Lecture 33: Macroecology

Question 1

What is the goal of macroecology?

Answer 1

Explain patterns of species diversity and abundance at larger spacial scales - that takes a top-down approach

Question 2

Explain ecological niche modelling

Answer 2

A way to explore and recreate the relationships between species and environments - focused on realized niches

Question 3

What are the two types of data you need for an ENM?

Answer 3

1. info on the realized niche
2. distribution of geographic range of concern

Question 4

What is the result of combining the two types of data for ENM?

Answer 4

You can project the potential distribution of a species in the geographic region of concern

Question 5

What other factors can ENM predict?

Answer 5

• areas with rare species
• predict immigration and extinction under future environmental conditions

Question 6

What is considered an island?

Answer 6

Any portion of isolated habitat: mountain tops, lakes, and habitat fragments

Question 7

What are patterns found on islands

Answer 7

• species richness increases with island area
• species richness decreases with island isolation

Question 8

Why is there a relationship between area and species richness?

Answer 8

Larger areas have more resources, can support larger populations, less vulnerable to extinction, and have greater niche diversity

Question 9

What is the equilibrium model of Island Biogeography?

Answer 9

Predicts that the number of species is dependent on extinction and immigration

Question 10

EMoIB: What determines immigration rate?

Answer 10

Distance of island:

low isolation: high immigration
high isolation: low immigration

Question 11

EMoIB: What determines extinction rate?

Answer 11

Island size:

large island: low extinction
small island: high extinction

Question 12

EMoIB: where is turnover the highest?

Answer 12

Islands that are small, but near the mainland - high immigration and extinction

Question 13

EMoIB: where is turnover the lowest?

Answer 13

large islands and far from the mainland - low immigration and extinction

Question 14

Explain latitudinal gradients in species richness

Answer 14

• species richness increases when you move from high latitudes to towards the equator

Question 15

What are the exceptions to latitudinal gradients

Answer 15

• ichneumonid wasps
• sea birds

Question 16

Why are the tropics more diverse?

Answer 16

1. high species diversification rate
2. evolutionary time is faster
3. higher productivity leading to more resources