Climate and Life on Earth I: The terrestrial biosphere

Question 1

At the global scale, variations in climatic factors, especially temperature and rainfall, determine

Answer 1

the distribution and diversity of the major terrestrial ‘biomes’, alongside their primary
productivity

Question 2

Describe some of the local conditions and resources that vary within biomes

Answer 2

• topography
• geology
• soil
• influence community patterns and productivity at a smaller scale
• change on a variety of timescales (ecological succession progresses, climate change), tracked by changes in their associated ecological communities.

Question 3

List some biomes

Answer 3

• ice sheet and polar desert
• tundra
• taiga
• temperate broadleaf forest
• temperate steppe
• subtropical rainforest
• Mediterranean vegetation
• monsoon forest
• arid deser
• xeric shrubland
• dry steppe
• semiarid desert
• grass savanna
• tree savanna
• subtropical and tropical dry forest
• tropical rainforest
• alpine tundra
• montane forests

Question 4

primary productivity

Answer 4

• the rate at which biomass is produced per unit area/volume through photosynthesis
• measured in a rate of energy production per unit area, or as a mass of carbon or dry organic matter
• paralogue of the extent to which biomes capture carbon from atmosphere

Question 5

What determines the distribution and characteristics of ecological communities at a global scale?

Answer 5

• climate (temperature)
• precipitation
• biomes

Question 6

biomes

Answer 6

zones dominated by plants with characteristic shapes, forms and physiological processes

Question 7

Describe the Whittaker Biome Classification

Answer 7

distribution of terrestrial biomes can be explained largely by temperature and rainfall

Question 8

Give some Mediterranean biomes

Answer 8

• “Garrigue”, S. France
• “Chapparal”, California
• “Fynbos”, South Africa

Question 9

Describe the meso-scale changes with elevation (and aspect)

Answer 9

• civilisation up to 1800m and 35 degrees
• rainforest up to 3000m and 25 degrees
• moorlands up to 4000m and 20 degrees
• alpine desert up to 5000m and 15 degrees
• eternal ice above 5000m and up to -25 degrees
• e.g. Mt. Kilimanjaro, Tanzania

Question 10

Categorise civilisation

Answer 10

• villages
• agriculture
• livestock breeding
• plantations

Question 11

Categorise rainforest

Answer 11

• dense vegetation
• frequent rainfall

Question 12

Categorise moorland

Answer 12

• grasslands
• upland moors

Question 13

Categorise alpine deser

Answer 13

• stone
• lava desert

Question 14

Categorise eternal ice

Answer 14

• ice
• glacier

Question 15

Ecosystems depend upon

Answer 15

the energy that is being harvested by plants, algae, and other primary producers

Question 16

Gross primary productivity (GPP)

Answer 16

• total fixation of energy by photosynthesis
• some GPP will be respired by autotroph, and lost from the ecosystem as respiratory heat

Question 17

Net primary productivity (NPP)

Answer 17

• energy fixed by photosynthesis not lost to ecosystem as respiratory heat
• all NPP passes through a live consumer system or a decomposer system

Question 18

secondary productivity

Answer 18

heterotrophs produce biomass

Question 19

Different biomes have

Answer 19

differing annual NPPs

Question 20

List some marine NPPs

Answer 20

• trade winds domain (tropical and subtropical): 13.0
• westerly winds domain (temperate): 16.3
• polar domain: 6.4
• coastal domain: 10.7
• salt marshes, estuaries and macrophytes: 1.2
• coral reefs: 0.7

Question 21

List some terrestrial NPPs

Answer 21

• tropical rainforests: 17.8
• broadleaf deciduous forests: 1.5
• mixed broadleaf and needleleaf forests: 3.1
• needleleaf evergreen forests: 3.1
• needleleaf deciduous forest: 1.4
• savannas: 16.8
• perennial grasslands: 2.4
• broadleaf shrubs with bare soil: 1.0
• tundra: 0.5-0.8
• desert: 8.0
• cultivation: 56.4

Question 22

Which is the marine biome with the lowest NPP

Answer 22

coral reefs

Question 23

Which is the marine biome with the highest NPP

Answer 23

Westerly winds domain (temperate)

Question 24

Which is the terrestrial biome with the lowest NPP

Answer 24

tundra

Question 25

Which is the terrestrial biome with the highest NPP

Answer 25

cultivation, the tropical rainforests

Question 26

Give a measure of the human domination of the biosphere

Answer 26

appropriation of NPP

Question 27

Describe human appropriation of potential NPP

Answer 27

- 23.8% - 53% from harvesting - 40% by land-use-induced productivity changes - 7% by human-induced fires

Question 28

In terrestrial systems, NPP is primarily limited by:

Answer 28

- intensity of solar radiation received - availability of water - temperature - availability of nutrients

Question 29

Different regions of the planet receive

Answer 29

different amounts of solar radiation

Question 30

Give some regions of the planet

Answer 30

- artic circle - tropic of Cancer - equator - tropic of Capricorn - antarctic circle

Question 31

Plants living in different regions have

Answer 31

- differing degrees of efficiency in using solar radiation - other resources (water) cause these efficiencies

Question 32

Precipitation levels in a region

Answer 32

- affect NPP - e.g. tallgrass prairie

Question 33

ANPP

Answer 33

above-ground NPP

Question 34

Water use will be affected by

Answer 34

temperature

Question 35

Describe the correlation between precipitation (mm) and ANPP (gm-2)

Answer 35

- strong linear correlation - y = 0.38x + 176.83 - P = 0.0003 (significant) - r^2 = 0.62

Question 36

Describe the effects of increasing temperature

Answer 36

- photosynthesis - increases rate of evaporation - increases rate of decomposition (releases nutrients)

Question 37

Productivity is only possible when

Answer 37

plants are able to photosynthesise

Question 38

Describe the relationship between maximum ecosystem GPP (%) and day of the year in temperature, coniferous and boreal systems

Answer 38

normally distributed

Question 39

Which nutrients are usually limiting?

Answer 39

phosphorus and nitrogen

Question 40

What is a plant called if it is limited by both phosphorus and nitrogen

Answer 40

co-limited

Question 41

Describe the fate of primary producers

Answer 41

energy and nutrients captured is then consumed by heterotrophs

Question 42

Describe a trophic pyramid

Answer 42

- sun's energy captured by primary producers - herbivorous consumers - 1st level carnivorous consumers - 2nd level carnivorous consumers - 3rd level carnivorous consumers - apex carnivores - heat energy lost at each stage - matter decomposed at each stage

Question 43

List some primary producers

Answer 43

phytoplankton, seaweed

Question 44

List some herbivorous consumers

Answer 44

zooplankton, cockles

Question 45

List some 1st level carnivorous consumers

Answer 45

- juvenile stages of fish and jellyfish - small fish, crustaceans and sea stars

Question 46

List some 2nd level carnivorous consumers

Answer 46

larger fish

Question 47

List some 3rd level carnivorous consumers

Answer 47

squid

Question 48

List some top carnivores

Answer 48

shark, dolphin, albatross

Question 49

Climate plays a major role in determining

Answer 49

how different sorts of ecological communities are distributed across the globe