L14 - Species richness

Question 1

Describe how geographic is a factor for the number of species richness

Answer 1

• harshness/productivity

- disturbance level

Question 2

What secondary factors effect species richness?

Answer 2

Competition, predation, successional stage

Question 3

What factors of a community that have more species?

Answer 3

Good food resources
Smaller niche breadth
More niche overlap
Resources more fully exploited

Question 4

Explain how predation, isolation and competition all effect species richness

Answer 4

Predation - can reduce species number. But can also just reduce population size causing niche overlap
Isolation - linked to reduced resources
Competition - leads to resources being fully exploited

Question 5

In what part of the world is productivity highest and lowest?

Answer 5

Highest - the tropics

Lowest - at low altitudes and depths

Question 6

Give 2 factors that will increase a resource base

Answer 6

increased productivity, increased heterogeneity

Question 7

Describe how the species richness of the tropics in maintained by a) predation b) climate c) productivity

Answer 7

a) there is a large range of specialised predators, which reduced competition and allow for more niche overlap
b) climate - more stable allows species to be more specialised. Less harsh habitat
c) Greater productivity in tropics leads to wider resource base. Plants benefit from heat and light, heterotrophs benefit from more plants