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Flashcards in Biodiversity Deck (23)
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1
Q

Define biodiversity

A

The variety of living organisms in an area.

2
Q

What 3 levels can biodiversity be considered at?

A
  • Habitat diversity
  • Species diversity
  • Genetic diversity
3
Q

Define species

A

A group of similar organisms able to reproduce to give fertile offspring

4
Q

Define habitat

A

The area inhabited by a species. Including physical factors, like soil and temperature range, and living (biotic) factors, like avalibility of food or presence of a predator

5
Q

Define habitat diversity

A

The number of different habitats in an area, e.g. a particular area could contain many different habitats- Sand dunes, woodland, meadows, streams etc.

6
Q

Define species diversity

A

The number of species (species richness) and the abundance of each species (species evenness) in an area

7
Q

Define genetic diversity

A

The variation of alleles within a species (or population of a species) e.g. variation of alleles within dog species would give rise to different breeds.

8
Q

What is sampling used for?

A

Measuring biodiversity

9
Q

Why is sampling used to measure biodiversity?

A

Because it’s too time consuming to count each individual organism in a habitat/impossible

10
Q

How might you sample (generally)

A
  • Choose an area to sample (a small area within the habitat being studied)
  • Count the no. of individuals of each species (how this is done depends on what you’re counting)
  • Repeat process
  • Use results to estimate total no. of individuals/different species
11
Q

Why must you sample as many times as possible?

A

-To get the best indication of the whole habitat

12
Q

If comparing habitats, what should the sampling used be?

A

-The same for both habitats

13
Q

What are the two types of sampling?

A

Random and non random

14
Q

Why is random sampling better than non-random?

A

Because it helps avoid bias created by the researcher

15
Q

How might you randomly sample?

A
  • Divide the field up into a grid using measuring tape
  • Give each square coordinates
  • Use a random number generator to select the coordinates
16
Q

Why may a non-random sample be necessary?

A

-When there’s a lot of variety in the distribution of species in a habitat and you want to ensure all differnt areas are sampled

17
Q

What are the 3 types of non-random sampling?

A
  • Systematic
  • Opportunistic
  • Stratified
18
Q

Describe systematic sampling

A

-When sampling is taken at fixed intervals, often along a line e,g, quadrats could be placed in a line (transect) from an area of shade in the corner to the middle of a field

19
Q

Describe opportunisitc sampling

A
  • When samples are chosen by the investigator.
  • Used because it’s simpe to carry out
  • Data will be biased
20
Q

Describe stratified sampling

A

-When differnet areas in a habitat are identified and sampled separately in proportion to their part of the habitat as a whole

21
Q

Describe species richness

A
  • The number of different species in an area.
  • The higher the number of species the greater the species richness
  • Count the number of differnt species
22
Q

What sampling is typically used for measuring species richness and evenness?

A

Random sampling

23
Q

Describe species evenness

A
  • Is a measure of the relative abundance of each species in an area.
  • The more similar the population sizes of each species, the greater the species evenness
  • Count the no. of individulas of each species