4.2.1 biodiversity

Question 1

What levels can biodiversity be studied at?

Answer 1

Habitat biodiversity.
Species biodiversity.
Genetic biodiversity.

Question 2

What is habitat biodiversity?

Answer 2

Habitat biodiversity refers to the number of different habitats found within an area.
e.g. meadow, woodland, streams, and sand dunes.

Question 3

What is species evenness?

Answer 3

A comparison of the numbers of individuals of each species living in a community.

Question 4

What is species richness?

Answer 4

The number of different species living in a particular area.

Question 5

What components make up species biodiversity?

Answer 5

Species richness and species evenness make up species biodiversity.

Question 6

What is genetic biodiversity?

Answer 6

Genetic biodiversity refers to the variety of genes that make up a species.

Question 7

What does greater genetic biodiversity within a species lead to?

Answer 7

Greater genetic biodiversity within a species allows for better adaptation to a changing environment, and is more likely to result in individuals who are resistant to disease.
Leads to quite different characteristics being exhibited-different breeds within a species.

Question 8

What is an Environmental Impact Assessment (EIA)?

Answer 8

EIAs attempt to predict the positive and negative effects of a project on the biodiversity in that area.

Question 9

What is sampling?

Answer 9

Sampling is taking measurements of a limited number of individual organisms present in a particular area.

Question 10

What is the abundance of organisms?

Answer 10

The number of individuals of a species present in an area.

Question 11

What is random sampling?

Answer 11

Random sampling means selecting individuals by chance.
Each individual in the population has an equal likelihood of selection.

Question 12

What is non-random sampling?

Answer 12

Non-random sampling is an alternative sampling method where the sample is not chosen at random.

Question 13

What is opportunistic non-random sampling?

Answer 13

This is the weakest form of sampling as it may not be representative of the population.
Opportunistic sampling uses organisms that are conveniently available.

Question 14

What is stratified non-random sampling?

Answer 14

Some populations can be divided into a number of strata (sub-groups) based on a particular characteristic.
For instance, the population might be separated into males and females.
A random sample is then taken from each of these strata proportional to its size.

Question 15

What is systematic non-sampling?

Answer 15

In systematic sampling different areas within an overall habitat are identified, which are then sampled separately.
Systematic sampling is often carried out using a line or a belt transect.

Question 16

What does a belt transect provide?

Answer 16

A belt transect provides more information: two parallel lines are marked, and samples are taken of the area between the two lines.

Question 17

What does a line transect involve?

Answer 17

A line transect involves marking a line along the ground between two poles and taking samples at specified points.

Question 18

What is sampling bias?

Answer 18

The selection process may be biased.
The effects of sampling bias can be reduced using random sampling, where human involvement is removed.

Question 19

How can chance reduce reliability in entire representation of organisms in a habitat?

Answer 19

The organisms selected may by chance, not be representative of the whole population.
Chance can never be removed from the process, but its effect can be minimised by using a large sample size.

Question 20

How can animals be sampled?

Answer 20

A pooter.
A sweepnet.
A pitfall trap.
Tree beating.
Kick sampling.

Question 21

What is a pooter?

Answer 21

A pooter is used to catch small insects.

Question 22

When is a sweep net used?

Answer 22

Sweep nets are used to catch insects in areas of long grass.

Question 23

How is a pitfall trap used?

Answer 23

Pitfall traps are used to catch small, crawling invertebrates such as beetles, spiders and slugs.
A hole is dug in the ground, which insects fall into.

Question 24

What are the main types of quadrats?

Answer 24

A point quadrat.
A frame quadrat.

Question 25

What is a point quadrat?

Answer 25

This consists of a frame containing a horizontal bar.
At set intervals along the bar, long pins can be pushed through the bar to reach the ground.
Each species of plant the pin touches is recorded.

Question 26

What is a frame quadrat?

Answer 26

This consists of a square frame divided into a grid of equal sections.
The type and number of species within each section of the quadrat is recorded.

Question 27

What are the three main ways to use a frame quadrat to sample the population of plants living in a habitat?

Answer 27

Density- if individual large plants can be seen clearly, count the number of them in a 1m by 1m square quadrat. Allows to give the density per square metre.
Frequency- count the number of squares a particular species is present in.
Percentage cover- useful when a particular species is abundant or difficult to count.

Question 28

What is the capture-mark-release-recapture method?

Answer 28

Capturing as many individuals of a species in an area as possible.
The organisms are marked and then released back into the community.
Time is allowed for the organisms to redistribute themselves through the habitat before another sample of animals are collected.

Question 29

What are abiotic factors?

Answer 29

Abiotic factors are the non-living conditions in a habitat.

Question 30

Why are abiotic factor sensors advantageous?

Answer 30

Rapid changes can be detected.
Human error in taking a reading is reduced.
A high degree of precision can often be achieved.
Data can be stored and tracked on a computer.

Question 31

What is Simpson’s Index of Diversity?

Answer 31

Simpson’s Index of Diversity is a better measure of biodiversity as it takes into account species evenness and richness.

Question 32

What does the value represent in Simpson’s Index of Diversity?

Answer 32

Simpsons’s Index of Diveristy always results in a value between 0 and 1, where 0 represents no diversity and 1 represents infinite diversity.
The higher the value the more diverse the habitat.

Question 33

Why is conserving low biodiversity habitats just as important as high biodiversity habitats?

Answer 33

In order to conserve rare species that may be too specialised to survive elsewhere.

Question 34

What is the importance of genetic biodiversity?

Answer 34

Species that contain greater genetic biodiversity are likely to be able to adapt to changes in the environment, and are less likely to become extinct.
It is likely some organisms within the population that carry an advantageous allele.

