Pack 12 - Biodiversity

Question 1

Define Habitat

Answer 1

The place where the organism lives

Question 2

Define ecosystem

Answer 2

All the biotic and abiotic factors in a particular area

Question 3

Define community

Answer 3

All organisms (from different species) living together in one habitat

Question 4

What is species richness?

Answer 4

When you count the number of different species in a habitat

Question 5

What does the Species Diversity Index reflect?

Answer 5

The number of different species present

The number of individuals in each species

Question 6

How do you calculate Species Diversity?

Answer 6

D=N(N-1)/‘thesumof’n(n-1)
D=Diversity Index
N=Total number of organisms of all species
n=Total number of organisms in a particular species

Question 7

What must you do to the table when calculating Species Diversity?

Answer 7

Add the n(n-1) columns

Question 8

How do you know from your calculation which habitat is more diverse?

Answer 8

The greater the value, the greater the Species Diversity Index

Question 9

What the values of D mean?

Answer 9

A high value of D indicates a stable and ancient site e.g a meadow or old woodland with a very diverse community
A low value of D may suggest agricultural management,a recently deforested site/polluted area

Question 10

How do we measure the Species Diversity Index without taking up too much time and without damaging the environment?

Answer 10

Take small samples of an area which is representative of the community of a whole

Question 11

What three ways are organisms distributed?

Answer 11

Random
Regular
Clumped

Question 12

What is the method of random sampling?

Answer 12

Grid is laid out across sample
Random numbers generated to create coordinates to place quadrats
Each quadrat the community is samples, each organism is counted in the quadrat and the number of species is counted
You have to use lots of quadrats

Question 13

How many quadrats are required for a representative sample?

Answer 13

At least 20 quadrats

Question 14

What is the impact of agriculture on Species Diversity?

Answer 14

Removed crops creates a monoculture to provide ideal conditions for one crop to grow
Weeds and pests are removed which will compete for the crops resources
Hedgerows, field boundaries, unprofitable pockets of land and marshy areas are removed to allow for maximum land use for one crop
Very low Species Diversity