Biodiversity

Question 1

Sampling

Answer 1

Used to estimate the number of organisms in a given area (abundance)

• can also measure a particular characteristic e.g. average height of a crop

Question 2

Types of sampling

Answer 2

• Random
• non random- opportunistic, systematic, stratified

Question 3

Opportunistic

Answer 3

Uses organisms that are conveniently available

Question 4

Stratified

Answer 4

Populations divided into strata (subgroups) and then randomly sampled e.g. male and female

Question 5

Systematic

Answer 5

Carried out using a line or belt transect. Samples taken systematically (following a set pattern)

Question 6

Reliability

Answer 6

Samples can never be entirely representative of abundance of organisms

You can reduce the likelihood of these 2 issues:
1. Sampling bias- use random sampling
2. Chance- use larger sample size (repeat it more times)

Question 7

Ethical considerations when sampling animals

Answer 7

• always handle animals carefully and for a short a time as possible
• animals must always be released as soon as they have been identified, counted and measured

Question 8

Animal sampling techniques

Answer 8

Pooter- catching small insects

Sweep net- catching insects in long grass

Kick sampling- study organisms in a river

Tree beating- catch invertebrates living in trees or bushes

Pitfall traps- catch small crawling invertebrates

Question 9

Sampling plants- transects

Answer 9

Belt transect
- best
- provides more information on abundance

Point quadrants
- each species that the pins touch are counted

Frame quadrants
Used to calculate:
- density: exact number of organisms
- frequency: number of squares containing organisms are counted. Useful for plants such as moss or grass. E.g. 60/100 squares contain moss, frequency = 60%
- percentage cover: estimation by the eye of the % of the quadrat covered by an organism

Question 10

Species richness

Answer 10

The number of species per sample

• more species present, the richer the sample is
• takes no account of the number of individuals of each species present
• e.g. 1 daisy has as much influence on the richness of an area as 1000 buttercups, both still have a richness of 1

Question 11

Species evenness

Answer 11

Relative abundance of different species making up the richness of an area

Example

Sample 1 Sample 2
Daisy: 300 20
Dandelion: 335 49
Buttercup: 365 931
Total: 1000 1000

• Sample 1 and sample 2 are taken from two different fields
• total number of individuals and species richness are the same but 1 has more evenness

Question 12

Measuring biodiversity

Answer 12

A community dominated by 1 or 2 species is less diverse than one in which several different species have a similar abundance

• as species richness and evenness increase, so does biodiversity

Question 13

Simpson’s index

Question 14

Polymorphism

Answer 14

Genetic polymorphism occurs when there are 2 or more alleles present at a single loci

• polymorphic loci have multiple alleles
• most common allele must have frequency if less than 95-99%
• if more than this, alleles are extremely rare
• monomorphic is a locus that doesn’t have multiple alleles/one allele

Question 15

Proportion of polymorphic gene loci

Answer 15

number of polymorphic gene loci
Total number of loci

• gives P

Question 16

Limitations of P

Answer 16

• the proportion of polymorphic genetic loci (P) does not illustrate the allele richness of a breed or species

Question 17

Polymorphic gene

Answer 17

A gene with more than one allele

Question 18

Factors affection biodiversity (8)

Answer 18

• climate change
• predators
• water and food availability
• extinction
• invasive species
• deforestation
• poaching
• human: population growth, agriculture

Question 19

Deforestation

Answer 19

• directly reduces tree numbers
• reduces species richness/evenness by felling only certain types of trees
• destroys habitats- reduces animals species present
• forces animals to migrate
• contributes to global warming - less CO2 sequestered

Question 20

Agriculture

Answer 20

Monoculture
- removal of biodiverse land to grow only one type of crop
- fewer animal species supported

Chemicals
- pesticides and herbicides

Question 21

Removal of hedgerows

Answer 21

• reduces plants species present
• destroys habitats of many birds, mammals and invertebrates

Question 22

Climate change IPCC findings

Answer 22

• sea levels risen
• average arctic temperature increased at twice the average global rate from last 100yrs
• snow cover declined in both hemispheres
• upwards trend in participation

Question 23

Global warming

Answer 23

Refers only to the earths rising surface temperature

Question 24

Climate change

Answer 24

Includes warming and the side effects of warming

Question 25

How does climate change affect biodiversity

Answer 25

**Melting polar ice caps** - extinction of plant and animal species - habitat shifts (animals forced to migrate are new competition for animals) **Rising sea levels** - flooding - saltwater entering freshwater habitats **Higher temperatures + less rainfall** - some plant species unable to survive - xerophytes become more dominant

