Stages of anaerobic digestion

1. Reduction of O2 2. Reduction of NO-3 3. Reduction of Mn 4+ -> Mn 2+ 4. Reduction of Fe 3+ -> Fe 2+ 5. Reduction of SO4(2-) ->H2S 6. Reduction of CO2 -> CH4

Chemical composition of waterbodies are mediated by livng things

What are key elements for life?

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous

Decomposition is synonymous with...

ammonification

Inorganic N forms

NH3, NH4 & NO3

Typical concentrations of inorganic N in headwater streams

NH3= 0.05 ppm NH4 = 0.02 ppm

What controls how fast nutrients move through streams?

Velocity Depth SA:Volume

Phycology

Study of algae

Cyanobacteria

Prokaryotic algae that thrive off of Phosphorous. Can produce harmful toxins.

Excess algae

Redfield Ratio

106:16:1 found in marine phytoplankton C:N:P

Why do beavers build dams?

For safety and ample food opportunities

Beaver dam effects

- slows down and spreads out water - traps sediment - increase regional GW levels - releases inorganic N (NO3 or NH4) - accumulation in sediment - more anoxic conditions w/sediment

NO3 is more likely to travel furthest

When do diatoms bloom?

Spring & late summer (w/silica blooms)

Clinograde

Stratified oxygen. Below is deficient.

Redox [potential]

Capacity of solution to supply electrons. - more positive => more oxidized - more negative => more reduced

Oxidizing agent

Chemical can take/steal electrons

Reducing agent

Chemical can donate/supple electrons

Redox affects...

availability of biologically important elements and alters metabolic rates (ie proton gradients)