Topic 5 and Option G - Ecology

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Topic 5 and Option G - Ecology
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5.1 Communities and Ecosystems

• 5.1.1
• Define (1)
• Ecologythe study of relationships between living
  organisms and between organisms and their
  environment.
• Ecosystema community and its abiotic
  environment.
• Populationa group of organisms of the same
  species who live in the same area at the same
  time.
• Communitya group of populations living and
  interacting with each other in an area.
• Speciesa group of organisms which can interbreed
  and produce fertile offspring.
• Habitatthe environment in which a species
  normally lives or the location of a living
  organism.

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5.1 Communities and Ecosystems

• 5.1.2
• autotroph (producer) organisms that use an
  external energy source to produce organic matter
  from inorganic raw materials
• Examples trees, plants, algae, blue-green
  bacteria
• What process are they doing????

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5.1 Communities and Ecosystems

• heterotroph (consumer) organisms that use the
  energy in organic matter, obtained from other
  organisms
• Examples ????

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5.1 Communities and Ecosystems

• consumers feed on other living things
• detritivore feed on dead organic matter by
  ingesting it
• saprotroph (decomposer) feed on dead organic
  material by secreting digestive enzymes into it
  and absorbing the products
• So, whats the difference here???

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5.1 Communities and Ecosystems

• 5.1.4
• Describe what is meant by a food chain giving
  three examples, each with at least three linkages
  (four organisms). (2)
• A food chain is a sequence of relationships
  between trophic levels where each member feeds on
  the previous one.
• Dont include decomposers in your food chain in
  your notes.

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5.1 Communities and Ecosystems

• 5.1.5
• Describe what is meant by a food web. (2)
• A food web is a a diagram that shows the feeding
  relationships in a community. The arrows
  indicate the direction of energy flow.

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5.1 Communities and Ecosystems

• 5.1.6
• Define trophic level. (1)
• A trophic level is where an organism is
  positioned on a food web (its feeding
  relationship to other organisms).
• Producer
• Primary consumer
• Secondary consumer
• Tertiary consumer

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5.1 Communities and Ecosystems
Quaternary consumers

• 5.1.7
• Deduce the trophic level of organisms in a food
  chain and a food web. (3)

Carnivore
Tertiary consumers
Carnivore
Secondary consumers
Carnivore
Primary consumers
Herbivore
Primary producers
Plant
A terrestrial food chain
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5.1 Communities and Ecosystems

• 5.1.9
• State that light is the initial energy source for
  almost all communities. (1)
• What process???

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• 5.1.10
• Explain the energy flow in a food chain. (3)

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• 5.1.11
• State that energy transformations are 1020
  efficient. (1)

That means used for more biomass.
Math Check!
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• 5.1.12
• Explain what is meant by a pyramid of energy and
  the reasons for its shape. (3)

Notice the loss of energy with each transfer in a
food chain
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5.1 Communities and Ecosystems

• 5.1.13
• Explain that energy can enter and leave an
  ecosystem, but that nutrients must be
  recycled. (3)
• Energy enters as light and usually leaves as
  heat.
• Nutrients do not usually enter an ecosystem and
  must be used again and again. Nutrients include
  Carbon, Nitrogen, and Phosphorus

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Nitrogen Cycle
N2 in atmosphere
Assimilation
Denitrifying bacteria
NO3
Nitrogen-fixing bacteria in root nodules of
legumes
Decomposers
Nitrifying bacteria
Ammonification
Nitrification
NO2
NH4
NH3
Nitrogen-fixing soil bacteria
Nitrifying bacteria
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G1 Community Ecology

• G.1.1 Outline the factors that affect the
  distribution of plant species, including
  temperature, water, light, soil pH, salinity, and
  mineral nutrients.

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G1 Community Ecology

• G.1.2 Explain the factors that affect the
  distribution of animal species including
  temperature, water, breeding sites, food supply
  and territory.

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Internal Assessment

• Think about what will effect how plants are
  distributed in an ecosystem.
• First IA pause and Statistics Pause.