Question 26

Costa Rica

Answer 26

- biodiversity hotspot - covers 0.03% global landmass - contains 5% of earths biodiversity, making it most biodiverse country on the planet

Question 27

Arguments for maintaining biodiversity

Answer 27

1. Aesthetic 2. Economic 3. Ecological

Question 28

Maintaining biodiversity: aesthetic

Answer 28

- attracts millions of tourists each year - landscape provides inspiration for people - relaxation- mental health

Question 29

Maintaining biodiversity: economic

Answer 29

- prevents soil depletion - prevents soil erosion - genetic variation- crops less susceptible to disease - promotes tourism - protecting undiscovered species- medicinal uses

Question 30

Maintaining biodiversity: ecological

Answer 30

- protects keystone species- must be protected to protect entire ecosystems - interdependence of species- plants rely on pollinators

Question 31

Keystone species

Answer 31

A species which has a disproportionately large effect in their environment, relative to their abundance

Question 32

Keystone species examples

Answer 32

**Eurasian beaver**- dam building creates and maintains wetlands, which provides critical habitats and supports biodiversity in freshwater ecosystems (prevents flooding) **Starfish**- predation on mussels and sea urchins prevents them from dominating intertidal zones, maintaining species diversity in marine systems **Grey wolf**- predation on large herbivores like elk and deer prevents plants from being eaten too much

Question 33

How are species classified in a conservation context

Answer 33

1. Lower risk 2. Threatened 3. Extinct

Question 34

Conservation

Answer 34

Preservation and management of the environment and natural resources - in situ- within the natural habitat - ex situ- outside if the natural habitat

Question 35

In situ

Answer 35

**Wildlife reserves** Wildlife reserves are protected areas which must be actively managed: _Active Management_ - control poaching - **culling or removal of invasive species**- the selective killing of members of an animal population in order to reduce the overall population size - reintroduction of species - feeding of animals - **halting succession**- ways that succession can be deliberately prevented e.g. introducing grazing animals to prevent growth of shrubs - restricting human access - **controlled grazing**- management of forage with grazing animals. It limits access to grazing

Question 36

In situ: marine conservation zones

Answer 36

- protection for marine zones which would otherwise be devastated by overfishing - aim is not to prevent fishing in the entire area, but create areas of refuge so that populations can build up - requires large areas of sea- target species move or breed in different areas

Question 37

Ex situ

Answer 37

**Botanic gardens** - plant species are grown through management - nutrients are supplied, watering, pest removal seed banks **Captive breeding programmes** _Purpose_ Programmes can breed individuals of a species so their offspring can be released into the wild _Challenges_ - small species populations can reduces genetic diversity - certain animal species won’t breed in captivity - not all zoos can provide adequate habitats for animals with specific needs - expensive

Question 38

Why organisms may not be related

Answer 38

- genetic mutation - too adapted to life at zoo - not adapted to wild environment- learned behaviour - habitat destruction - susceptible to disease

Question 39

Countryside Stewardship Scheme (CSS)

Answer 39

- provided funding to farmers and private landowners in England who used environmental management strategies to protect and increase the natural biodiversity on their land *scheme was replaced by the Environmental Stewardship Scheme*

Question 40

What do farmers and private landowners have to do to qualify for CSS

Answer 40

- provide and protect valuable wildlife habitats e.g. ponds, hedgerows, buffer zones around farms - ensure their land is managed well, maintaining traditional character - protect any natural resources or historic features present on their land - conserve any traditional crops or livestock present on their land - provide visitor opportunities so people can learn about the countryside and how important it is in sustaining biodiversity

Question 41

International Union for the Conservation of Nature (IUCN)

Answer 41

• the IUCN is described as the “global authority on the status of the natural world and the measures needed to safeguard it” • The main role is assessing the conservation status of animal and plant species around the world Animals that are on the IUCN Red Lost of Threatened Species can be seen online as this list is made public

Question 42

Convention of Biological Diversity (CBD)

Answer 42

The convention has 3 main goals: - conservation of biological diversity by use of a variety of different conservation methods - the sustainable use of biological resources - the fair and equitable sharing of benefits arising from genetic resources

Question 43

Convention on International Trade in Endangered Species (CITES)

Answer 43

- global agreement signed by over 150 countries - it’s aim is to control the trade of endangered species and their associated products E.g. elephants and ivory tusks

Question 44

CITES categories of endangered and vulnerable species:

Answer 44

1: species that are endangered and face the greatest risk of extinction e.g. red panda 2: species that are not currently endangered or facing extinction but will be unless trade is closely controlled e.g. Venus fly trap 3: species included at request of the country that is regulating trade of species and trying to prevent its over exploitation e.g. two toed sloth