Lecture 3 - Climate

Question 1

Why are plants adapted to adverse weather conditions?

Answer 1

Because they re unable to move away and so are adapted to conditions such as drought, flood, extreme heat etc.

Question 2

How are animals adapted to adverse conditions?

Answer 2

Via their:

• endocrine system
• metabolism
• thermoregulation

Question 3

What is the cause of latitudinal variation in solar radiation absorption?

Answer 3

Earth’s spherical shape is the cause of this.

Question 4

Name factors which affect temperature?

Answer 4

• latitude
• proportion of land and ocean
• Earth’s rotation and tilt on axis

Question 5

What creates seasons?

Answer 5

The tilt of the Earth’s axis and it’s orbit.

Question 6

What is the definition of weather?

Answer 6

Short term atmospheric conditions at a particular time and space. Short term responses from animals to weather changes.

Question 7

How does climate vary from weather?

Answer 7

Climate is an average of atmospheric conditions over a much longer period of time than weather. Longer responses by organisms to climate. Climate linked to radiation levels on earth.

Question 8

Radiation

Answer 8

• Solar radiation drives climate patterns
• around 70% absorbed by atmosphere and earths surface in form of heat
• greenhouse gases trap heat
• solar radiation determines atmospheric air circulation and precipitation patterns

Question 9

What Is the Albedo affect?

Answer 9

Darker surfaces (eg water and forests) absorb more radiation whereas lighter surfaces eg ice and snow reflect more radiation

Question 10

Why is the Northern hemisphere slightly warmer than the southern hemisphere?

Answer 10

The northern hemisphere is around 2degrees C warmer tan the southern hemisphere as land radiates more heat than ocean and the northern hemisphere has a greater proportion of land.

Question 11

How are atmospheric circulation cells created?

Answer 11

Surface air replaces rising air.

Question 12

Coriolis effect

Answer 12

How objects veer towards different directions depending on what hemisphere they’re found in.

Question 13

Where is Earth’s rotation at its fastest?

Answer 13

At the equator.

Question 14

How is a gyre formed?

Answer 14

When a prevailing wind meets a continent

Question 15

Why do the Northern and Southern hemispheres have different seasonal patterns?

Answer 15

Due to the tilt of the Earth’s axis.

Question 16

What does ocean floor topography affect?

Answer 16

1. water depth
2. light penetration
3. water temp., pressure, movement

Question 17

Adaptations to temporal variation in climate:

Answer 17

1. tolerance
2. dormancy (eg. hedgehog hibernation)
3. migration (bird migration in winter)

Question 18

Adaptations to daily variation in climate:

Answer 18

1. circadian rhythms - 24 hour cycle in physiological processes
2. response to external cues such as sunlight and temp.
   - birds sing in the morning
   - slugs active at night
   - mosquitoes bite at night

Question 19

Spatial variation within climate has 3 scales:

Answer 19

1. variation across climatic zones
2. variation within a region
3. microclimatic variation

Question 20

Give an examples of organisms which are inhibited by temperature.

Answer 20

Case study 1: the plant wild madder’s growth is closely correlated with the 4.5 degree C January isotherm. Lower temps inhibit shoot development and growth.
Case study 2: The saguaro cactus is likely to die when kept below freezing for more than 36 hours.
Case study 3: Barnacle dies in summer temps above 25 degree C.

Question 21

Give an example of an organism which has adapted to competition for radiation.

Answer 21

Case study 1: Vernal species - avoid competition for light by growing early in the season.

Question 22

How do endotherms and exotherms differ in their adaptations to changes in temperature?

Answer 22

Endotherms
- regulate temp by producing heat within their body
- which requires a large amount of energy
- eg. birds, mammals
Ectotherms
- rely on external sources of heat
- killed by extreme temps
- perform slowly at lower than optimum temps