Nutrient Cycling

STANDARD

Ecological Niches

Energy Transfer

Nutrient Cycling

Standard Level

Nutrient Cycles Biomass Carbon Cycle Carbon Fluxes Combustion Keeling Curve

SL Content Statements

C4.2.15

Primary production as accumulation of carbon compounds in biomass by autotrophs
The units should be mass (of carbon) per unit area per unit time and are usually g m−2 yr−1. Students should understand that biomes vary in their capacity to accumulate biomass. Biomass accumulates when autotrophs and heterotrophs grow or reproduce.
C4.2.16

Secondary production as accumulation of carbon compounds in biomass by heterotrophs
Students should understand that, due to loss of biomass when carbon compounds are converted to carbon dioxide and water in cell respiration, secondary production is lower than primary production in an ecosystem.
C4.2.17

Constructing carbon cycle diagrams
Students should illustrate with a diagram how carbon is recycled in ecosystems by photosynthesis, feeding and respiration.
C4.2.18

Ecosystems as carbon sinks and carbon sources
If photosynthesis exceeds respiration there is a net uptake of carbon dioxide and if respiration exceeds photosynthesis there is a net release of carbon dioxide.
C4.2.19

Release of carbon dioxide into the atmosphere during combustion of biomass, peat, coal, oil and natural gas
Students should appreciate that these carbon sinks vary in date of formation and that combustion following lightning strikes sometimes happens naturally but that human activities have greatly increased combustion rates.
C4.2.20

Analysis of the Keeling Curve in terms of photosynthesis, respiration and combustion
Include analysis of both the annual fluctuations and the long-term trend.
C4.2.21

Dependence of aerobic respiration on atmospheric oxygen produced by photosynthesis, and of photosynthesis on atmospheric carbon dioxide produced by respiration
The fluxes involved per year are huge, so this is a major interaction between autotrophs and heterotrophs.
C4.2.22

Recycling of all chemical elements required by living organisms in ecosystems
Students should appreciate that all elements used by living organisms, not just carbon, are recycled and that decomposers play a key role. Students are not required to know details of the nitrogen cycle and other nutrient cycles.

Nutrient Cycles Biomass Carbon Cycle Carbon Fluxes Combustion Keeling Curve

Nutrient Cycling

Standard Level

SL Content Statements

C4.2.15

Primary production as accumulation of carbon compounds in biomass by autotrophs

The units should be mass (of carbon) per unit area per unit time and are usually g m−2 yr−1. Students should understand that biomes vary in their capacity to accumulate biomass. Biomass accumulates when autotrophs and heterotrophs grow or reproduce.

C4.2.16

Secondary production as accumulation of carbon compounds in biomass by heterotrophs

Students should understand that, due to loss of biomass when carbon compounds are converted to carbon dioxide and water in cell respiration, secondary production is lower than primary production in an ecosystem.

C4.2.17

Constructing carbon cycle diagrams

Students should illustrate with a diagram how carbon is recycled in ecosystems by photosynthesis, feeding and respiration.

C4.2.18

Ecosystems as carbon sinks and carbon sources

If photosynthesis exceeds respiration there is a net uptake of carbon dioxide and if respiration exceeds photosynthesis there is a net release of carbon dioxide.

C4.2.19

Release of carbon dioxide into the atmosphere during combustion of biomass, peat, coal, oil and natural gas

Students should appreciate that these carbon sinks vary in date of formation and that combustion following lightning strikes sometimes happens naturally but that human activities have greatly increased combustion rates.

C4.2.20

Analysis of the Keeling Curve in terms of photosynthesis, respiration and combustion

Include analysis of both the annual fluctuations and the long-term trend.

C4.2.21

Dependence of aerobic respiration on atmospheric oxygen produced by photosynthesis, and of photosynthesis on atmospheric carbon dioxide produced by respiration

The fluxes involved per year are huge, so this is a major interaction between autotrophs and heterotrophs.

C4.2.22

Recycling of all chemical elements required by living organisms in ecosystems

Students should appreciate that all elements used by living organisms, not just carbon, are recycled and that decomposers play a key role. Students are not required to know details of the nitrogen cycle and other nutrient cycles.