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Option G: Ecology and Conservation


Title: Option G: Ecology and Conservation Author: TVUSD Last modified by: BLS User Created Date: 1/5/2010 6:40:29 PM Document presentation format – PowerPoint PPT presentation

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Title: Option G: Ecology and Conservation

Option G Ecology and Conservation
  • Outline the factors that affect the distribution
    of plant species
  • Temperature
  • Water
  • Light
  • soil pH
  • salinity
  • mineral nutrients (NPK etc.)

Prefers acidic soil
Salt tolerant
  • Explain the factors that affect the distribution
    of animal species
  • Temperature
  • water
  • breeding sites
  • food supply
  • territory

  • Describe one method of random sampling, based on
    quadrat methods, that is used to compare
    population size of two plant or two animal
  • 1.Mark out gridlines along 2 edges of the area to
    be sampled.
  • 2. Generate two random numbers and place the
    corner of the quadrat at the coordinates
  • 3. Count the individuals of interest in the
  • 4. Repeat steps 2 and 3 as much as possible.
  • 5. Measure the total size of the area occupied
    by the population in square meters
  • 6. Calculate the estimated population size for
    the area
  • Pop. Size mean number per quadrat x total area
  • area of each quadrat
  • Compare your count to a count from another area
    of interest.

  • Outline the use of a transect to correlate the
    distribution of plant or animal species with an
    abiotic variable.
  • Transect more systematic
  • Done along a line (not random)
  • How would this be done?

A trapped weasel
  • Describe one technique used to estimate the
    population size of an animal species based on a
    capture-markreleaserecapture method.
  • Knowledge of the Lincoln index (which involves
  • markreleaserecapture cycle) is required, as
  • Population size (n1 x n2) /n3
  • where n1 number of individuals initially
    caught,marked and released,
  • n2 total number of individuals caught in the
    second sample, and
  • n3 number of marked individuals in the second

The Niche
  • Ecological niche all the characteristics, biotic
    and abiotic, specific to a species. It includes
  • spatial habitat
  • feeding activities
  • Interactions with other organisms.
  • Distinguish Fundamental vs. realized niches
  • fundamental/theoretical the niche a population
    is theoretically capable of occupying under ideal
  • realized the niche population actually occupies

Ex Barnacle sp. on the coast of Scotland
The Competitive Exclusion Principle
  • 2 species with similar needs for the same
    limiting resources cannot coexist in the same
  • Thus, 2 species cannot coexist in a community if
    their niches are identical
  • Why?
  • example experiment?

  • Definition
  • Symbiosis is a close ecological relationship
    between the individuals of two (or more)
    different species.   Sometimes a symbiotic
    relationship benefits both species, sometimes one
    species benefits at the other's expense, and in
    other cases neither species benefits.

Types of Symbiosis
  • Ecologists use a different term for each type of
    symbiotic relationship
  • Mutualism   --   both species benefit
  • Commensalism   --   one species benefits, the
    other is unaffected
  • Parasitism   --   one species benefits, the other
    is harmed
  • Competition   --   neither species benefits
  • Neutralism   --   both species are unaffected

  • Biomass the dry weight of organic matter in
    organisms of an ecosystem.
  • Describe one method for the measurement of
    biomass of different trophic levels in an
  • Get dry weight of organism
  • Estimation necessary sometimes
  • Can be destructive (ethical issues?)

Felling a 30-year old agroforestry black walnut
to measure its biomass and allometrics.
Matter and Energy Flow, I
  • Primary production (amount of light energy
    converted to chemical energy by autotrophs)
  • Gross production(GP) the total amount of
    organic material produced by producers in an
  • Net production (NP) gross production minus the
    material expended by producers in respiration.
    (stored energy available to consumers)
  • R respiration
  • NP GP - R

Energy Flow, II
  • Ecological efficiency of E transferred from
    one trophic level to the next (5-20) (average
  • Pyramid of productivity shows multiplicative
    loss of energy in trophic levels
  • Biomass pyramid trophic representation of
    biomass in ecosystems
  • Pyramid of numbers trophic representation of the
    number of organisms in an ecosystem

Check yourself 1
  • Discuss the difficulties of classifying organisms
    into trophic levels.
  • Explain the small biomass and low numbers of
    organisms in higher trophic levels.
  • Construct a pyramid of energy given appropriate
  • Describe an example for each of the symbiotic
    relationships described.

  • Ecological succession transition in species
    composition over time
  • Primary begun in lifeless area no soil,
    (perhaps volcanic activity or retreating glacier)
    Lichens pioneer species
  • Secondary an existing community has been cleared
    by some disturbance that leaves the soil intact
  • Climax community

Check yourself
  • Distinguish between primary and secondary
    succession, using an example of each.
  • Outline the changes in species diversity and
    production during primary succession.
  • Explain the effects of living organisms on the
    abiotic environment, with reference to the
    changes occurring during primary succession.

