its own food from
    sunlight are called autotrophs because they make
    their own food the common name for these
    organisms is producers
  • Photoautotroph energy from the sun
  • Chemoautotroph energy from inorganic chemicals

  • Photosynthesis is the process by which light
    energy is used to power chemical reactions that
    convert carbon dioxide and water into oxygen and
    energy rich carbohydrates
  • General equation
  • CO2 H2O light energy? carbohydrate O2
  • when chemical energy is used by chemosynthetic
    organisms instead of light, it follows a similar

  • Organisms that rely on consuming other organisms
    are called heterotrophs the common name is
  • Herbivore organisms that eat only producers
  • Carnivores organisms that eat only other
  • Omnivores organism that eat both producers and
  • Energy flows in one direction only, from the sun
    or inorganic compounds to the autotrophs and then
    through various heterotrophs

  • Food chain a series of steps in which energy is
    transferred from producer through various levels
    of consumers by eating or being eaten
  • Food Web in most ecosystems, feeding
    relationships are not so simple some producers
    are consumed by more than one organism, and that
    organism in turn takes part in many different
    food chains. A food web links all the food
    chains in an ecosystem together

  • Each step in the food chain is called a trophic
  • Producers are always the first trophic level

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Ecological pyramids
  • A pyramid has wide base that get progressively
    narrower as it approaches its vertex
  • An ecological pyramid is a diagram that shows the
    relative amounts of energy or matter contained
    within each trophic level
  • Pyramid of Energy describes the relative amount
    of chemical energy at each trophic level
  • 10 rule only about 10 of the energy at each
    trophic level moves on to the next level
  • Question Where does the other 90 go?
  • Answer organisms use that energy during life
    processes such as locomotion, respiration and

  • Biomass Pyramid represents the total amount of
    living tissue within a given trophic level it
    also represents the amount of potential food
    available at each level
  • Usually expressed in terms of grams organic
    matter per unit area
  • Pyramid of Numbers based on the actual number of
    individual organisms at each trophic level
  • This can easily differ from the other pyramids,
    as in a forest ecosystem, a single tree may
    sustain a multitude of other organisms which
    consume it

Pyramid of Numbers Shows the relative number of
individual organisms at each trophic level.
Energy Pyramid Shows the relative amount of
energy available at each trophic level.
Organisms use about 10 percent of this energy
for life processes. The rest is lost as heat.
Biomass Pyramid Represents the amount of living
organic matter at each trophic level.
Typically, the greatest biomass is at the base
of the pyramid.
Its Raining, Its Pouring
  • How many times have you had to change your plans
    because of rain? It probably didnt help if
    someone tried to cheer you up by saying, But we
    really need the rain. However, rain is
    important. If it didnt rain, how would living
    things on land get water?
  • When rain falls on the ground, it either soaks
    into the soil or runs across the surface of the
    soil. When rainwater runs across the land, what
    body of water might collect the rain?
  • From here, where might the water flow?
  • After the rain, the sun comes out and the land
    dries. Where does the water that had been on the
    land go?
  • Construct a diagram that would illustrate all the
    places a molecule of water might go. Begin with a
    raindrop and end with a cloud.

Recycling in the Biosphere
  • Unlike the unidirectional flow of energy in the
    biosphere, all matter is recycled within and
    between ecosystem through biogeochemical cycles
    these cycles include
  • Water Cycle
  • Carbon Cycle
  • Nitrogen Cycle
  • Phosphorous cycle
  • Question Why are these cycles important for
  • Answer recall Unit 2, four major groups of
    organic compounds include carbon, hydrogen,
    oxygen, nitrogen and phosphorous

Water cycle
  • The process where surface water enters the
    atmosphere is called evaporation water can also
    enter the atmosphere through the leaves of plants
    through a similar process called transpiration
  • As the warm air rises it begins to cool,
    condensation is when the water vapor begins to
    coalesce into tiny droplets that form clouds
  • When these droplets reach a critical size the
    become precipitation and rain down to earth

  • After falling to earth, water enters many
    different systems, and flows from one system into
    another a few of these systems include
  • Ground water the water seeps underground and
    accumulates into vast reservoirs in porous rock
  • Running water it may enter a stream or lake that
    eventually enters a large body such as an inland
    sea or ocean
  • Plants enters through roots and cycle begins
  • DYK about 1/3 of all precipitation on land is
    lost to the ocean through runoff?

