Session 18: The Terrestrial Carbon Cycle: Soils Flashcards
5 Parts of the terrestrial process of carbon flow
- Photosynthesis, plant respiration, Run off/erosion, litter, soil respiration
What determines the amount of carbon stored above ground vs in soils?
Soil type, vegetation, Climate
What is Soil
Minerals, Organic matter,
Types of soil weathering
Physical, Chemical, Biological
O - Soil Layer
Organic Matter
A = Soil Layer
Horizon or Topsoil
- Dark
- Rich
- Abundant life
B - Soil Layer
Horizon or Subsoil
- Light
- Low organics
- Low life
C - Soil Layer
Horizon Or Parent Material
- No life
- No Organics
- Rocks
R - Soil Layer
Horizon or Bedrock
- Nothing to support life
Which part of Soil has the most Carbon?
The top one meter tends to have the most carbon
Clay
Small particals close together. Holds water and nutrients well
Loam
Mixture of Clay, Silt, Sand
Silt
Water and nutrient holding capacity is high but air content is poor
Sand
Large particles cause large air space and cant hold nutrients and water
Rainforest nutrient cycle
Trees grow, trees shed, decaying vegetation, Nutrients enter soil, Shallow roots take up nutrients.
Temperate Grassland:
Black Soils
Nutrient rich soils with deep decay branch grass roots
Northern Wetlands:
Hydric Soils
Formed after flooding conditions creating anaerobic conditions. Less effective decomposition creating a net sink of GHG
Which of the three ecosystems is the best for mitigating climate change
Wetlands because they hold the most Methane.
What happens to methane wetlands when they get hotter?
Methane is released
What does Deforestation cause in therms of Soil and plants
Loss of plant and soil carbon releasing into the environment
Why are plants and trees more effective in terms of runoff
Because they stop the water and wind from increasing runoff
Natural Ecosystem disturbances
- Forest fires
- Storm based vegetation emoval
- disease
Human ecosystem disturbances
- Land cover change
- De and reforrestation
- agriculture
- over grazing
- invasive species
- pollution