  • I. Biome a large group of ecosystems that share
    the same type of climax community
  • Type of biome determined largely by
  • Precipitation
  • temperature

  • 2. Major terrestrial biomes
  • a. tundratreeless (or very small trees may be
    present), permafrost, low nutrient soil, low
    precipitation. slow decay. Around poles.
  • b. taiganorthern coniferous forestacidic/nutrie
    nt poor topsoil, long harsh winters, short
    summers. Cold but no permafrost.
  • c. desertlow precipitation, warm to very hot
    days and cold nights, very few plants (some store
    water, some grow quickly with rain.)
  • d. Grasslandfew trees, low rainfall, warm to
    hot summers, cold winters. Dominated by grasses
    and plants tolerant of grazing. experience a dry
    season, unpredictable precipitation, fertile
  • e. temperate deciduous foresttrees lose leaves,
    warm summers, cool winters. Moderate rainfall.
  • f. tropical rain forest hot in all seasons,soil
    is nutrient poor. Rains frequently/ high
    precipitation. Highest biodiversity of
    terrestrial biomes. Canopy prevents understory
    plant growth.

Check Yourself 2
  1. Explain how rainfall and temperature affect the
    distribution of biomes.
  2. Outline the characteristics of six major biomes
    include in your description the major flora and
    fauna or provide a picture.

Simpsons Diversity Index
  • Simpson's Diversity Index is a measure of
    diversity. In ecology, it is often used to
    quantify the biodiversity of a habitat. It takes
    into account the number of species present, as
    well as the abundance of each species.

  • Calculate the Simpson diversity index for two
    local communities.
  • Analyse the biodiversity of the two local
    communities using the Simpson index.
  • The Simpson diversity index is a measure of
    species diversity
  • D is the diversity index,
  • N is the total number of organisms of all species
  • n is the number of individuals of a particular
  • A high value of D suggests a stable and ancient
    ecosystem and a low D value could suggest
    pollution, recent succession or agricultural
  • The index is determined by counting organisms on
    randomly chosen parts of an area. Monitoring over
    time shows changes in an ecosystem.

Example N 42 Get n for each species and plug
Species Number Found
Mayfly larva 8
Dragonfly larva 5
Caddisfly larva 4
Stonefly larva 4
Pond skater 3
Water louse 2
Water mite 1
Flatworm (Dendocoelum sp.) 4
Flatworm (Dugesia sp.) 3
Leach 1
Annelid worm 2
Snail 4
Pearl mussel 1
D ___42 (42-1)______ 8 (8-1) 5 (5-1) 4
(4-1) etc D ___42 (42-1)______ 140
Practice problem Calculate the Simpson
diversity index for the following community
Species Number Found
Mayfly larva 8
Dragonfly larva 5
Caddisfly larva 4
Stonefly larva 4
Pond skater 3
Water louse 2
Water mite 1
Check Yourself 3
  • Discuss reasons for the conservation of
    biodiversity using rainforests as an example.

Rainforest Example
  • Economic reasons
  • Ecotourism
  • New products/drugs
  • Ecological reasons
  • Ecological relationships/symbiosis
  • Erosion
  • Carbon and oxygen cycles
  • Climate effects
  • Ethical reasons
  • Intrinsic value of living things
  • Cultural importance of native species
  • Effects on future generations
  • Medicines (potentially)
  • Aesthetic reasons

  • II. Importance of Biodiversity
  • A. Beauty
  • B. ecological relationships between organisms
  • C. Importance to peoplemedicines
    (Taxol-Pacific Yew), mold- penicillin, rosy
    periwinkledrugs for Hodgkins disease (lymphatic
    cancer) and leukemia, Willow barkaspirin,
    cinchona tree barkquinine) Other uses?

List three examples of the introduction of alien
species that have had significant impacts on
ecosystems.Discuss the impacts of alien species
on ecosystems.
  • 3 examples of alien species
  • Brown tree snake in Guam (see biological
    invaders http//www.pbs.org/cgi-registry/2wgbh/evo
  • Cane toad in Australia (originally introduced to
    control sugar cane pests) http//video.nationalgeo
  • Fennel and European grasses in CA (more info on
    fennel http//www.cal-ipc.org/ip/management/ipcw/

Some California Native Plants
  • Island Buckwheat, Channel Islands, California
  • Dudleya, Channel Islands, California

Indian Paintbrush
  • Lemonade Berry, Channel Islands, California

Fennel the alien
  • Removing invasive fennel

Outline one example of biological control of
invasive species.
  • http//www.sciencedaily.com/releases/2008/05/08050

Check Yourself 4
  1. Find one invasive plant species and one invasive
    animal species in Oregon. What are the
    consequences of this invasion?