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G1 Community Ecology

• G.1.5 Explain what is meant by the niche concept.
• The total of a species use of biotic and abiotic
  resources is called the species ecological
  niche.
• Habitat
• Feeding relationships
• Symbiotic/other interactions with organisms

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G1 Community Ecology

• G.1.7 Explain the principle of competitive
  exclusion.
• two species competing for the same limiting
  resources cannot coexist in the same place one
  must leave or becomes extinct

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G1 Community Ecology

• G.1.8 Fundamental vs Realized Niches
• Fundamental where the species is designed to
  live the best
• Realized where the species actually resides
  because of competition

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G1 Community Ecology

• G.1.6 Outline the following interactions between
  species competition, herbivory, predation,
  parasitism, and mutualism (with examples).

Research time!
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G1 Community Ecology

• G.1.9 Define biomass - each tier represents the
  dry weight of all organisms in one trophic level

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G2 Ecosystems and biomes

• G.2.1 Define gross production and net production.
• Gross Production the amount of light energy
  converted to chemical energy by autotrophs in an
  ecosystem
• Net Production Energy able to be passed on by
  producers to consumers
• G.2.2 GP R (Respiration) NP

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G2 Ecosystems and biomes

• G.2.5 Construct a pyramid of energy, given
  information.

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G2 Ecosystems and biomes

• G.2.6 Distinguish between primary and secondary
  succession.
• Primary succession occurs where no soil exists
  when succession begins
• Secondary succession begins in an area where soil
  remains after a disturbance

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G2 Ecosystems and Biomes

• G.2.7 Outline the changes in species diversity
  and production during primary succession.
• Not very diverse Lichen pioneer species
• Very diverse Forest climax community

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G2 Ecosystems and Biomes

• G.2.8 Explain the effects of living organisms on
  the abiotic environment, with reference to the
  changes occurring during primary succession.
• Small amount of soil formed by the lichens is
  colonized by mosses, which do not have roots and
  require little soil
• As the seedless plants live and die
  decomposition increases the richness of the soil
• Grasses can successfully grow

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G2 Ecosystems and biomes

• G.2.9 Distinguish between biome and biosphere.
• Biome Communities on earth that contain similar
  plant and animal inhabitants
• Biosphere part of Earth that can contain life

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G2 Ecosystems and Biomes

• G.2.11 Outline the characteristics (temperature,
  moisture, vegetation) of six major biomes.
• Desert
• Grassland
• Shrubland
• Temperate deciduous forest
• Tropical rainforest
• Tundra

Build a Biome!
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G1 Community Ecology

• G.1.3 Describe one method of random sampling,
  based on quadrat methods, that is used to compare
  the population size of two plant or two animal
  species.

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• Mark off a large 10 x 10 meter grid area
• Toss a 1 x 1 meter square into the grid area
  randomly
• Identify and count all the larger plant species
  first
• Smaller plant species, like grass, divide your
  square into
• several smaller 10 x 10 cm squares. Count the
  number of
• individual plants in several of those smaller
  squares, average,
• and multiply by 100 to get an estimate.
• 5) Toss the 1 x 1 m square to obtain more data.
  

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G3 Impacts of humans on ecosystems

• G.3.1 Calculate the Simpson diversity index for
  two communities.
• N total number of individual organisms (all
  species combined)
• n number of individuals of a particular species

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G3 Impacts of humans on ecosystems

• G.3.2 Analyse the biodiversity of the two local
  communities using the Simpson index.
• High Index (closer to one) Higher the
  biodiversity
• This index ranges from zero to one and is
  literally a measure of the probability that two
  organisms taken at random from the sample are
  different species. A number close to zero means
  low diversity and it is likely you will get the
  same species of organism and a number close to
  one means high diversity.

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Internal Assessment

• Quadrat Lab

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5.3 Populations

• 5.3.1
• Outline how population size can be affected by
  natality, immigration, mortality and emigration.
• Natality offspring are produced and added to
  the population
• Mortality individuals die and are lost from the
  population
• Immigration individuals move into the area from
  somewhere else and add to the population
• Emigration individuals move out of the area and
  are lost from the population

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5.3 Populations

• 5.3.2
• Draw a graph showing the sigmoid (S-shaped)
  population growth curve.

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5.3 Populations

• Exponential Phase
• Population increases exponentially because the
  natality rate is higher than the mortality rate.
  This is because there is an abundance of food,
  and disease and predators are rare.

