CH 7 Wetlands

What is the Standard Gibbs Free Energy

ΔG⸰=-nFΔE

n = number of electrons

F = Faraday’s constants (96,485) Coulombs/mol

ΔE = Difference in electrical potential, between the oxidation and reduction rxns

What happens in CH4 production in soils if the temperature of the soil increases?

CH4 concentration increases

Which ecosystem has the highest average productivity?

Wetland

How much estimated global wetland land surface area to total land area?

2.2 - 4.2%

Why do wetland sediments have high potential for denitrification, CH4 production, and soil carbon storage?

Lack of oxygen

Wetland contributes how much % of global terrestrial productivity?

Wetlands contribute 7-15% of global terrestrial productivity and store more than half of all the soil carbon on earth

What are wetlands an important source of?

Wetlands are an important source of dissolved organic matter

How do you calculate the Residence Time of water within a wetland?

RT = Wetland Volume (V)/ Total Inputs or Outputs

What are the three categories of hydraulic soils classified in

1. Soil permanently inundated with water above the soil surface

2. Saturated soils with the water table at or just below the soil surface

3. Soil where the water table depth is always below surface

What is the peat accumulation and compaction over time?

Decomposition → Burial → Compaction

How do we determine redox potential of chemical mixture in laboratory?

Connecting redox probe to standard hydrogen electrode

What is the redox potential in soils with oxygen present?

+400 and +700mV

A very high chance of accepting electrons

What is a Sulfate Reduction?

This is when Hydrogen Sulfide reacts with Fe2+ to precipitate FeS, giving a black color to anaerobic soils

FeS can be converted to pyrite 

What was the most prevalent contaminant in Bartlett Pond?

Antimony

Higher contamination in Bass