Biodiversity within a community

Question 1

Biodiversity

Answer 1

variety of living organisms in an area. it has 3 components:

Species diversity
Genetic diversity
Ecosystem Diversity

Question 2

Species diversity

Answer 2

The number of different species and the number of individuals of each species in a community.

Question 3

What are the two different levels of biodiversity

Answer 3

Local biodiversity (ponds/meadow)

Global diversity- variety of species living on earth

Question 4

Species richness

Answer 4

Number of different species in a community.

Question 5

Index of biodiversity

Answer 5

Describes the relationship between the number of species in a community and the number of individuals in each species.

Index of diversity (D)= N(N-1)
——————–
E n(n-1)

N= total number of organisms of all species
n=total number organisms of each individual species
E= sum of

Question 6

What does index of diversity show

Answer 6

The greater the species richness and species evenness, the higher the number of D

lowest value of D=1. So anything larger than the value of D the greater the diversity

Question 7

Why is Index of diversity a useful measure of species diversity

Answer 7

Measures the number of individual in a species and takes into account that some species may be present in low/high numbers.

Question 8

Farming techniques that reduce biodiversity

Answer 8

Removal of woodland and Hedgerows
Monoculture (one crop)
Use of pesticides, herbicides and inorganic fertilisers
Crops better competitors for resources such as light and nutrients

which:
Reduces variety of plants
So fewer habitats and niches
less variety of food sources

Question 9

Conservation techniques which can increase biodiversity

Answer 9

-Use crop rotation of nitrogen fixing crops instead of fertilisers

-Maintain hedgerows and plant new hedges instead of using fences .

-Reduce pesticides

Question 10

Exam question example:

Farmers clear tropical forests and grow crops instead. explain how this causes the diversity of insects in the area to decrease? (3 marks)

Answer 10

-Less variety of plants
-fewer habitats
-Fewer variety of food sources
-pesticides kills insects.