Biosphere- Biogeography

Question 1

Biogeography definition

Answer 1

Is the science that attempts to document and understand spatial patterns of biological diversity

Question 2

Factors affecting the distribution of species

Answer 2

Climate
Topography
Interactions with other species
Humans

Question 3

What are biomes

Answer 3

Places with similar climate and abiotic conditions eg similar topography

Question 4

Climatic variables that control biome distribution

Answer 4

Air temperature
Net radiation
Precipitation

Question 5

What are bioclimatic variables derived from

Answer 5

Monthly temperature and rainfall values so are more important than climatic variables

Question 6

Give 3 examples of factors controlling biome distribution

Answer 6

Run off
Soil moisture
Precipitation minus evaporation

Question 7

Seasonality increases with..

Answer 7

Distance from sea

Latitude (eg in tropics there is low range of seasonality- temp stays same all year)

Question 8

What is PAR (a bioclimatic variable)

Answer 8

Photosynthetically active radiation. PAR 0 means a plant can photosynthesise (it is warm enough)

Question 9

Theory of island biogeography

Answer 9

Kill all animals on the island
Allow island to be re colonised
Number of species reaches a predictable equilibrium

Question 10

Species richness of an island depends on its..

Answer 10

Size and location (how close it is to the mainland)

Question 11

What is the ‘rescue effect’

Answer 11

If an island is close to the mainland there is less chance of extinction as species can come to the rescue

Question 12

Does the number of species increase or decrease with latitude

Answer 12

Decrease (number of species peaks at low latitudes)

Question 13

Hypotheses to explain high diversity in the tropics - give 3 examples

Answer 13

Area
Age
Productivity 
Climate
Dispersal rates (local adaptation)

Question 14

Why are there more species in the tropics

Answer 14

Speciation rates are high

Extinction rates are low