14

Question 1

Draw and describe a general graph for the performance of species against an environmental gradient
label:
- lethal zones
- where growth occurs
- where reproduction occurs
- where survival occurs

Answer 1

species have ranges of tolerance along environmental gradients

Question 2

define the ecological niche

Answer 2

• the combination of physiological tolerances and resource requirements of a species
• more casually, a species’ place in the world - what climate it prefers what it eats, etc

Question 3

draw a graph and describe the Hutchinsonian niche

Answer 3

the niche is an ‘n-dimensional hypervolume’ shaped by the environmental conditions under which a species can ‘exist indefinitely’. Each axis is an ecological factor important to the species being considered

Question 4

factors determining biomes

Answer 4

• temperature is mostly a function of latitude
• higher latitudes colder; seasonality a function of temperature (summer-winter)
• lower latitudes warmer; seasonality a function of rainfall (dry-wet season)
• rainfall mostly depends on atmospheric circulation, offshore ocean currents, rain shadows

Question 5

Intertropical convergence

Answer 5

• shows a line of rain clouds across the pacific
• ITCZ shifts seasonally, producing rainy and dry seasons in some parts of the tropics

Question 6

how does the ITCZ form?

Answer 6

When the northeast trade winds from the Northern Hemisphere and the southeast winds from the Southern Hemisphere come together, it forces the air up into the atmosphere, forming the ITCZ.

Question 7

Coriolis effect

Answer 7

the earth’s rotation deflects winds: objects (including hurricanes) appear to be deflected eastwards as they move away from the equator and deflected westwards as they move towards the equator

Question 8

general trends of terrestrial vegetation with climatic variables

Answer 8

• vegetation growth (primary productivity) increases with moisture and temperature
• vegetation stature also increases so region with certain combinations of moisture and temperature develop predictable, characteristic types of vegetation (biomes)
• seasonality is secondarily important

Question 9

draw a Whittaker’s diagram

Question 10

—– mostly determines terrestrial biomes

Answer 10

latitude

Question 11

changes in temperature within basic latitudinal belts

Answer 11

land changes temperature more readily than water; maritime climates are moderate, continental climates are extreme; oceans provide thermal inertia

Question 12

changes in precipitation within basic latitudinal belts

Answer 12

• evaporation high from warm bodies of water, low from cold
• prevailing winds
• orographic precipitation (air forced up mountainsides undergoes cooling, precipitates on upper windward slopes)
• rain shadows created on leeward slopes of mountain ranges
• seasonality of moisture also important

Question 13

leeward slope

Answer 13

slopes that are oriented away from the wind

Question 14

draw diagram of orographic precipitation

Question 15

latitudinal patterns are complicated by

Answer 15

the distribution of landmasses

Question 16

how do ocean currents affect precipitation?

Answer 16

driest deserts occur inland of cold-water upwellings as cold water -> dry air

Question 17

when would animals’ geographical ranges not correspond to biomes (i.e. limited by climate or vegetation)

Answer 17

• transcend biomes (ecological versatility, super generalists)
• not at limits because of recent history (eg limited dispersal)
• limited by other organisms

Question 18

describe ecological niche modelling

Answer 18

• also called species distribution modelling
• uses data from a species’ present distribution to predict where a species can live
• usually relies on climate data; more rarely on other niche axes, such as resources

Question 19

what is ecological niche modelling useful for modelling for?

Answer 19

• biological invasions
• how species’ ranges may shift as climate changes
• spread of vector-borne diseases

Question 20

describe Dengue

Answer 20

a virus vectored by Aedes mosquitoes

Question 21

observed range shifts

Answer 21

• estimated that species are moving polewards
• although many factors influence a species’ range, there is considerable evidence that numerous species are moving polewards to track recent changes in climate

Question 22

Scarlet Macaw

Answer 22

temperature (x axis) precipitation (y axis)