Unit 10- Ecology (definitions and fieldwork) Flashcards
What is A biosphere:
The part of planet earth where life occurs
What is an ecosystem?
A self contained area with all its living organisms, eg oak forest, sand dunes
What is a Biome?
A region of the world with a particular climate, animals and plants
What is a habitat?
The physical or abiotic part of an ecosystem, ie most ecosystems have many habitats, eg oak tree
What is a micro habitat?
A localised specific habitat within a larger habitat, eg under a rotting log
What is a community?
The living or biotic part of the ecosystem, ie all the organisms f all the different species in one habitat
What are the biotic and abiotic factors?
Biotic: any living biological factor
Abiotic: any non-living or physical factor
What is the population?
The number of members of the same species living in 1 habitat
Explain the process of random sampling:
- it is used when you want a representative sample of the whole biota
1) place measuring tapes like axes of a graph
2) generate random numbers from a random number generator
3) let these be the coordinates for the sample
4) repeat to obtain a large number of samples
4+) this minimises the chances of getting a skewed sample reducing anomalies, aim to cover 2% of the total sample space
What are the 3 kinds of systematic sampling?
Line transect
Continuous Belt transect
Interrupted belt transect
When should transect be used?
When measuring an environmental gradient, eg down a mountain side
What is the difference between a line and belt transect?
Line- records all the organisms touching a piece of string stretched along the transect
Belt- quadrants are placed at intervals along the transect and the organisms are counted in the quadrat
Pros and cons of a line transect
+ Quick and easy
- can give unrepresentative data
How do we measure abiotic factors?
- with electronic probes and sensors
Temperature probe, pH probe, light sensor
What are the advantages of using devices to measure abiotic factor?
Measurements are quick, quantities, accurate and can be automatically recorded at regular times
Why do we need to repeat measure abiotic factors?
To account for daily/seasonal variation
To find an reliable average result
To find a causal relationship between abiotic and biotic factors
How can we measure abundance of wood lice in a square meter?
Use the capture-mark-recapture technique
What biotic factors could be measured?
Distribution Diversity Growth Biomass Abundance
How can we work out what sized quadrat to use for sampling?
Refer to the species-area graph
What different quadrants are there?
Point quadrat
Frame quadrat
Frame grid quadrat
How can we capture animals for sampling?
Nets, eg sweep nets, Dnets
Traps: eg pitfall traps, Longworth traps, light traps
How does capture recapture method work?
1) Capture a sample of animals
2) Count all the animals in this sample (S1) and mark them in a way that doesn’t harm them
3) Release all the animals where they were caught, give them time to mix
4) capture a second sample, count the number of animals in sample 2 (S2) and number of recaptured (R)
5) population = (S1)(S2)/R