Root Uptake
Nutrient Cycle 1Carbon Cycle
  • Carbon is a naturally occurring element on earth
  • 4 processes move carbon around in the biosphere
  • Biological processes such as photosynthesis,
    respiration and decomposition, take up and
    release carbon and oxygen
  • Geochemical processes such as erosion and
    volcanic activity may release carbon into the
  • Mixed biogeochemical processes the burial of
    ancient organisms, and their conversion into
    fossil fuels deep underground
  • Human Activities mining, cutting, burning
    forests and fossil fuels
  • Video 2

  • What are the main sources of CO2 in the earths

Nutrient Cycle 2Nitrogen Cycle
  • All organisms require nitrogen to make amino
    acids and nucleotides.
  • Nitrogen makes up 78 of the Earths atmosphere
  • Nitrogen is brought into the soil through natural
    processes (lightning) or biological processes
    (nitrogen-fixing bacteria) in the form of ammonia
    Video 1
  • Ammonia (NH3) is toxic, so nitrifying bacteria
    living in the soil convert it into the less toxic
    form of nitrate (NO3)
  • De-nitrifying bacteria destroy both of these
    types of nitrogen compounds, sending it back into
    the air (this prevents a toxic buildup in the
  • Nitrates are taken up by plants and enter the
    food chain in the form of proteins and nucleic
  • Video 2

  • Nitrogen is naturally fixed by rhizobium bacteria
    that live in symbiosis with the root systems of
    plants plants supply the carbohydrates, bacteria
    provide the nitrogen, its win-win for both
    organisms involved! Video 3
  • Nitrogen is the key component of artificial
  • Nitrogen is a limiting nutrient in agricultural
    systems, the more nitrogen you can put in, the
    greater your return
  • Limiting nutrients limit the growth and
    development of the organisms in the region
  • Soil erosion carries this fertilizer off farmers
    fields and into wild ecosystems, where it
    violently upsets the balance of these ecosystems
    creating dead zones, and also entering the
    human water supply

Nutrient Cycle 3Phosphorous Cycle
  • Video 1 Dead Zone 2
  • Phosphorous Cycle is a sedimentary cycle, meaning
    the atmosphere does not play a significant role
    in this cycle
  • Phosphorous as a mineral enters the ecosystem
    through erosion, the process whereby weathered
    rock is transported via water
  • This mineral enters living systems through
    plants, and works its way through the trophic
    levels, finally ending up back in the soil
    through death or waste produced
  • This nutrient plays a huge role in stimulating
    algae growth in lakes and coastal regions, which
    eliminates oxygen, choking out all other life
    forms creating a dead zone

  • The key elements of Life have a direct relation
    to these cycles
  • C Carbon Cycle
  • H O Water Cycle
  • N Nitrogen Cycle
  • P Phosphorous cycle
  • Video

Nutrient Limitation
  • Ecologists study the primary productivity of an
    ecosystem, the rate at which organic matter is
    created by producers
  • If one or more of the nutrients necessary for
    life is in short supply, it will limit the growth
    and reproduction of an organism
  • When an ecosystems growth is limited by a the
    scarcity of a nutrient we call it a limiting

  • Question What may be the limiting nutrient in
    the desert?
  • Answer Water!
  • Question What are the major limiting nutrients
    to growing plants in Saskatchewan? How do we
    overcome these limits?
  • Answer Nitrogen, Phosphorous and Potassium we
    overcome these limits by supplementing the
    existing nutrients of the soil with fertilizers
    containing additional nutrients.

In-Class Assignment
  • On a new piece of loose-leaf paper from your
    binder, complete the activity Farming in the
    Rye on p.79 of your textbook.
  • Complete the 4 problems listed and hand-in by the
    end of class.

