Freshwater Lifezones
1. Lentic: standing water (lakes, ponds)
2. Lotic: flowing water (rivers, streams) hint: think Lo Flow
Lentic
Lake Zones:
Edge: Littoral
Top: Limnetic
Middle: Profundal
Bottom: Benthic
Summer and winter = stratified layers
Spring and fall = overturn equalizes temp. and surface D.O. brought down and bottom nutrients brought
up.
Lakes classified according to nutrient content and productivity:
Oligotrophic: poorly nourished, low NPP, clear water
Eutrophic: excessive nutrients, high NPP, murky waters
Eutrophication: natural increase of nutrients over time
Cultural Eutrophication: excessive input of nutrients due to human activities
Urban run-off (fertilizers)
Agricultural run-off (fertilizers and animal waste)
Inland wetlands: lands covered with freshwater all or part of the time (excluding lakes, reservoirs, and
streams)
Marshes
Swamps
Prairie potholes
Floodplains
Tundra summer
Legislation for wetlands:
Mitigation Banking: allows the destruction (for “development” – housing, roads, shopping malls) of
existing wetlands as long as an equal area of the same type of wetland is created or restored.
Lotic:
Rivers Zones
Start = source
Middle = transition
End = floodplain