B4 Biology - Ecology in the local environment

Collecting organisms
1. Nets
  1. Useful for collecting flying insects
2. Pooters
  1. Small jar that collects insects
    1. 2 tubes
      1. 1 in your mouth
        You can apply suction
      2. 1 over the insect
        Sucked into jar
3. Pitfall traps
  1. Used to sample small invertebrates
    1. A container buried in the ground with it's top at ground level
      1. Covered with wood with a slight gap so insects can climb in
4. Quadrats
  1. Square made of wire
Counting population sizes
1. Sample area - Quadrats
  1. When using a quadrat...
    1. It should be placed randomly
      1. So that a representative sample is taken
    2. The validity and reproducibility of the results increases
      1. as the results from more quadrats are analysed
2. Capture-recapture
  1. Some animals are trapped
    1. They are then marked in a harmless way then released
      1. Traps are then used again
        The number of marked and unmarked animals are recorded
        Population size then estimated using...
        (Number in 1st sample x number in 2nd sample) / number in 2nd sample previously marked
  2. Higher tier
    1. When using capture-recapture, you must make assumptions including...
      1. There is no death, immigration or emigration
      2. The sampling methods used are identical
      3. The marking has not affected the survival rate of the animal
Using keys
1. Used to identify a species
2. Can be branching or a series of paired statements with yes/no answers
3. Based on physical characteristics
  1. Example
    1. Statement Answer
    2. 1.Does the animal have 4 legs? Yes - go to statement 2
    3. No - go to statement 4
    4. 2. Does the animal have a curly tail? Yes - pig
    5. No - go to statement 3
    6. 3. Does the animal have a hoof divided into 2 parts? Yes - Cow
    7. No - horse
    8. 4. Does the animal have webbed feet? Yes - Duck
    9. No - Human
Ecosystems
1. Environment
  1. All the conditions that surround a living organism
2. Habitat
  1. The place where an organism lives
3. Population
  1. All the members of a single species that live in a habitat
4. Community
  1. All the populations of different organisms that live together in a habitat
5. Ecosystem
  1. A community and the habitat in which it lives
    1. Some ecosystems are natural, others are artificial
      1. Example
        Natural Artificial
        Native woodland
        Lake
        Forestry plantation
        Fish farm
6. Biodiversity
  1. Is the variety of different species living in a habitat
    1. The greater the number of species in a habitat, the greater its biodiversity
    2. Natural ecosystems are likely to have a larger biodiversity than artificial ones
      1. Example - a lake may contain many species of fish but a fish farm may only have 1 species
Transects and kite diagrams
1. Transects
  1. A transect is a line across a habitat or part of a habitat
    1. Can be as simple as a string or rope placed in a line on the ground
      1. The number of organisms of each species can be observed and recorded at regular intervals along the transect
2. Kite diagrams
  1. A kite diagram is a chart that shows the number of animals (or % cover for plants) against distance along a transect
  2. The distribution of organisms in a habitat is affected by...
    1. The presence of other living organisms like herbivores or predators that might eat them
    2. Abiotic factors (physical factors) such as availability or light or water
3. Zonation (Higher tier)
  1. A gradual change in the distribution of species across a habitat
    1. It can happen because of a gradual change in an abiotic factor

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B4 Biology - Ecology in the local environment

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	Created by libby.kew about 11 years ago