Chapter 3 Assignment
  • Complete Chapter 3-x assessment questions
  • 3-1 2, 3
  • 3-2 1-5
  • Also Focus on the Big IdeaInterdependence in
  • 3-3 1-6

Ecosystems and Communities
  • Weather is the day to day condition of Earths
    atmosphere at a particular time and place
  • Describe the weather today
  • Climate refers to the average, year-after-year
    conditions of temperature and precipitation in a
    particular region
  • Describe the Climate of Regina

  • Question Why is it that some planets surface
    temperature varies by 500 degrees or more
    depending on day or night, but Earth doesnt?
  • Answer Our atmosphere regulates surface
    temperature through the Greenhouse Effect

  • Quickly sketch a diagram of the Greenhouse effect
    in your notebook

  • Question Does your proximity to the equator
    affect the amount of sunlight you receive?
  • Answer Yes, the closer you are to the equator,
    the greater the intensity of light the further
    you are from the equator the greater the angle of
    incidence (more spread out), which results in
    receiving less light energy

What shapes an ecosystem?
  • An ecosystem is characterized by its
    characteristic biotic and abiotic factors
  • List 3 examples each for possible biotic and
    abiotic characteristics of a Pond ecosystem
  • These factors determine the survival and growth
    of an organism and the productivity of the
    ecosystem in which that organism lives
  • The area where an organism lives is called a

  • If a habitat is an organisms home address, then a
    niche is its occupation
  • A niche is the full range of physical and
    biological conditions in which an organism lives
    and the way in which that organisms uses those
  • Question What are some of these conditions?
  • Answer temperature and moisture requirements,
    the food it eats, how it obtains food, which
    other organisms consume the for food, where it

Fitting In
  • Organisms not only live together in ecological
    communities, but they also constantly interact
    with one another. These interactions, which
    include predation and competition, help shape the
    ecosystem in which they live.
  • Based on your own experiences, define predation.
    Give one example of predation.
  • Based on your own experiences, define
    competition. Give one example of competition.

Ecological Interactions
  • Competition occurs when an organism of the same
    or a different species attempt to use a resource
    in the same place at the same time
  • Resource any necessity for life, water,
    nutrients, light, food or space
  • The competitive exclusion principle states that
    no two species can occupy the same niche in the
    same habitat at the same time one species will
    be forced to emigrate or go extinct

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  • Predation where one organism feeds on another,
    killing it in the process
  • Symbiosis any relationship whereby two species
    live closely together further split into three
    main categories
  • Mutualism both species benefit from the
  • Commensalism one species is helped, the other is
  • Parasitism one organism lives on or inside
    another organism, harming the other organism in
    the process

Ecological Succession
  • Ecosystems are constantly changing in response to
    natural and human disturbances. As an ecosystem
    changes, its older inhabitants die out and new
    organisms move in, causing further changes to the
  • The series of predictable changes that occurs in
    response to these disturbances is called
    ecological succession

  • Primary Succession occurs where no soil exists
    typically occurs after a devastating change, such
    as a volcanic eruption or a bare rock beneath a
    quickly receding glacier
  • After an island is built through geological
    processes, primary succession includes a pioneer
    species, the first species to populate the area.
  • Lichens are typically a pioneer species they are
    composed of an algae and a fungus living as
    mutualistic symbiotes, and can grow on and break
    down bare rock into soil

  • Secondary Succession follows a less significant
    disturbance, that typically leaves the soil
    intact such as a forest fire or farming
  • Nearby community interactions tend to restore the
    ecosystem to original conditions
  • it was only recently discovered that forest fires
    play a vital role in maintaining the health of
    ecosystems, by eliminating older and diseased
    trees and activating many seeds on the forest
  • Prescribed burns are now performed in parks
    across Canada as a means to maintain the health
    of the forest.
  • Some human disturbances will permanently
    eliminate members of an ecosystem and alter it
    forever to a point where it may not recover.

  • Succession in marine Systems varies enough to get
    its own category we will refer to this as a
    whale-fall community
  • On the seafloor there is no light, but still
    organisms exist with the express purpose of
    decomposition and returning the nutrients into
    the upper ecosystem
  • Should a large body (such as a whale) fall to the
    ocean floor
  • Scavengers such as hagfish and sharks will
    consume the flesh of the organism
  • Once picked clean, the carcass can no longer
    support a large community however the
    surrounding sediment is enriched with nutrients
    that support a variety of worms and other
  • Chemosynthetic bacteria will consume the skeletal
    remains, who in turn are the producers for a food
    chain that includes mussels, snails and crabs.

