Midterm II Overview Flashcards
_____ enables lakes to have chemical profiles that vary through their depth
stratification
T/F
1. Oxygen regulates many other chemical constituents
2. Biological processes regulate oxygen concentration with depth, and physical processes have a minimal impact
- true
- false: physical and bio processes come together to regulate it
Denitrification=
__–> ___–> ____
NO3 –> N2O –> N2
Fe3+ reduction gives what product?
Fe2+
Sulfate reduction gives what product?
SO4 –> S2-
Does oxygen regulate the redox profile of a lake?
Yes!
Differences in redox allow iron and sulfur to regulate _____ concentrations in lakes
phosphorus
What will happen to primary productivity in a lake if there’s an increase in total phosphorus?
It will also increase
What might you find in a lake that has higher [P] relative to [N]?
high microcystin concentration
ie toxic algae bloom cause by high [P] relative to [N]
____ status is an important regulator of bio-available nitrogen
redox
T/F
Basic chemical cycles do not change in stream systems (compared to lakes)
true
However, directionality of flow must be considered, and interfaces become much more important
_____ zones are important regulators of material entering streams. What do they do?
Riparian
- nutrient/ sediment retention
- nutrient uptake
- nutrient transformations (chem/ bio)
_____ length is an indicator of the health of a given stream reach & downstream impact
spiral
hyporheic zones are the flowing water equivalent of the _____
hypolimnion
Give 3 important chemical processes that occur in the hyporheic zone
- dissolved organic carbon decomposition in the absence of production
- O2 drawdown
- nutrient transformations that are particularly important for the N cycle
