Fieldwork (required practical): Ecology: Biology: GCSE (9:1)

• Habitat


  The specific area or environment where an organism lives

  
• Ecosystem


  The interaction of a community of living organisms with the non-living parts of the environment

  
• Biotic and abiotic factors

  Biotic factors are a result of living things in an environment such as food availability, abiotic factors are a result of non-living things in an environment such as temperature

  
• Distribution of a species


  The range or spread of the individuals of a species in an area

  
• Factors affecting the distribution of a species

  Typically abiotic factors such as light intensity or soil mineral content but can also include biotic factors such as competition

  
• Abundance of a species

  The amount of individuals of one species found in an area at the same time

  
• Sampling techniques


  A range of scientific techniques used by ecologists to measure the distribution and abundance of different species

  
• Quadrat


  A square frame that is thrown or placed to count individuals of a specific species, typically used to estimate a population size in an area

  
• Transect

  A line or tape measure that covers the length of a specific area and can be used as a reference to measure the distribution of a species at regular intervals

  
• Belt transect

  A combination of quadrats and line transects, a quadrat is placed at specific intervals of the transect and can be used to measure the distribution and abundance of a species

  
• Tape measures


  Can be used to work out the area of a field or can act as a line transect to measure species distribution

  
• Mean average


  The total sum of the data values divided by the number of times the data was recorded

  
• Population size or density


  The estimated size of the population of one species found in the same area at the same time

  
• Common species


  An easily observable and frequent species such as a daisy or dandelion

  
• Random sampling


  Sampling techniques should be random to avoid bias and ensure an investigation is fair
• Random number generator


  A computer can randomly assign coordinates for quadrat placement or numbers can be drawn at random from a bag to avoid bias

  
• Valid results

  To ensure results are valid the number of quadrats placed or thrown can be increased or the investigation could be repeated
• Total population size equation

  (Total field area/area sampled) x total number of individuals of a specific species counted
• Area sampled calculation

  Area of one quadrat multiplied by the number of quadrats used in an investigation
• Expected results for transect investigation

  A factor such as light intensity can affect the distribution of a plant species, a shaded area might have few individuals and a more exposed area might have many individuals

  
• Uncontrollable variables


  Certain additional factors that are difficult to account for can affect the distribution of a species, for example beneficial moisture may be more prevalent in shaded areas when investigating light intensity
• Kite diagram


  A diagram used to visualise the abundance and distribution of different species, using belt transect data