Ecology

• Habitat 


  Place that an organism lives
• Population

  All the organisms of a particular species that live in that habitat
• Community

  All populations of different species in that habitat
• Competition

  Animals compete over space, food, water, mates

  plants compete for light, space, water and minerals
• Interdependence 


  All species depend on other species in some way

  this is shown by food webs
• Biotic factors

  Any living factor that affects another organism or ecosystem

  e.g competition for resources ; amount of disease ; availability of food
• Abiotic factors

  Any non living part of environment that can affect organisms

  e.g light intensity ; carbon dioxide conc ; moisture ; wind ; ph and minerals of soil
• Adaptations 


  Any organism to survive adapts to its environment

  the types are structural ; behavioural and functional
• Structural 


  Physical features like shape and colour

  e.g seals & walrus = round/store fat = low volume to SA = conserve heat
• Behavioural


  The way an organism behaves or acts

  e.g elephants = flaps ears & spray water on themselves = cool down in hot weather

  or birds = migration = avoid cold and lack of food
• Functional 


  Processes inside an organism like metabolism or reproductI’ve system

  e.g desert animals = very little sweat + concentration urine + fat in humps
• Extremophiles 


  Microorganisms (bacteria and archaea) adapted to live in extreme environment like high pressures , temperatures and salt conc

  Even some in space on outside of international space station
• food chains


  Producers — primary consumer— secondary consumer — tertiary consumer
• Sampling methods


  Quadrants - measure abundance

  transects - measure how distribution changes
• Quadrats


  method : place several tape measures to create a large grid

  Use random number generator to pick 10 pairs if coordinates

  place quadrant at each coordinate an count how many dandelions in each quadrats

  calc a mean number per meter squared

  estimate total population using the mean per meter squared and total area
• Transects


  Method : set out a transects line between lake and woodland

  set out quadrats at regular intervals

  abundance is counted by the number of dandelions per quadrat

  Repeat steps 1 to 3 in parallel to get data that’s more representative of area
• water cycle


  -sun provides energy that causes water to evaporate from seas lakes etc (and transpiration)

  -water vapour condenses in the sky as clouds

  -eventually water falls back down due to precipitation as rain

  -water returns back to rivers soil seas etc
• Carbon cycle


  -stored in air, plants, soil, fossil fuels and animals

  -photosynthesis absorbs carbon dioxide, it can then be respired back into atmosphere or consumed by animals then respired

  -when plants and animals die carbon dioxide can be released in decaying by respiration or turned into fossil fuels and burned
• decay


  When dead organic matter is broken down by decomposers (bacteria + fungi) or detritus feeders (worms + wood lice)
• biodiversity


  variety of different species on earth, or within an ecosystem
• Reducing biodiversity 


  Damaging the environment reduces biodiversity through consumer goods e.g phones, clothes, cars etc

  we use natural resources faster than they are replaced e.g black rhino horns = extinction due to poaching

  deforestation = destroy habitats

  waste (individual + collectively)
• Waste in Water


  From sewage, industries and farming run into bodies of water

  causes pollution killing wildlife
• waste on land 


  We bury waste in landfills as well as nuclear waste underground in concrete which can seep out toxins

  toxins kill wildlife and ecosystems
• Waste in air 


  Industrial processes release toxic chemicals + gases

  burning fossil fuel

  can cause acid rain or harm animals directly
• high biodiversity pros


  -drugs come from wild resources origionally

  -increases stability of ecosystem

  -species can have certain roles like pollinators
• Maintaining biodiversity


  Breeding programmes for endangered species - done in captivity then released

  protect habitats for species e.g mangrove or coral reefs

  New laws to reduce impacts e.g field margins for wildlife to grow (hedgerow)

  Set quotas for co2 released by businesses

  recycling + less consumerism
• Protecting biodiversity cons


  Expensive to achieve

  things like farming for large population are needed
• Greenhouse effect


  Earth surrounded by layer of gases by gravity

  Radiation emitted from sun hits earth

  Some is absorbed rest reflects and is absorbed by gas particles

  Energy re-emitted in random directions

  So heat energy stays near earth
• Green house gases


  Methane

  Carbon dioxide

  Water vapour
• Global warming 


  Earth temp fluctuates

  Happens because of greenhouse effect

  Increased as humans produve more methane + CO2

  Causes earth to warm up
• Climate change


  Effect of global warming on the climate
• Climate


  Long term weather patterns
• Effect of global warming

  Droughts hurricans and floods become more common and severe

  Sea level rise as ice caps melt due to hot temp and water expands in heat
• Effect on species

  Need to adapt to new conditions

  Migrate to areas with better conditions

  Or they go extinct / endangered
• Deforestation

  Is the destroying of forests

  For farming cattle, crops (rice) or biofuels or for matterials
• Problem of deforestation

  Less photosynthesis = less carbon absorbed and stored = more global warming

  Burning forest = carbon released into atmosphere = polute + suffocate animals

  Destroys habitats = reduce biodiversity + species become extinct
• Peat bogs

  Areas of land where soil is acidic and water logged so no oxygen or microorganisms for decay
• Peat bogs pros

  As plants die the carbon is stored still as aerobic respiration cant occur = reduce global warming
• Peat bogs cons

  Drained to use for farmland = oxygen can enter so respiration occurs = carbon released in decay

  Burning peat as fuel or use as fertiliser = release carbon

  Destroying them destroys habitats = reduce biodiversity
• Trophic levels


  The different levels of a food chain