  • Biology Worksheet
  • Examining the Stages in Ecological Succession
  • Receive Worksheet complete using remaining class
  • Due Date 2 Class days hence

  • Complete the online activity
  • Active Art Assessment BIOMES
  • The web link can be found on p.99 of your text
  • When finished, use the remainder of the period to
    complete the attached Crossword Communities
    and Biomes

  • Create a Chart in your notebook that includes the
    following headings
  • Name of Biome
  • Temperature
  • Precipitation
  • Soil Type
  • Dominant Plants
  • Dominant Animals
  • Other Notable Characteristics
  • Read 4-3 and 4-4 pp.98-105 and fill in the chart
    as described above
  • Hints turn your page widthwise for the table
    leave yourself plenty of space for your answers
    the table may stretch onto a second page

  • Complete the Activity Analyzing Data Ecosystem
    Productivity on p.111 on a separate piece of
  • Complete questions 1-4
  • Due Date 1 class day hence

Chapter 4 Assignment
  • Read through Chapter 4 and complete the following
    questions from the section Assessments
  • 4-1 1-4
  • 4-2 1-5 including Writing in Science
  • 4-3 2-6 including Focus on the Big Idea
  • 4-4 1-5 including Writing in Science
  • The underlined portions of this assignment should
    be completed with care and attention to detail,
    as they will be evaluated for quality at the
    conclusion of this Unit

Unit 2 Part 1
  • We are going to split our Ecology Unit into two
    parts we will assign a review and write an exam
    for this Unit that will correspond to Chapters 3
    and 4 in your textbook

  • Chapter 3 Review
  • Read Study Guide (p.82) and complete the
    following problems from the following Chapter
  • 1-10, 26-30

  • Chapter 4 Review
  • Read Study Guide (p.114) and complete the
    following problems from the following Chapter
  • 1-10, 26, 27, 29-33

  • Complete the Inquiry Activity How Populations
    Grow? from p.118 in your text
  • each What is the rate of growth year?
  • Pairs of rabbits (2)
  • Each pair makes six bunnies (x6)
  • Net increase each generation of rabbit increases
    by a factor of 3 (triples)
  • When graphing your data, use the entire y-axis,
    each square equals 10 rabbits.
  • Label your graph appropriately (title, label for
    each axis, etc.)
  • Complete Question 1-3

Year 1st 2nd 3rd 4th
rabbits 6 18
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Activity Review
  • Question Once the original pair of rabbits began
    multiplying, what would happen to the plant
  • Answer they would decrease at equal rates
  • Question If rabbits began to die off, what would
    happen to plant populations?
  • Answer they would begin to increase, as there
    would be fewer rabbits around to eat them.

Biotic Potential
  • The size a population would reach given unlimited
    resources and space
  • The factors that prevent this ideal growth are
    called limiting factors
  • List some potential limiting factors

  • FYI Use text to discover the answers to the
    following questions. These answers are your
    notes for this section. ? no need to copy this
  • Question What are the three most important
    characteristics of a population
  • Answer Geographic distribution, density growth
  • What 3 factors affect population size?
  • Answer Number of deaths, number of births,
    number of individuals entering or leaving the

  • Question What is the difference between
    exponential and logistic growth?
  • Answer exponential growth occurs when a
    population grows at a constant rate occurs with
    unlimited space and food, with the absence of
    disease and predators). Logistic growth occurs
    when population growth slows or stops completely
    after a period of exponential growth.
  • Question What is carrying capacity?
  • Answer when population growth equals zero
    (logistic growth) this represents equilibrium,
    when a population is in balance with its
    environment. (birthsdeaths)

Making Connections
  • Population Density can be described
    mathematicallyPopulation Density of
    Individuals Area
  • Question Suppose there are 150 bullfrogs living
    in a pond that covers an area of 3 km2. What is
    the density of the bullfrog population?
  • Answer 150bullfrogs / 3km2 50 bullfrogs/km2

In-Class Assignment
  • Complete Analyzing Data on p. 123.
  • Graph paper is available
  • Answer questions 1-4
  • When complete, staple or paperclip your
    assignment together and hand in
  • Complete Thinking Visually, create a concept
    map of all terms in your notebook

