2.4 - Biomes, Zonation And Succession

Question 1

Define biome

Answer 1

Collection of ecosystems sharing similar climate conditions

Question 2

List some types of biomes

Answer 2

Aquatic
Deserts
Forests
Grasslands
Tundras

Question 3

How does isolation affect photosynthesis

Answer 3

The greater the isolation the higher the rate of photosynthesis

Question 4

How does temperature affect the rate of photosynthesis

Answer 4

The greater the temperature the higher the rate of photosynthesis

Question 5

How does precipitation affect the rate of photosynthesis

Answer 5

The greater the precipitation the higher the rates of photosynthesis

Question 6

What can influence the distribution of biomes

Answer 6

Latitude and altitude

Question 7

State a type of biome

Answer 7

Desert

Question 8

Name 3 biomes

Answer 8

Tropical rainforest - the amazon - Brazil
Tundra - islands of artic - artic and alpine

Question 9

Describe how latitude affects isolation and temperature

Answer 9

It generally gets colder as you increase the latitude. This is because at the equator solar radiation into the earth at 90 degree angle so its is more intense as you move away from the equation the rays hit the earth at a more acute angle so are spread out over a greater surface area

Question 10

Why does a higher perceipitation to evaporation ratio result in a high p/e results and low soil fertility

Answer 10

It rains or snows al or and evaporation rates are low. Then there is leaching in the soil when soluble minerals are washed downwards

Question 11

Precipitation to evaporation ratios influence soil conditions. Explain why a low p/e results in salinisation of soil

Answer 11

Water moves upwards through the soil and evaporates from the surface. This leaves salts behind and the soil salinity increases

Question 12

LOOK AT THE TRICELLULAR MODEL

Question 13

Outline the changes that are occuign worldwide as a consequence of global climate change

Answer 13

With changes in global temperatures in the future models suggest a north/south shift in biomes relative to to the equator. Biomes will also move up slopes as on mountains. Low lying biomes e.g. mangroves may be lost due to sea level rise

Question 14

Briefly explain the ways some species are moving in response to climate change

Answer 14

Plants can only migrate very slowly as seeds are dispersed by wind or animals. Animals can migrate longer distances - they will move towards the poles where it is cooler, higher up in the mountains where it is cooler, towards the equator where it is wetter

Question 15

Summarise the limits to species movements and migration

Answer 15

There are natural obstinaos to migrantion like mountain ranges and seas and ones caused by human activities such as roads, agriculture fields and cities.

Question 16

Define zonation

Answer 16

Is the change in community along an enviromental gradient due to factors such as changes in altitude, latitude, tidal level or distance from shore/coverage by water. Tends to occur in parallel lines

Question 17

Who does temp vary with altitude

Answer 17

Temperature, decreases as altitude increases

Question 18

Who does precipitation change with altitude

Answer 18

On mountains, most rainfall is at the middle altitude and plants have to adopt

Question 19

How does soil type change with altitude

Answer 19

In warmer zones, decomposition is faster so soils are deeper and more fertile. Higher up decomposition is slow and the soil tends to be more acid

Question 20

How does interaction between species change with altitude

Answer 20

Competition may crowd out some speacies and grazing may alter plant composition

Question 21

What is meant by succession

Answer 21

Is the process of change over time in an ecosystem involving pioneer, immediate and climax communities

Question 22

Distinguish between primary and secondary succession

Answer 22

Primary succession occurs on bare ground where soil formation starts the process
Secondary succession occurs where soil has already been formed but the vegetation has been removed.

Question 23

When might primary succession occurs

Answer 23

New land is created or uncovered

Question 24

What is a circumstance when secondary succession might occur

Answer 24

Established community destroyed fire, flood …

Question 25

Describe the change in both NPP and GPP that occur throughout succession

Answer 25

Early stages : low gpp but high percentage NPP
Middle stages : high gpp, lower NPP
Later stages : high gpp, NPP reaches zero

Question 26

Explain the changes in both NPP and gpp that occur through succession

Answer 26

In the early stages the Gpp is low because of the law density of producers duc to lack of soil water and nutrients.. The Npp is high as the portion of energy lost during community respiration is low. (the elcosystem is growing and biomass is accumulating)

Question 27

The specific climax community that is formed from succession will vary. Explain why this is.

Answer 27

In a climax community there are continuing inputs and outputs of matter and energy but the system as a whole is in more or less steady state equilibrium, This equilibrum will vary depending on the climatic factors, propertics of the local soil and a range of random events.

Question 28

List the ways in which humans can disrupt the process of succession.

Answer 28

Agriculture, hunting, forest vlearing, burning and grazing - all divert the progression of succession b an alternative stable state - onginal llimax hot reached

Question 29

When succession is disrupted, the system may recover quickly or slowly from the disruption, depending on its resilience. Explain what is meant by ecosystem resilience.

Answer 29

The ability of a system to retum jo its inial state after a disturbance.
The mae complex and diverse an ecosystem, the more resilient it will be as there are more interauhons behween diflerent speues.

Question 30

LOOK AT THE STAGES OF PRIMARY SUCCESSION