Environmental Science: Unit One - Living Environment

• Biodiversity


  The variety of species and ecosystems on Earth and the ecological processes of which they are part
• Types of biodiversity


  • Ecosystem diversity
  • Species diversity
  • Genetic diversity
• Species diversity


  A measure of the number of different species present in a given area, rather than the abundance of each species
• Species richness


  The number of species present in a sample or an area
• Relative abundance


  How common or rare a species is relative to other species in a defined area or community, expressed as a percentage of the total number of organisms
• Ecosystem diversity


  The variation in habitats, living communities, and ecological processes in the living world
• Genetic diversity


  The variety of genetic characteristics involved in the genetic makeup of a species
• Qualitative data


  Descriptive data used to prepare a species list
• Quantitative data


  Numerical data that can be counted or measured, providing information on numbers and densities
• Quantitative data allows us to assess

  • Density
  • Percentage cover
  • Frequency
  • Distribution
  • Relative abundance
• The data obtained can be made more reliable by repeating the experiment several times and taking an average
• The data obtained can be made more valid by identifying organisms or values using a second technique
• Experimental technique can be made more valid by controlling all key variables
• Randomisation of sampling is important as it eliminates bias
• Types of random sampling

  • Simple
  • Systematic
  • Stratified
• Biotic index


  A scale showing the quality of an environment based on the types of organisms which inhabit it
• Biotic/biodiversity indices


  • Simpson's Biodiversity Index
  • Trent Biotic Index
  • Lincoln Index
• Simpson's Biodiversity Index


  A measure of diversity which takes into account the number of species present, plus the relative abundance of each species
• Lincoln Index


  A method of estimating population sizes of individual animal species using capture-mark-recapture

  
• Trent Biotic Index


  Uses freshwater invertebrates to compare water quality at different points in a stream or river
• Invasive vs non-invasive sampling techniques

  • Invasive: ensures each organism is only counted once, caught organisms are quicker and easier to identify
  • Non-invasive: allows organisms to be studied in their natural environment without altering behaviour, less likely to cause habitat damage
• Types of transects


  • Line transects
  • Belt transects
  • Point transects
• Aquatic abiotic factors and how to measure them

  • Temperature: temperature probe/thermometer
  • Water flow rate: pygmy meter
  • Dissolved oxygen concentration: dissolved oxygen meter
  • Biological oxygen demand: BOD biosensor
  • pH: pH probe
  • Salinity: mass of water sample, evaporate and reweigh
  • Tidal effects: acoustic sounding tube and sensor