Unit 10- Ecology (definitions and fieldwork)

Question 1

What is A biosphere:

Answer 1

The part of planet earth where life occurs

Question 2

What is an ecosystem?

Answer 2

A self contained area with all its living organisms, eg oak forest, sand dunes

Question 3

What is a Biome?

Answer 3

A region of the world with a particular climate, animals and plants

Question 4

What is a habitat?

Answer 4

The physical or abiotic part of an ecosystem, ie most ecosystems have many habitats, eg oak tree

Question 5

What is a micro habitat?

Answer 5

A localised specific habitat within a larger habitat, eg under a rotting log

Question 6

What is a community?

Answer 6

The living or biotic part of the ecosystem, ie all the organisms f all the different species in one habitat

Question 7

What are the biotic and abiotic factors?

Answer 7

Biotic: any living biological factor
Abiotic: any non-living or physical factor

Question 8

What is the population?

Answer 8

The number of members of the same species living in 1 habitat

Question 9

Explain the process of random sampling:

Answer 9

• 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

Question 10

What are the 3 kinds of systematic sampling?

Answer 10

Line transect
Continuous Belt transect
Interrupted belt transect

Question 11

When should transect be used?

Answer 11

When measuring an environmental gradient, eg down a mountain side

Question 12

What is the difference between a line and belt transect?

Answer 12

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

Question 13

Pros and cons of a line transect

Answer 13

+ Quick and easy

- can give unrepresentative data

Question 14

How do we measure abiotic factors?

Answer 14

• with electronic probes and sensors

Temperature probe, pH probe, light sensor

Question 15

What are the advantages of using devices to measure abiotic factor?

Answer 15

Measurements are quick, quantities, accurate and can be automatically recorded at regular times

Question 16

Why do we need to repeat measure abiotic factors?

Answer 16

To account for daily/seasonal variation
To find an reliable average result
To find a causal relationship between abiotic and biotic factors

Question 17

How can we measure abundance of wood lice in a square meter?

Answer 17

Use the capture-mark-recapture technique

Question 18

What biotic factors could be measured?

Answer 18

Distribution
Diversity
Growth
Biomass
Abundance

Question 19

How can we work out what sized quadrat to use for sampling?

Answer 19

Refer to the species-area graph

Question 20

What different quadrants are there?

Answer 20

Point quadrat
Frame quadrat
Frame grid quadrat

Question 21

How can we capture animals for sampling?

Answer 21

Nets, eg sweep nets, Dnets

Traps: eg pitfall traps, Longworth traps, light traps

Question 22

How does capture recapture method work?

Answer 22

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