3.4.6 Biodiversity in a community

Question 1

What is species richness

Answer 1

(A measure of) the number of (different) species in a community;

Question 2

Why is calculation of index of diversity more
reliable than species richness?

Answer 2

(Index of diversity also) measures abundance / number / population (size) of each species;
(So useful because) may be many of some species

Question 3

Suggest one reason the scientists used biomass
instead of the number of individuals of each plant
species when collecting data to measure diversity.

Answer 3

Individual organisms could not be identified/separated OR
Too small/numerous to count individuals

Question 4

Outline a method the ecologists could have used
to determine the plant species richness at one
site.

Answer 4

1. A method of selecting sampling sites at random e.g. random number generator
2. Use of quadrat;
3. Identify (plant) species (at site / in each quadrat)

Question 5

Pros and Cons to farmer for
Planting Hedges

Answer 5

(Pros)
1. Greater (bio)diversity so increase in predators of pests
2. Increase in predators of pests so more yield/income
3. Increase in pollinators so more yield/income
(Cons)
1. Reduced land area for crop growth/income
2. Greater (bio)diversity so increase pest population
3. Increase pest population so less yield/income
4. Increased competition so less yield/income

Question 6

Suggest one ethical argument for maintaining
biodiversity.

Answer 6

Prevent extinction / loss of populations / reduction in populations / loss of habitats

Question 7

Suggest one economic argument for maintaining
biodiversity.

Answer 7

Medical or pharmaceutical uses of plants
Tourism
Agriculture
Saving forest communities