Biodiversity within a community

Question 1

define community

Answer 1

all the organisms in all the species in an ecosystem/habitat/area

Question 2

define species richness

Answer 2

how many different species in a community

Question 3

define index of diversity

Answer 3

the number of different species and the number of individuals of each species within a community

Question 4

define genetic diversity

Answer 4

the total number of different alleles in a population of one species

Question 5

define ecosystem diversity

Answer 5

the range of different habitats within a particular area

Question 6

whats the equation for calculating the index of diversity?

Answer 6

d = N(N-1) / Σn(n-1)​

d= index of diversity
N = total number of organisms of all species
n = number of organisms in each species
Σ = sum of

Question 7

what are two human activities that decrease species diversity?

Answer 7

1) deforestation
2) agriculture

Question 8

how does deforestation decrease species diversity?

Answer 8

permanent clearing of forests leads to loss of habitats and in turn loss of biodiversity.
=> fewer different food sources.

Question 9

how does agriculture decrease species diversity?

Answer 9

• woodland clearance
• hedgerow removal
• use of herbicides and pesticides
• monoculture, less room for other species
• fewer different habitats
• fewer plant species
• fewer different food sources

Question 10

how does monoculture cause a decrease in species diversity?

Answer 10

fewer plant species, fewer different food sources => reduces number of different species in the habitat

Question 11

how does use of herbicides reduce species diversity?

Answer 11

fewer plant species, fewer different food sources => reduces number of different species in the habitat

Question 12

how does use of pesticides reduce species diversity?

Answer 12

kills insects that feed on crop plants, fewer different food sources => reduces number of different species in the habitat

Question 13

how does removal of hedgerows reduce species diversity?

Answer 13

fewer different habitats, fewer different food sources => reduces number of different species in the habitat

Question 14

what are the conservation efforts that are being made to promote biodiversity?

Answer 14

• maintain existing hedgerows
• plant new hedges instead of fences
• maintain ponds and create new ones
• leave wet corners of fields
• reduce the use of pesticides and herbicides
• use organic fertilisers
• use crop rotation of nitrogen fixing crops instead of fertilisers