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Limits to Growth
  • Question Look at Fig. 5-5 (p.124) how might
    each of these factors increase the death rate of
    a population?
  • Possible Answers Include
  • Competition lesser fit individuals are unable to
    get resources they need to survive
  • Predation individuals are consumed
  • Parasitism Disease individuals become less
    fit/dead as a result of infection this prevents
    them from consuming necessary resources
  • Drought, etc. access to resources (water, food)
    limited, individuals starve to death
  • Human Disturbances access to space, food, clean
    water becomes restricted toxins introduced to

  • Wolf and Moose Populations on Isle Royale
  • Describe the relationship you observe between
  • Question What is the difference between
    density-dependent and density-independent
  • Answer Competition, predation and
    parasitism/disease are all natural components to
    ecosystems, members of that biome. These are
    natural mechanisms within the biome to control
    populations and as a result they are
  • Unusual weather and human interference are
    examples of density independent factors. They
    can occur at any time and serve no natural
    purpose for the health of the Biome.

Human Population Growth
Question if you extended this graph hundreds of
years into the future, what would it look like?
  • Like populations of many other living organisms,
    the size of the human population tends to
    increase with time.
  • Question How did the human population manage to
    increase as much as it did?
  • Answer
  • advances in medicine decreased death rate, and
    fewer infant mortalities increased the birth rate
  • The availability of food and water supported
    larger families

  • A demographic transition is a dramatic shift in
    birth and death rates.
  • With advances in medicine, nutrition, education
    and sanitation, more children survive to
    adulthood, and more adults live to a old-age
  • When death rates fall, birth rates typically
    remain the same, and as a result our population
  • Did you know Our generation will be the first in
    human history to have a lower life expectancy
    than our parents generation since the bubonic
    plague? What plague are we experiencing now?

Answer The united states is about 6, and in
Rwanda about 14.
Question How do the United States and Rwanda
differ in the percentages of 10-14 year olds in
their population?
  • Question What factors might influence why
    populations in different countries grow at
    different rates?
  • Answer birth rates, death rates and age
    structure of population.
  • Describe the demographic transition and explain
    how it might affect a countries population
  • Answer When it begins, both birth and death
    rates are high. As death rates fall due to
    advances in medicine, nutrition, etc the
    birthrate will remain high. The population will
    adapt to this and eventually the population will
    level out as birth rate slows and even stops.

  • Why do age structure diagrams help predict future
    population trends?
  • Example In Canada, we have a very large elderly
    population, what can you predict about birth and
    death rates in the near future? Do the elderly
    give birth? Are they at greater risk of death
    than others?
  • Answer Diagrams include data on younger
    individuals in age groups that will contribute to
    population growth as members of those groups

Chapter 5 - Review
  • Read and complete the following
    sections/questions from Chapter 5
  • 5-1 3-5
  • 5-2 1-5
  • 5-3 1, 2, 4, 5

Humans in the Biosphere
  • Watch Video Justicia Now
  • Questions to follow video
  • Copy and complete the following questions in your
  • What impact did oil exploration and exploitation
    have on the environment and surrounding
    indigenous communities?
  • What are 3 things you learned from this video?
  • Why do you think the companies involved get away
    with these crimes? Does this happen in Canada?
    Explain how it should be dealt with in Canada.

6-1 A Changing Landscape
  • While reading this section, create a 2 column
    Chart like the following

Types of human activities Impact
Ex. Hunting and Gathering Ex. Caused major mass extinction of species such as mammoths and Giant Sloths
  • What are some of the disadvantages of relying on
    hunting and gathering for your food?
  • Answer You may have to move your home to follow
    the animals that sustain you without being cared
    for by humans, some beneficial plants may die due
    to drought or competition with other plants.

  • What are some advantages to using agricultural
    machines such as tractors and combines?
  • Answer vast acreages can be plowed, sown, and
    harvested in less time and with fewer people,
    enabling farmers to produce crops on a large
  • Are there any disadvantages?
  • Answer Initial cost? Repairs and maintenance?
    Increased consumption of energy, exhaust gases
    released to environment, noise, etc.

Exam Question from this Section
  • Fill in the chart below

Type of Human Activity Impact on the Environment
Hunting Gathering
Green Revolution
  • Cities and Suburbs can grow out of control, and
    be so sprawled out that we run into problems.
    What are these problems and how can they be
  • Answer
  • Wastes ? reduce reuse recycle!
  • Put a cap on how big a city should be able to
    grow outwards (daily commutes in cities like
    Toronto and Calgary are atrocious!)
  • Other ideas?

