Sampling-life On Earth Flashcards
Give 2 reasons why it’s impossible to sample a whole ecosystem
- it would be too time consuming
* too many organisms to count without making an error
What does sampling allow you to do?
Sampling allows a representative picture of the types and numbers of organisms present to be determined
Name 4 sampling techniques
- Quadrat
- pitfall trap
- tree beating
- tullgren funnel
Name 2 limits to a quadrat and how you would solve these problems
- organisms wrongly identified-have a key to identify unknown organisms
- counted incorrectly/inconsistently-have a counting rule (half out the quadrat is either counted or not counted)
Give 2 limits of a pitfall trap and how you would solve these problems
- flying organisms can fly out-make a lid
* animals may drown-needle holes to drain water
Name a limit of tree beating and how you would solve it
Animals may not fall onto the sheet or tray- have a big sheet/tray and move it to where you are beating
Name 2 limits to a tullgren funnel
- animals may die in soil before reaching collecting jar-place only a thin layer of soil
- animals may be too large to pass through mesh funnel-mesh should have holes of different sizes
What do you measure light intensity with?
Name a limit and how you would solve the problem
A light meter
Shaded by user- stand to the side at arms length
What do you measure temperature with?
Name a limit and how you would solve the problem
A thermometer
Bulb held in hand- don’t hold the bulb!!
What do you measure pH with?
Name a limit and how you would solve the problem
A pH meter
It could be contaminated from last sample- wipe probe between sampling
What do you measure soil moisture with?
Name a limit and how you would solve the problem
A moisture meter
It could be contaminated from last sample- wipe probe between sampling
What do keys allow?
They allow easy identification of unknown organisms
What’s a paired statement key?
There is a numbered list of statements, Choose the best fitting two statements and follow onto the next statement it leads onto
What is a branched key?
It is structured in branches instead of statements, find the matching branch and work your way down until you have identified the organism
What is a transect?
A transect is a sample strip of land used to monitor plant distribution, animal populations etc. within a given area