Question 35

How can the number of possible alleles in a population increase?

Answer 35

Mutations- creating a new allele.
Interbreeding between different populations- alleles are transferred between the two populations (gene flow).

Question 36

How can the number of possible alleles in a population decrease?

Answer 36

Selective breeding.
Captive breeding programmes.
Rare breeds.
Artificial cloning (asexual reproduction).
Natural selection.
Genetic bottlenecks.
Founder effect.
Genetic drift.

Question 37

What is the founder effect?

Answer 37

The founder effect is where a small number of individuals create a new colony, geographically isolated from the original.

Question 38

What are genetic bottlenecks?

Answer 38

Genetic bottlenecks are where a few individuals within a population survive an event or change, thus reducing the ‘gene pool’.
Only the alleles of the surviving members of the population are available to be passed on to offspring.

Question 39

How can the proportion of polymorphic gene loci be calculated?

Answer 39

proportion of polymorphic gene loci = number of polymorphic gene loci / total number of loci.

Question 40

What are the main problems caused by human influence on biodiversity?

Answer 40

Deforestation.
Agriculture.
Climate change.

Question 41

How does deforestation affect biodiversity?

Answer 41

It directly reduces the number of trees present in an area.
If only a specific type of tree is felled, the species diversity is reduced.
It reduces the number of animal species present in an area as it destroys their habitat, in turn reduces the number of other animals species that are present.
Animals are forced to migrate to other areas to ensure their survival.

Question 42

How does agriculture reduce biodiversity?

Answer 42

Deforestation- to increase the area of land available for growing crops or rearing animals.
Removal of hedgerows- farmers remove hedgerows to enable them to use large machinery. This reduces the number of plant species present in an area and destroys the habitat of animals.
Use of chemicals such as pesticides and herbicides- reduces species diversity directly as it destroys the pest species.
Herbicides used to kill weeds- plant diversity is reduced directly.
Monoculture- local effect in lowering biodiversity as only one species is present.

Question 43

What evidence is there for climate change?

Answer 43

The warming trend over the last 50 years is nearly twice that for the previous 100 years.
Average Artic temperatures have increased at almost twice the global average rate in the past 100 years.
Long-term upward trends in the amount of precipitation have been observed over many regions from 1900 to 2005.

Question 44

How will global warming affect biodiversity if it continues?

Answer 44

The melting of polar ice caps- could lead to extinction of plant and animal species.
Rising sea levels- low-lying land, and reducing the available terrestrial habitats.
High temperatures and less rainfall- leading to drought-resistant species becoming more dominant.
Insect life cycles and populations.

Question 45

What are the main reasons biodiversity has to be maintained?

Answer 45

Aesthetic reasons.
Economic reasons.
Ecological reasons.

Question 46

What are the aesthetic reasons for maintaining biodiversity?

Answer 46

The presence of different plants and animals in our environment enriches our life.
The natural world provides inspiration for people e.g. musicians and artists.
Studies show that patients recover more rapidly from stress and injury when supported by plants.

Question 47

What are the economic reasons for maintaining biodiversity?

Answer 47

Soil erosion and desertification may occur as a result of deforestation- reduce a country’s ability to grow crops and feed it’s people.
Important to reserve all organisms that we use to make things. Non-sustainable removal of resources will eventually lead to the collapse of industry in an area.
Large-scale habitat and biodiversity losses mean that species with potential economic importance may become extinct before they are even discovered.
Attractive areas can be used for tourist areas.

Question 48

What are ecological reasons for maintaining biodiversity?

Answer 48

All organisms are interdependent on others for their survival.
Some species play a key role in maintaining the structure of an ecological community- keystone species.

Question 49

What is conservation?

Answer 49

Conservation is the preservation and careful management of the environment and of natural resources.

Question 50

What is in situ conservation and ex situ conservation?

Answer 50

In situ conservation- within the natural habitat.
Ex situ conservation- out of the natural habitat.

Question 51

What are examples of in situ conservation?

Answer 51

Wildlife reserves.
Marine conservation zones.

Question 52

What are examples of ex situ conservation?

Answer 52

Botanic gardens.
Seed banks.
Captive-breeding programmes.

Question 53

What are some active-management techniques?

Answer 53

Controlled grazing.
Restricted human access.
Feeding animals.
Reintroduction of species.
Culling or removing invasive species.
Halting succession.

Question 54

Why may some organisms born in captivity not be suitable for release?

Answer 54

Diseases.
Behaviour.
Genetic races.
Habitat.

Question 55

What is the International Union for Conservation of Nature (IUCN)?

Answer 55

Assist in securing agreements between nations.
Publishes a Red List- detailing the current conservation status of threatened animals.

Question 56

What is CITES?

Answer 56

Convention on International Trade in Endangered Species.
Treaty regulates the international trade of wild plants and animal specimens and their products.

Question 57

What did the Rio convention of 1992 lead to?

Answer 57

New agreements:
The Convention on Biological Diversity (CBD) requires countries to develop national strategies for sustainable development.
The United Nations Framework Convention on Climate Change (UNFCCC) is an agreement between nations to take steps to stabilise greenhouse gas concentrations.
The United Nations Convention to Combat Desertification (UNCCD) aims to prevent the transformation of fertile land into desert and reduce the effects of drought.

Question 58

What are the aims of the Countryside stewardship scheme?

Answer 58

Sustaining the beauty and diversity of the landscape.
Improving, extending and creating wildlife habitats.
Restoring neglected land and conserving archaeological and historic features.
Improving opportunities for countryside enjoyment.