Historical footnote
  • Norman Borlaug was born on a farm. After
    Receiving his doctorate in Plant Pathology from
    university, he became director of a program in
    Mexico that focused on breeding new and improved
  • In the years that followed, The International
    Maize and Wheat Center near Mexico City, Norman
    was successful at creating new strains/breeds of
    wheat and corn that were able to withstand
    disease and drought with relatively high yields
    (yield is how much grain you get from a given
  • By the 1960s his strains were being planted
    throughout the world, especially in famine
    wracked nations such as India and Pakistan. He
    received the Nobel Peace Prize for his work.

  • How has an understanding of Biology helped
  • Potential Answers creating new crops that can
    survive harsh climates, enriching crops with
    vitamins to prevent blindness others?
  • Does this area of study still occur today?
  • Answer Yes! For example University or
    Saskatchewan created a strain of rapeseed nearly
    50 years ago and called canola, this is big
    business! U of S is the premier university in
    the world for agricultural research, a very
    profitable science that benefits the world

  • Read 6.1 from your text
  • Answer Questions 3, 5 on p. 143

6-2 Renewable and Non-Renewable Resources
  • Read aloud introduction
  • Question What is the tragedy of the commons?

Trading forests for food
  • During the past 200 years, our neighbours to the
    south (USA) have had their forest lands reduced
    by about 20 This amounts to an area roughly the
    size of Texas
  • Worldwide, forests have been reduced in size by
    20 in the last 30 years much of this has been
    cleared in order to grow crops
  • The impact of reducing forest cover can include
    more severe destruction from natural disasters
    (forests prevent floods and absorb force from
    hurricanes and tsunami), a reduction in
    biodiversity, less rain and increased CO2 in our

  • World fisheries are regions where fish are
    harvested industrially
  • In 2000, the world catch was almost 95 million
    metric tons. 86 million came from our oceans.
  • World aquaculture amounted to nearly 36 million
  • The top 3 types of fish were sardine, herring
    anchovies at about 25 million metric tons
  • The leading countries who fish are China, Peru,
    Japan, India, USA, Indonesia, Chile and Russia
  • Pacific Ocean fisheries account for about ½ the
    worlds fish catch

  • How does Biological pest control contribute to
    sustainable development?
  • Answer It does not create pollution that can
    enter the food chain and harm other organisms

  • What are two ways in which reforestation might
    affect the biosphere?
  • Answer It would prevent further soil erosion
    (which creates relatively lifeless deserts) and
    would reduce global atmosperic CO2 (greenhouse

  • Describe the History of the Cod population in
    Georges Bank between 1980 and 2000.
  • Answer in 1980 there were 80,000 tons of cod.
    That total dropped until the late 80s when
    stocks rebounded somewhat. In the early 90s
    stocks dropped significantly, only to begin a
    slow rise.
  • By 2000, the amount of fish was less than 1/3 the
    amount present in 1980

Interactive Fisheries Activity!(
cbp-2062 (p.147)
  • Copy out the following questions onto a separate
    piece of paper in your notebook
  • Were you able to reach your target population by
    changing any single parameter?
  • Which parameter did you change that got you
    closest to your goal?
  • Is it possible to improve the spawning stock
    biomass by setting only one kind of limitation on
    the fishing industry?
  • Once the spawning stock biomass has reached its
    goal do you think that limitations should still
    be put on the fishing industry in future years?

  • What pathways do the chemicals in the atmospheric
    emissions take on their way to becoming acid
    rain? (figure 6-12)
  • Answer The gases combine with water vapor to
    form drops of nitric acid and sulfuric acid,
    which can drift long distances before they fall
    to the ground as rain.

