topic b7- ecology

• organisms compete for resources to survive
• plants need

  • light
  • water
  • space
• animals need

  • space
  • food
  • water
  • mates
• habitat

  the place an organism lives
• population

  all organisms of a species in a habitat
• community

  populations of different species in a habitat
• abiotic factors

  non-living factors of environment
• biotic factors

  living factors of environment
• ecosystem

  interaction of a community of biotic organisms with abiotic features
• biotic factors

  • new predators
  • prey
  • competition for resources
  • new diseases
• abiotic factors

  • light intensity
  • temperature
  • carbon dioxide/ oxygen
  • moisture level
• behavioural adaptations

  • the way an organism behaves
  • examples
  • birds migrate to warmer climates in winter
• structural adaptations

  • features of an organisms body structure
  • examples
  • whales have a layer of blubber for warmth
  • camels have a large SA:volume to help heat escape
• functional adaptations

  • functions within an organism
  • examples
  • bears hibernate to slow metabolism
  • desert animals produce less sweat to keep heat
• food chains

  • producer
  • primary consumer
  • secondary consumer
  • tertiary consumer
• food chains- biomass decrease further down the food chain

  
• predator-prey cycle

  
• the water cycle

  
• the water cycle

  • precipitation
  • transpiration
  • evaporation
  • condensation
• the carbon cycle

  
• the carbon cycle

  The carbon cycle moves carbon between the air, plants, animals, and the ground through photosynthesis, respiration, decay, and burning.
• biodiversity

  the variety of different species of organisms on earth, or within an ecosystem
• high biodiversity is important

  it ensures ecosystems are stable
• human actions affecting biodiversity

  • waste production
  • deforestation
  • global warming
• using quadrats

  • quadrats (square frames) sample organisms in a given area

  steps

  1. place randomly, count organisms
  2. repeat for accuracy
  3. calculate mean organisms per m^2
  4. multiply by total area for population estimate
• estimating population size

  mean per m^2 x total area = estimated population
• using transects

  • transects study species distribution along a line

  steps

  1. use a tape measure as a line
  2. count organisms touching the line or use quadrats at intervals
  3. calculate percentage cover for plants

  (squares covered / 100 ) x 100
• biodiversity

  variety of species, crucial for ecosystem stability
• threats to biodiversity

  • human activity- pollution, deforestation
  • waste- water, chemicals, sewage, land, pesticides, landfill, air, acid rain
• global warming

  an increase of the earths atmosphere caused by greenhouse gases
• greenhouse gases

  co2 and methane
• effects of global warming

  • rising sea levels- flooding
  • changing species distribution and migration
  • biodiversity loss
• deforestation

  the cutting down of trees done for farming and biofuels
• impacts of deforestation

  • less co2 absorbed- less photosynthesis
  • more co2 released- burning, decomposition
  • habitat loss- biodiversity decline
• peat bogs

  store carbon but release co2 when drained or burned
• conservation strategies for maintaining ecosystems and biodiversity

  • breeding programmes- protect species
  • habitat protection- reserves, reforestation
  • field margins and hedgerows- farmland biodiversity
  • regulations- reduce deforestation and emissions
  • recycling- reduce waste and landfill
• challenges to conservation strategies for maintaining ecosystems and biodiversity

  • cost
  • jobs
  • food security
  • land demand