Ecology Flashcards
What is an ecosystem?
A system or area where organisms interact with their physical environment
What two things do all ecosystems have?
Biotic factors (Living things) Abiotic factors (non-living things)
What three general groups of things are BIOTIC?
Producers (e.g Photosynthesising plants), Consumers (e.g animals), Decomposers (Breakdown organic matter)
Define ABIOTIC?
A physical environment that affects the growth and survival of living things
What is the variety of species found within an ecosystem called?
Biodiversity
An ecosystem contain a range of…
Habitats
What is one way to measure the size of a population in a habitat?
Use a quadrat
To find out the population of a species in a habitat what would you do? (Clue: State the method)
- Calculate area of habitat
- Measure number of individuals in one quadrat and repeat 3 times
- Calculate average number of individuals in quadrat
- Calculate how many quadrants fit into the total area
- Multiply the result from step4 by the result from step 3
What is random sampling?
It makes our data valid as it avoids choosing areas which may be interesting which would bias our results
How do you take a random sample?
- Lay out two tape measures a right angles to make a 10m by 10m axis
- Generate a random pair of numbers between 1 and 10
- Use these as coordinates to place your quadrat
How do you measure a population? (Clue: Quadrats)
- Count the number of individuals of the chosen species in the square
What is a community?
The populations of all the species present in an ecosystem at a particular time
In what three ways do species in a community interact with each other and the physical environment?
- Feeding on each other
- Competition for resources (e.g food, mates, nesting sights)
- Using abiotic resources (e.g absorbing mineral ion from the soil)
What do arrows mean in a food chain?
“Is eaten by”
What are the stages in a food chain called?
Trophic levels
