Week 10 - Biogeography II

Question 1

How does biogeography relate to geography?

Answer 1

Geography: Why what is where.
Biogeography: Where species are and why they are there.

Question 2

What is endemism?

Answer 2

Being unique as a species within a certain geographical area.

Question 3

What is the difference between being endemic and indigenous or native?

Answer 3

Indigenous or native species are found in a given area, but may also occur elsewhere.

Question 4

What are some areas with high endemism?

Answer 4

Madagascar, Hawaii, New Caledonia, Lake Baikal, the Galapagos Islands.

Question 5

What are five barriers that contribute to endemism?

Answer 5

Islands, mountain ranges, rivers, transition to desert, or another biome

Question 6

What are some factors that limit what kind of species can be found on or around mountains?

Answer 6

Terrain, wind, life zones, etc.

Question 7

What are some causes of species distribution?

Answer 7

Climates; soil; predators, prey, and symbionts; and other species that provide habitats.

Question 8

Which soil factors can affect species distribution?

Answer 8

Minerals, moisture, precipitation, evaporation (controlled by wind and insolation), and erosion.

Question 9

Which temperature factors can affect species distribution?

Answer 9

Extremes, averages, seasonality, duration, diurnal differences.

Question 10

Where do plant species obtain nutrients from?

Answer 10

The soil.

Question 11

What abiotic factors in regards to the soil may affect species distribution?

Answer 11

Abiotic factors such as pH, nitrogen and phosphorus content, soil grain size may limit range

Question 12

What climate factors can affect species distribution?

Answer 12

Temperature, humidity, wind velocity, and sunlight.

Question 13

How does wind velocity affect species distribution?

Answer 13

It affects evaporation, seed distribution, and the way plants grow.

Question 14

What factor of sunlight is important in regards to species distribution?

Answer 14

Photoperiod, which is affected by latitude and altitude.

Question 15

Which topography factors can affect species distribution?

Answer 15

Slope, altitude, and aspect (direction of slope).

Question 16

What is a cosmopolitan species?

Answer 16

A species that occurs wherever that environment occurs.

Question 17

Give examples of cosmopolitan species.

Answer 17

Humans, cats, krill, rats, blue whales.

Question 18

Why are only a few species considered cosmopolitan?

Answer 18

Because most species only occur on one continent.

Question 19

How does a species become cosmopolitan?

Answer 19

Two ways:

1. Broad range of environmental tolerances
2. Rapid dispersal compared to the time needed for evolution

Question 20

What are the two main camps for why species occur where they do?

Answer 20

Environmental and historical

Question 21

What are some historical reasons for species distribution?

Answer 21

continental drift, sea level changes, and glaciations

Question 22

What is niche theory concerned with?

Answer 22

Environmental causes for species distribution.

Question 23

What do we assume about “where they ain’t” in niche theory?

Answer 23

We assume that “where they ain’t” is a random distribution.

Question 24

How does niche theory work?

Answer 24

It’s the process of using computer algorithms to predict the distribution of species in geographic space on the basis of a mathematical representation of their known distribution in environmental space (= realized ecological niche).

Question 25

How does the WWF define an ecoregion?

Answer 25

A large unit of land or water containing a geographically distinct assemblage of species, natural communities, and environmental conditions

Question 26

What is the definition of an ecoregion?

Answer 26

There is no simple, single way to define them.

Question 27

What is the difference between a bioregion and a biome?

Answer 27

Although they are both continental, a bioregion is historical whereas a biome is environmental.

Question 28

What is the difference between an ecoregion and an ecosystem?

Answer 28

An ecosystem is a small area whereas an ecoregion is a larger area--a region.

Question 29

What is an ecotone?

Answer 29

A transition zone between two biomes; the borders of biomes are not sharply defined, and they tend to merge from one to the other; these areas of murky definition are called ecotones.

Question 30

Most _______ are quite variable with _______ that are different from the _______ in which they’re located.

Answer 30

Most ecoregions are quite variable with ecosystems that are different from the biome in which they’re located.

Question 31

In layman terms, how does niche theory work?

Answer 31

After determining what combination of environmental factors a species is likely to occur under, we can then plop that info onto a geographical space to try and determine where a species might occur.

Question 32

What is an example of niche theory in practice?

Answer 32

New Zealand placing endangered birds on islands that are suitable, though not native to the birds; modelling fauna distribution under global climate change scenarios; modelling the geography of species invasion.