Lec 31 (Macro ecology)

Question 1

What is macroecology?

Answer 1

macroecology is the large-scale

study of species abundance and distribution.

Question 2

Information about a species’ current distribution
and niche requirements can be combined with
spatial information to predict? (Ecological niche modeling)

Answer 2

invasion and range expansion.

Ecological niche modeling

Question 3

Fundamental niche vs Realized niche

Answer 3

-Physical conditions under which a species might live in the absence of interactions with other species

-Physical conditions under which a species might
live when restricted by interactions with other
species

Question 4

Three basic steps to moving from abstract niche

concept to specific locations…

Answer 4

1. Identify niche of species of concern.
2. Determine distribution of environmental
   conditions through geographic range of concern.
3. Combine information to produce map of
   potential distributions of species of concern.

This is straight-forward in principle,
but difficult in reality!

Question 5

What does Ecological niche modeling looks at?

Answer 5

Range of Tolerance

Realized and fundamental niches

Global patterns of environmental conditions

Question 6

Create a ecological niche model for Predicting the Spread of an Invasive Crab Species Throughout North America.

Answer 6

1. The mitten crab, Spread through world via
   shipping ballast water
2. Predicted distribution of mitten crab in North
   America based on levels of 12 environmental variables
3. Predicted distribution of mitten crab in North
   America when life history considered

Question 7

Why would we want to predict potential invaded areas?

Answer 7

Know where to focus monitoring programs to detect and remove the invader (stop the spread)

Question 8

What are some limitations of ecological niche

modeling?

Answer 8

• Focuses on realized niches (where the species has existed before); does not consider the fundamental niche
• Even harder to model rare species because we will have few observations from which to gather environmental data

Question 9

What are some pplications of ecological niche models? (single species)

Answer 9

• Can be used to direct researchers to areas in
which rare species may be found.

• Can highlight areas where species could move to
under future environmental conditions (e.g. changing climate).

• Predict potential invaders

Question 10

What are some applications of ecological niche models? (large scale)

Answer 10

• can examine broader patterns of diversity across large geographic scales
• Relationships between size of geographic area, isolation, and species diversity

Question 11

What is an “island”?

Answer 11

Any portion of isolated habitat (Mountain tops Lakes Land islands)

Question 12

Species Richness Patterns…

Answer 12

• Species richness increases with island area

* Species richness decreases with island isolation (distance from mainland and other islands)

Question 13

Where will there be more species, an area with more lakes or an area with less lakes?

Answer 13

-An area with more lakes because species richness increases with island size… also the more isolated an island is the less species it has

Question 14

Why are there more species in larger areas or areas with less isolation?

Answer 14

• Likely have more resources
• Can support larger populations, less vulnerable to extinction
• Have greater niche diversity (support more species richness)

Question 15

Species richness on islands increases with increasing distance of island from mainland.

True or False

Answer 15

False…

Species richness on islands DECREASES with increasing distance of island from mainland.

Question 16

How does isolation affect diversity?

Answer 16

Isolation doesn’t effect diversity

Question 17

Latitudinal Gradients in Species

Richness…

Answer 17

Species richness generally increases from middle and
high latitudes to the equator.

Most groups of organisms are more species-rich in the
tropics than they are at higher latitudes.

Question 18

Well-documented decline in species richness as one moves from ____ to _____ latitudes.

Answer 18

low to high latitudes.

Question 19

Why is species richness higher in lower latitudes

Answer 19

Time and area effects

Rate of Diversification

Question 20

TIME AND AREA EFFECTS…

Answer 20

• Tropical ecosystems are generally older and disturbed less frequently.
• Tropics include greater area of both land and water.
• Temperatures more uniform across range of tropical latitudes. (warm in low latitudes, cold in higher)

Question 21

Rate of Diversification…?

Answer 21

• increased species diversification rates in the tropics, relative to low latitudes.
• increased speciation rates, decreased extinction rates, or both.
• Speciation rate increased due to stronger biotic interactions in tropics

Question 22

BUT…Why is temperate tree species richness greatest in Asia?

Answer 22

• Evidence that most temperate tree species originated in eastern Asia.
• Fewer species in eastern North America due to dispersal limitation.
• More trees have gone extinct in Europe (unable to get to refuge during last ice age).