ecosystems

• what is ecology?

  study of the relationships between organisms and their environments
• what is an ecosystem?

  • made up of a community of living organisms interacting with one another AND with their physical environment
  • interaction between biotic and abiotic factors
• true or false? ecosystems don't vary in size

  FALSE- they can vary very dramatically in size
• what are the boundaries of a particular ecosystem defined by?

  the boundaries are defined by any person or people carrying out studies in that specific area eg- a rock pool
• what does it mean when ecosystems are referred to as dynamic?

  they are constantly changing
• what two factors affect ecosystems and cause them to change constantly?

  • abiotic- interactions between organisms that are non living
  • biotic- interactions between organisms that are living
• state examples of common abiotic factors within an ecosystem

  • light- plants require for photosynthesis
  • temperature- enzymes controlling metabolic reactions- plants and ectotherms develop more rapidly in warmer temperatures, endotherms are less affected by temperature, they control their internal body temperature
  • water availability- a lack leads to water stress- plants wilt as cells stop being turgid, photosynthesis affected
  • oxygen availability- water too warm= [oxygen] drop, aquatic animals suffocate, waterlogged soil means no oxygen, water fills up air spaces
  • soil- clay/loam/sandy soil
• state the three different types of soil and the organisms that can survive in them

  • clay- fine particles, easily waterlogged and forms clumps when wet
  • loam- different sized particles, retains water but doesn't become waterlogged
  • sandy- coarse- well separated particles that allow free draining, sandy soil doesn't retain water and is eroded easily