Ecosystems and material cycles

• whats an ecosystem ?

  a stable relationship between organisms, habitat and non living factors
• whats a community ?

  all the different organisms living and interacting within an ecosystem
• whats a habitat ?

  the place where an organism lives
• whats a food web ?

  diagram of linked food chains showing community feeding relationships
• whats does interdependent mean ?

  when organisms need eachother for resources such as food or shelter
• what does population mean ?

  the number of individuals of a particular species within an area
• what does distribution mean ?

  the places where a certain organism is found within a habitat
• whats a quadrat ?

  a frame of known area (e.g. 0.25m (squared) used to sample for populations
• whats a belt transect ?

  a line through a habitat along which samples are taken to find patterns
• whats a sample ?

  a small representative portion of an area or population
• what are abiotic factors ?

  non living conditions that influence where plants or animals live (e.g. light)
• what is biodiversity ?

  the amount of variety of different species within an ecosystem
• whats a predator-prey cycle ?

  a cyclic variation in populations of interdependent predators and prey
• whats mutualism ?

  a relationship between two different species that benefits both
• whats parasitism ?

  a relationship where an organism feeds upon a living host organism
• whats an indigenous species ?

  species that have evolved and adapted to a habitat over a long time
• what does non-indigenous mean ?

  species introduced to an area where they had not existed before
• whats conservation ?

  protection of an area or a species to prevent ecosystem damage
• whats an endangered species ?

  a species at risk of local or total extinction
• whats reforestation ?

  replanting new forests where older forests have been cut down
• whats the carbon cycle ?

  processes that move carbon between the atmosphere, organisms and the earth, and back to the atmosphere again
• whats a decomposer ?

  an organism that feeds on dead material causing decay
• whats the nitrogen cycle ?

  processes that move nitrogen between the atmosphere, organisms and the earth, and back to the atmosphere again
• what does nitrogen-fixing mean ?

  process by which lightning or soil bacteria turn nitrogen into nitrates
• what does eutrophication mean ?

  the addition to an ecosystem of more nutrients than it normally has
• whats crop rotation ?

  where different crops are planted in a cycle that returns nutrient to soil
• whats the water cycle ?

  movement of water between the sea, atmosphere, rivers and organisms
• whats desalination ?

  process that separates fresh potable water from salty sea water
• what are adaptations ?

  features or traits which make a species become better suited to its environment. These emerge through evolution by natural selection
• what is photosynthesis ?

  Process used by plants to convert light energy into chemical energy that can later be released to fuel the organisms' activities
• whats diffusion ?

  The net movement of particles from an area of high concentration to an area of low concentration until evenly spread out
• whats surface area : volume ratio ?

  the surface area to volume ratio (SA/V) also called the surface to volume ratio is the amount of surface area per unit volume of an object
• whats the concentration gradient ?

  the magnitude of difference in concentration between to neighboring area
• whats a food chain ?

  a diagram showing the flow of energy as materials are being passed on to one organism to another
• whats a producer ?

  an organism that makes its own nutrients (food) using energy from sunlight by photosynthesis
• whats a pyramid of biomass ?

  a diagram showing the biomass at each trophic level, rather than the population
• whats a sankey diagram ?

  a diagram that shows the flow and wastage of energy from a system using arrows. The thickness of the arrows is proportional to energy
• what does biotic mean ?

  the living components of an ecosystem
• what does abiotic mean ?

  the non living components of an ecosystem
• what does food security mean ?

  having access to enough safe and healthy food at all times