biodiversity within a community

Question 1

what is biodiversity

Answer 1

variety of living organisms

can relate to a range of habitats from small to the earth

Question 2

what are the three components of biodiversity

Answer 2

species diversity
genetic diversity
ecosystem diversity

Question 3

what is a community

Answer 3

all populations of different species in a habitat

Question 4

what is species richness

Answer 4

the number of different species in a community

Question 5

what does the index of diversity show

Answer 5

describes relationship between
- number of species in a community (species richness) and number of individuals in each species (population size)

Question 6

why is the index of diversity a more useful measure than species richness

Answer 6

takes into account number of individuals in each species
so takes into account that some species may be present in small or high numbers

Question 7

how to calculate index of diversity

Answer 7

d = N(N-1)
———
sum of n(n-1)

d- species diversity index
n- total number of organisms of each species
N - total number of organisms of all species

Question 8

what does a high index of diversity mean

Answer 8

many species present
all species evenly represented
ecosystem more stable and resilient to change

Question 9

what does a low index of diversity mean

Answer 9

habitat dominated by a few species
unstable and less likely to come with change

Question 10

what farming techniques can reduce biodiversity and why

Answer 10

removal of woodland and hedgerows
monoculture
use of herbicides to kill weeds
- reduces variety of plants
- so fewer habitats and niches
- and less variety of food sources

use of pesticides to kill pest
- predator population of pest decreases

Question 11

what is the balance between conservation and farming

Answer 11

conservation is required to increase biodiversity
but it can reduce yield and income for farmer
eg. reducing land area from crop growth increasing competition so increased pest population
grants are offered by EU

Question 12

what are some examples of conservation techniques that increase biodiversity without lowering yield

Answer 12

reintroduction of field margins and hedgerows
reduce use of pesticides
growing different crops in same area
using crop rotation i’d nitrogen fixing crops instead of fertiliser