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5.3 Populations

• Transitional Phase
• Difference between natality and mortality rates
  are not as great, but natality is still higher so
  population continues to grow, but at a slower
  rate.
• Food is no longer as abundant due to the increase
  in the population size. May also be increase
  predation and disease.

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5.3 Populations

• Plateau Phase
• Natality and mortality are equal so the
  population size stays constant.
• Limiting Factors
• shortage of food or other resources
• increase in predators
• more diseases or parasites
• If a population is limited, then it has reached
  its carrying capacity

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5.3 Populations

• Define carrying capacity.
• The maximum population size that can be supported
  by the environment

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5.3 Populations

• In a random sample, every individual in a
  population has an equal chance of being selected.
• Describe one technique used to estimate the
  population size of an animal species based on a
  capture-mark-release-recapture method. (2)
• Various mark and recapture methods exist.
• Knowledge of the Lincoln index (which involves
  one mark, release and recapture cycle) is
  required.

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5.3 Populations

• population size
• where . . .
• n1 number of individuals initially caught,
  marked and released
• n2 total number of individuals caught in the
  second sample
• n3 number of marked individuals in the second
  sample

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5.3 Populations

• IA Mark and Recapture

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5.2 Greenhouse effect

• 5.2.1
• Draw the carbon cycle to show the processes
  involved.
• The details of the carbon cycle should include
  the interaction of living organisms and the
  biosphere through the processes of
  photosynthesis, respiration, fossilization and
  combustion. Recall of specific quantitative data
  is not required.

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5.2 Greenhouse Effect

• 5.2.2
• Analyze the changes in concentration of
  atmospheric carbon dioxide using historical
  records.
• Whats happening to carbon dioxide levels?

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5.2 Greenhouse effect

• Explain the relationship between rises in
  concentrations of atmospheric carbon dioxide,
  methane and oxides of nitrogen and the enhanced
  greenhouse effect.

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Greenhouse Effect

• Causes
• Light from the sun has short wavelengths and can
  pass through most of the atmosphere.
• This sunlight warms the earth which in turn emits
  long wave radiation.
• This long wave radiation is bounced back by the
  greenhouse gases, such as carbon dioxide,
  methane, water vapour, and sulphur dioxide

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5.2 The greenhouse effect

• 5.2.6 Outline the consequences of a global
  temperature rise on artic ecosystems.
• Loss of ice habitat
• Increased success of pests

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G3 Impacts of humans of ecosystems

• Ozone layer absorbs UV radiation
• CFCs are causing a hole in the ozone layer
• Excessive UV radiation can cause
• Skin cancer
• Vital bacteria would die

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G3 Impacts of humans on ecosystems

• G.3.4/5 List 3 examples of introduced/alien
  species and discuss the impact.

• Purple Loosestrife
• spread alarmingly fast,
• removed from their natural controlling agents.
• dramatic disruption in water
• flow in rivers and canals,
• - Native food and cover plant species, notably
  the cattails, are crowded out.

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G3 Impacts of humans on ecosystems

• Zebra mussels were first detected in the Great
  Lakes in 1988 and have caused widespread damage
  in the ecosystem.
• Zebra Mussels are edible, but most experts advise
  against eating any found in areas of pollution
  concern since zebra mussels accumulate
  contaminants and toxins from the water that they
  filter.

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G3 Impacts of humans on ecosystems

• - Round Goby
• - Survives well in degraded environmental
  conditions
• Competitive advantage compared to native species.
  
• Heavy feeding on invasive mussels
• (zebra and quagga) results in greater
  biomagnification
• - No predators due to defensive mechanism

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Define biomagnification At each trophic level,
toxic substances (Hg, pesticides, TCDD, etc.)
become more concentrated
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G3 Impacts of humans on ecosystems

• How can we keep invasive species in check via a
  biological mechanism?
• Decide on a local area that is currently being
  impacted negatively by an invasive species.
• Find out what that negative impact is and which
  of the invasive species is causing it.
• Research a BIOLOGICAL means of controlling that
  species in order to stop the negative impact.
• Put together a proposal illustrating your method
  of restoring the ecosystem.