  • Read Section 6-2
  • Complete problems 1, 2, 3, 5 (p.149)

6-3 Biodiversity
  • Predict the definitions of the following terms
    using the underlined term in each.
  • Habitat fragmentation
  • Invasive species
  • Biological magnification

  • How is the illustration of DDT concentration the
    opposite the pyramid of numbers to the left in
    fig. 6-16 (p. 152)?
  • Answer Its like an upside down pyramid the
    concentration of pollution is very small at the
    bottom, and gets bigger as it moves up
  • By What number is the concentration of DDT
    multiplied by at each successive trophic level?
  • Answer 10

Historical Footnote
  • DDT (dichlorodiphenyltrichloroethane) was first
    synthesized chemically in the lab during the
  • It was used during WWII to kill the lice and
    ticks that carried the disease typhus, and later
    to kill mosquitoes that carried the disease
  • DDT is exteremely effective at killing these
    disease-carrying insects, however the problem is
    that DDT is so stable it doesnt degrade over
    time or break down easily (like a twinkie!)
  • To this day it persists in our ecosystems,
    continuing to drive higher level consumers likes
    hawks and eagles to extinction

  • DYK ? Most of last centuries DDT is trapped in
    the polar ice caps? The accelerated melting of
    these caps observed in the last decade has
    resulted in the release of tons of DDT back into
  • Question What is being released by melting polar
  • Answer DDT and other man-made chemicals, along
    with CO2 trapped in the ice is being released
    which creates a GHG feedback loop dissolved
    elements and minerals such as the toxin arsenic
    are also released

Tragedy in Minamata
  • A tragic example of biomagnification involved
    mercury, a byproduct of the production of
    batteries, fluorescent light bulbs and mining to
    name a few.
  • In humans, mercury affects the central nervous
    system (brain and spine), causing paralysis,
    mental illness and death.
  • Many years ago, factories located around Minimata
    Bay in Japan disposed of mercury into the ocean
    (many people still consider it a big garbage can)
  • this dissolved mercury was absorbed by
    phytoplankton and passed up the food-chain
    eventually it reached dangerous concentration in
    larger fish such as Swordfish and Tuna

  • Because much of their diet included fish, local
    Japanese populations ingested this mercury, many
    became terribly ill and died, others had
    physically deformed and mentally retarded
  • This tragedy is an example of why careful
    scientific study are needed before disposing of
    waste in the environment
  • Question Why is it still recommended people
    consume no more than 1 tin of Tuna per week?
  • Answer Tuna remain contaminated even after
    several decades of proper disposal of mercury

Guided Reading
  • During your provided reading time, I will ask
    questions regarding each heading. I will space
    my questions out 3-5 min. Please pause your
    reading when asked each question.
  • What is the value of biodiversity? (hint fig.
  • Why are habitat alterations a threat to
    biodiversity? (see fig 6-15)
  • Why does pollution become more concentrated as it
    moves through the food chain?
  • Why are introduced species a threat to
    biodiversity? (see fig 6-17)

  • Read 6-3
  • Complete problems 1, 2, 3, 5, 6

How Much Should It Cost?
  • You may have read that when something becomes
    hard to obtain, its price usually increases. Such
    is the case for materials like gold and diamonds,
    which are nonrenewable resources. Using similar
    thinking, some researchers believe that all the
    valuable services provided by a healthy ecosystem
    should be assigned a dollar value.
  • Rank the following items in order of their
    importance to you. Then, next to each item, write
    down how much you would be willing to pay for it.
  • Fresh, clean drinking water
  • Clean air to breathe
  • An endangered plant containing a substance that
    can cure cancer
  • Gas for your family car

6-4 Charting a Course for the Future
  • Question What would happen to the temperature
    of the atmosphere if the amount of greenhouse
    gases increased?
  • Answer Like wearing a parka in the summer, the
    atmosphere would become warmer hence Global
  • QuestionWhat action did nations take to deal
    with the ozone hole?
  • Answer Many nation reduced, then finally banned
    the production and use of CFCs

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Ecosystem Services
In-Class Assignment
  • Complete Analyzing Data (p.158) on a piece of
    paper separate from your notes. Hand-in by the
    end of class. This is NOT a group activity.

  • Read 6-4
  • Complete Problems (p.160) 1, 2, 3

End of Ecology Unit
  • Important Dates
  • Open-book ecology exam Thursday April 9th
  • Closed-book Midterm Exam Friday April 24th
  • The unit of Study to follow focuses on Evolution
    and the Classification of Life

Ecology Review
  • Ch. 5 Populations
  • Complete Assessment Problems on p. 135
  • 1-10, 24, 25, 27-32
  • Review Problems
  • Ch. 6 Human Impact on the Biosphere
  • Complete Assessment Problems on p.163
  • 1-11, 22, 24, 25, 29-31
  • Review Problems

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