  • Define biomagnification.
  • Biomagnification process by which chemical
    substances become more concentrated at each
    higher trophic level.
  • Explain the cause and consequences of
    biomagnification, using a named example.
  • Cause
  • Consequences
  • Named examples Mercury in fish, DDT and
    pelicans, eagles, Island foxes.

  • Outline the effect of chlorofluorocarbons (CFCs)
    on the ozone layer.
  • ozone in the stratosphere absorbs UV radiation.
  • Chlorine breaks away from CFC molecules (caused
    by UV light)
  • Chlorine (highly reactive) reacts with ozone
    (breaks it down to make oxygen)
  • One chlorine can break down hundreds of thousands
    of ozone molecules.
  • Animation http//www.bom.gov.au/lam/Students_Teach

  • Outline the effects of UV radiation on living
    tissues and biological productivity.
  • a) Increases the mutation rates in DNA.
  • b) Causes severe sunburns and damage to eyes
  • c) Increases incidence of cancers (melanoma).
  • d) Reduces rate of photosynthesis in plants
    (lowers energy output of producers!).

  • Explain the use of biotic indices and indicator
    species in monitoring environmental change.
  • Indicator species
  • highly sensitive to environmental changes
  • their populations increase or decrease
    significantly depending on changes in the
  • Ex. Frogs and pollution http//environment.newscie
  • Ex. sludge worms-- indicate low oxygen
    concentration in water.
  • Biotic index Scale for showing the quality of an
    environment by indicating the types of organisms
    present in it (e.g. how clean a river is).
    (Source PHC) Ex. http//www.pisces-aqua.co.uk/aqu

Check yourself 5
  1. Explain the use of biotic indices and indicator
    species in monitoring environmental change.

  • Outline the biogeographical features of nature
    reserves that promote the conservation of
  • Large size (why?)
  • Avoid habitat fragmentation and edge effect (ex.
    Cowbirds parasitize nests on forest edges)
  • Habitat corridors to connect fragmented habitats.
  • Inclusion of a variety of abiotic factors also
    promotes diversity. (Why? Discuss)

  • Discuss the role of active management techniques
    in conservation.
  • If human disturbance has degraded a habitat,
    active management may be necessary. (It wont
    always return to its natural state on its own)
  • Example removing goats, pigs, golden eagles, and
    invasive plants on the Channel Islands

  • Discuss the advantages of in situ conservation of
    endangered species (terrestrial and aquatic
    nature reserves).
  • In situ Nature reserves
  • Advantages
  • Species are adapted to habitat
  • Genetic diversity
  • Natural behavior patterns
  • Interaction of species in ecosystem

Wolong Nature Reserve (China)
Jaguar Preserve (Belize)
  • Outline the use of ex situ conservation measures,
    including captive breeding of animals, botanic
    gardens and seed banks.
  • Captive breeding
  • Botanic gardens
  • Seed banks (most seeds kept cold -10?-20 C can
    last over 100 years)

Check Yourself 6
  • Outline the factors that contributed to the
    extinction of one named animal species.
  • Pick a species that you will remember!
  • Outline the factors that contributed to its
    extinction in your notes.
  • Include a picture of your animal species if

  • Reproductive patterns
  • r strategists--rapid life histories, rapid
    reproduction of many small offspring
  • in unpredictable unstable environments
  • k strategistslarge, reproduce and mature
    slowly, long-lived, often care for young
  • In stable environments

Check Yourself 7
  1. Distinguish between r-strategies and
  2. Discuss the environmental conditions that favour
    either r-strategies or K-strategies.

  • Describe the methods used to estimate the size of
    commercial fish stocks.
  • Use fish catch data to get a count and age
    distribution. Use this to estimate in conjunction
    with spawning rates and survivorship curves
  • Capture-mark-release-recapture
  • Works in lakes, but not in oceans
  • Echo sounders in conjunction with trawling to
    determine which species have been echolocated.
  • None of these methods estimate with much
    certainty leading to disagreements.

  • Outline the concept of maximum sustainable yield
    in the conservation of fish stocks.
  • Maximum sustainable yield Largest amount of
    fish that can be harvested without a decline in
    fish stocks.

  • Discuss international measures that would promote
    the conservation of fish.
  • Monitoring stocks and repro rates
  • Quotas for species with low stocks
  • Closed seasons (esp. breeding season)
  • Exclusion zones with no fishing allowed
  • Moratoria on catching endangered species
  • Minimum net sizes (so baby fish arent caught)
  • Banning of drift nets

A lone bat ray is  tangled in the mesh of a
drift net. Not considered for human consumption,
this ray will likely be thrown overboard once the
net is hauled in. (Ocean.com)
Check Yourself 8
  1. Which of these measures do you think would be
    most effective? Why?
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