ecology

• Ecology


  The study of the interactions between organisms and their environment
• Biosphere


  The part of the planet where life can exist
• Ecosystem


  A community of organisms that interact with their environment
• Ecosystems


  • Grassland
  • Pond
  • Meadow
  • Hedgerow
  • Rockpool
• Organisms are adapted to the specific environment of the ecosystem
• Community


  All the different organisms in the area in the ecosystem
• Population


  All the members of the same species in an area
• Habitat


  The place where an organism lives
• Feeding relationships in an ecosystem

  1. Flow or transfer of energy from one organism to the next

  2. Photosynthesis traps and converts sun's energy into chemical energy

  3. Plant eaten by animal

  4. Animal eaten by another animal

  5. Most energy lost as heat
• Trophic level


  The feeding position in a food chain
• Food chain starts with producer, then primary consumer, secondary consumer etc.
• Food web


  Made up of many interconnected food chains
• Types of organisms


  • Herbivore (eats plants only)
  • Carnivore (eats animals only)
  • Omnivore (eats both plants and animals)
• Niche


  The role an organism plays
• No two species can occupy the same niche due to competition
• Pyramid of numbers


  Represents the number of organisms at each trophic level
• Pyramid of numbers always starts with producer at the base
• Limitations of pyramids of numbers: don't account for organism size, difficult to draw to scale, can be inverted
• Environmental factors affecting organisms

  • Abiotic (non-living)
  • Biotic (living)
• Abiotic factors


  • Climatic
  • Edaphic (soil-related)
  • Topographic
• Biotic factors


  • Presence of humans
  • Dispersal
  • Predation
  • Competition
  • Parasitism
  • Pollination
• C.P.P.S.


  Competition, Predation, Parasitism, Symbiosis - factors controlling populations
• Intraspecific competition


  Competition between members of the same species
• Interspecific competition


  Competition between members of different species
• Contest competition


  One species/organism gets all the resource
• Predation


  Catching, killing and eating another organism
• Parasitism


  One organism lives on or in another, feeding on it and causing harm
• Types of parasitism


  • Ectoparasite (lives outside host)
  • Endoparasite (lives inside host)
• Symbiosis


  Relationship between different species where at least one benefits
• Types of symbiosis


  • Mutualism (both benefit)
  • Commensalism (one benefits, other not harmed)
• Introduction of non-native/exotic species can have unintended consequences
• Biological control


  Introducing one organism to control numbers of another
• Factors affecting aquatic habitats

  • Light penetration
  • Current action
  • Wave action
  • Salt concentration
  • Oxygen concentration
• Factors affecting human population

  • War
  • Famine
  • Disease
  • Natural disasters
  • Contraception
• Conservation


  Management of the environment to maintain biodiversity and prevent species extinction
• Conservation practices


  • Fishing quotas
  • Net size regulation
• Pollution


  Any harmful addition to the environment
• Agricultural pollution


  • Slurry (rich in nutrients, causes algal bloom and eutrophication)
• Preventing agricultural pollution


  1. Storing slurry in tanks

  2. Spreading slurry only in dry weather
• Waste management methods


  • Landfill
  • Incineration