🩶 3.4 Topic 4 - 3.4.6 Biodiversity within a community

Question 1

give a definition for biodiversity

Answer 1

the number and variety of living organisms in a particular area.

Question 2

give a definition for habitat

Answer 2

the place where an organism lives.

Question 3

give a definition for community

Answer 3

all the populations of different species in a habitat.

Question 4

give a definition for a species

Answer 4

a group of similar organisms which are able reproduce to give fertile offspring.

Question 5

what does it mean if areas have high biodiversity?

Answer 5

that there are lots of different species.

Question 6

what are the two levels biodiversity can be considered at?

Answer 6

Local and global.

Question 7

give a definition for local biodiversity

Answer 7

variety of different species living in a small habitat that’s local to you.

Question 8

give a definition for global biodiversity

Answer 8

variety of different species on earth.

Question 9

what 3 components [beginning with S, G and E] does biodiversity have?

Answer 9

species diversity, genetic diversity and ecosystem diversity.

Question 10

what does species diversity refer to?

Answer 10

refers to the number of different species and the number of individuals of each species within any one community.

Question 11

what does genetic diversity refer to?

Answer 11

refers to the variety of genes possessed by the individuals that make up a population of a species.

Question 12

what does ecosystem diversity refer to?

Answer 12

refers to the range of different habitats, from a small local habitat to the whole of the earth.

Question 13

what is the measure of species diversity called?

Answer 13

species richness.

Question 14

give a definition for species richness

Answer 14

a measure of the number of different species in a community.

Question 15

what does an index of diversity describe?

Answer 15

the relationship between the number of species in a community (species richness) and the number of individuals in each species.

Question 16

give the index of diversity formula

Answer 16

d = N (N- 1) / £n(n - 1)

Question 17

what does the N in the index of diversity formula mean?

Answer 17

total number of organisms of all species.

Question 18

what does the n in the index of diversity formula mean?

Answer 18

total number of organisms of each species.

Question 19

what does the £ in the index of diversity formula mean?

Answer 19

the sum of.

Question 20

The number of species in a community and the abundance of each species is also known as the …

Answer 20

… species diversity

Question 21

what does a high value of the index of diversity mean?

Answer 21

the species diversity is high.

Question 22

If all the individuals are of the same species (no biodiversity), what is the index of diversity?

Answer 22

1.

Question 23

what techniques reduce biodiversity?

Answer 23

farming and agriculture.

Question 25

what do natural ecosystems become after developing over time?

Answer 25

complex communities with many individuals of a large number of different species – these communities have a high index of diversity.

Question 26

what happens to the number of species when farmers select species for particular qualities that make them more productive?

Answer 26

the number of species, and the genetic variety of allele they possess is reduced to the few which exhibit the desired features.

Question 27

list 4 ways agricultural practices can reduce biodiversity:

Answer 27

monoculture, deforestation(woodland clearance), hedgerow removal, pesticides and herbicides.

Question 28

how do monocultures reduce biodiversity?

Answer 28

+ when crops are grown on a large scale for agriculture, a single crop (a monoculture) species covers many fields.
- monocultures directly remove species and fewer species can survive in monoculture environments.

Question 29

how does deforestation/woodland clearance reduce biodiversity?

Answer 29

+ large regions of forests are cleared to provide space for farming.
+ forests are biodiverse environments because there are many different habitats for different species.
- direct removal of species and removal of habitats causing species to die.

Question 30

how does hedgerow removal reduce biodiversity?

Answer 30

+ done to increase farmland by turning lots of small fields into fewer large fields.

Question 31

how do pesticides reduce biodiversity?

Answer 31

+ pesticides are sprayed onto crops to prevent pests e.g. slugs from feeding on crops.
- direct removal of pests and species that feed on the pests cannot survive as lose a food source.

Question 32

how do herbicides reduce biodiversity?

Answer 32

+ herbicides are sprayed onto crops to prevent growth of unwanted plants and weeds.
- direct removal of plants and species that feed on unwanted plants cannot survive.

Question 33

what schemes can help avoid the impacts of agriculture?

Answer 33

conservation schemes.

Question 34

how do conservation schemes help avoid the impacts of agriculture?

Answer 34

: endangered species can be legally protected to avoid extinction.
: specific areas with high biodiversity can be protected (cannot be developed into farmland).
: farmers are encouraged to balance agriculture with conserving biodiversity.

Question 35

What are 3 examples of conservation schemes?

Answer 35

Giving legal protection to endangered species.
Creating protected area such as SSSIs (Sites of Special Scientific Interest) and AONBs (Areas of Outstanding Natural Beauty). These restrict further development, including agricultural development.
The Environmental Stewardship Scheme which encourages farmers to conserve biodiversity e.g. by replanting hedgerows and leaving margins around fields for wild flowers to grow.

Question 36

what are 4 direct removals of habitats, reducing species diversity?

Answer 36

> removing hedgerows and grubbing out woodland.
creating monocultures, for example replacing natural meadows with cereal crops or grass for silage.
filling in ponds and draining marsh and other wetland.
over-grazing of land, for example, upland areas by sheep, thereby preventing regeneration of woodland.

Question 37

what are 3 indirect removals of habitats, reducing species diversity?

Answer 37

< use of pesticides and inorganic fertilisers.
< escape of effluent from silage stores and slurry tanks into water courses.
< absence of crop rotation and lack of intercropping or undersowing.

Question 38

what happens if biodiversity is reduced?

Answer 38

the global living system becomes increasingly unstable and we all rely on the global system for food and other resources.

Question 39

what two things need to be balanced so we don’t lose too much biodiversity?

Answer 39

agriculture and conservation.