KA2- Distribution Of Organisms Flashcards
Abiotic factors
Non living, physical factors that affect where living things are found
Temperature
Increasing temperature reduces oxygen concentration of water
Tool to measure temperature
Thermometer
Sources of error when using thermometer
Placing in direct sunlight
Holding in hand
Not repeating
To minimise error when using thermometer
Don’t leave in direct sunlight
Don’t hold bulb until temperature settled
To improve reliability when using thermometer
Take samples
Yyyyyyy
Ehhhhhh
Tool to measure pH (how)
pH meter
Push probe into soil and read meter
Source of error when using pH meter
Not cleaned between readings
To minimise error when using using pH meter
Repeat and take multiple readings
Wipe probe between readings
To improve reliability when measuring pH
Take samples
Quadrats
For sampling organisms
Estimate number or abundance of plants or animals that don’t move
Sources of error when using quadrats
Some samples may be partly in and out of quadrat
To minimisie error when using quadrats
Place quadrat randomly
Consistent rules to decide if plants or animals are in or out of quadrat
To improve reliability when using quadrats
Look at results of many quadrats
Pitfall traps
Dig a hole, leave a plastic cup in the hole and cover it with leaves
Sources of error when using pitfall traps
Birds can eat animals
Animals can fly out
Animals can eat eachother
To minimise error when using pitfall traps
Place cover on trap
Check trap regularly
Transect lines
Rope/ string (etc) across habitat or part of a habitat
Show effect of changing conditions on types of organisms present
To asses water quality of rivers, streams etc
Fresh water invertebrates
Lichens
Simple plants that grow on the bark of trees that show the level of sulphur dioxide and nitrous oxide oresent
Sulphur oxide
Produced by burning fossil fuels (coal, gas and oil)
Less in the air means more (healthy) species of lichens
Indicator species
The presence or absence of some specific species tells us the level of pollution and level of oxygen because different organisms tolerate different oxygen: pollution levels
Level of pollution increases as oxygen level decreases
Low pollution—>High pollution
Stonefly/mayfly, freshwater shrimp, water louse, blood mouse, rat tailed maggot
