2.1.7 - carbon stores in different biomes

How much carbon is estimated to be in the terrestrial biosphere

3000 GtC

What is an ecosystem

A community of plant and animals who’s lives are closely linked to each other and the climate and soil of the area

What is a biome

A large naturally occurring community of flora and fauna occupying a major habitat

What is net primary productivity (NPP)

The dry weight of biomass added per unit area per year or the total amount of biomass in one location

Where are TRFs located

• between the tropics

• Biggest ones are concentrated along the equator e.g. South America

Where are temperate grasslands located

• they can be between 60N of the equator and 30S of the equator

How much more NPP is in rainforests than in temperate grasslands

3x

How much more total carbon does TRFs have compared to temperate grasslands

4x

What are the 3 factors that influence carbon storage

• temperature

• Light

• Precipitation

How does temperature affect carbon storage in the TRF

the temperature stays between 25 and 30 all year round so they have little season variation which means plants don’t die and can store more carbon

How does temperature affect carbon storage in the temperate grasslands

The temperature ranges from -30 to 40 which means that in winter many plants and animals die and so less carbon is stored and biomass is lost

How does precipitation affect carbon storage in TRF

• They have over 2000mm of annual rainfall which can lead to leeching which is where the soil at the top which stores carbon is washed away

• It also means plants won’t die and can store carbon all year

How does precipitation affect carbon storage in the temperate grasslands

They have 500mm or less which could lead to drought and so loss of flora and fauna a which means less carbon is stored

How does light affect carbon storage in a TRF

There are high levels of solar radiation which allows for higher rates of photosynthesis and therefore more carbon storage as they absorb it

How does light affect carbon storage in a temperate grasslands

In the summer they have much longer days but in the winter they have shorter days so it evens out overall

How many GtC is stored in biomass and soil in a temperate grassland

185

How many GtC is stored in biomass and soil in a TRF

550

What is a Gerschmel diagram

Where is leeching most common

In a TRF as they have more and heavier rainfall

Where do TRFs have most carbon stored

In its biomass

Where do temperate grasslands have most of the carbon stored

In the soil

What is the total biomass on earth

545.8 gigatons

What % of biomass does plants make up

86.4

What % of biomass does Bacteria make up

12.8

What % of biomass does Animals make up

0.79

What % of biomass does Humans make up

0.01

What is deforestation

The large scale clearing or thinning of forests by humans

Why is deforestation increasing

Due to agricultural expansion and rising demand for food and commodities

Where does deforestation mainly happen

In the Amazon, south east Asia and parts of Africa

How many hectares of tropical rainforest did we lose in 2025

4.3 million

What are the local effects of deforestation

• soil erosion

• Loss of habitat

• Disruption of biodiversity

• Flooding

Why are some global effects of deforestation

• climate change

• Economic impact

• Loss of biodiversity

How does deforestation affect carbon stores

It releases huge amounts of CO2 into the atmosphere which increases the amount of heat trapped by the layer of greenhouse gasses

What is afforestation

Planting new trees or plants on land that wasn’t previously forested e.g. abandoned farmland

How does afforestation link to the UN’s REDD scheme

Because they are providing funding for afforestation to happen in different countries to try and mitigate carbon emissions

How will afforestation affect climate change

It will slow it down slightly as it will decrease the amount of CO2 that is trapped in the atmosphere

What is a monoculture

An agricultural practice where only 1 crop is grown

How does a monoculture affect carbon storage

Increases carbon storage as focusing on a single species can lead to higher biomass production and so more carbon can be stored

What is carbon offsetting

The practice of compensating for greenhouse gas emissions by fundings projects that reduce remove or prevent an equivalent amount of CO2 elsewhere

How can agriculture decrease the amount of soil carbon

When used as farmland the soils natural structure is disturbed and so it stores less carbon

How can agriculture lead to land degradation degradation

Unstable farming practices such as overgrazing which can lead to soil erosion

What can happen if the soil is managed correctly

It can lead to higher levels of carbon sequestration e.g. planting hedgerows increases soil storage by 40%