http://www.life.uiuc.edu/animalbiology/105/http://www.life.uiuc.edu/animalbiology/105/Name: eee105Name: eee105Password: prAIRiePassword: prAIRie

Ecology of freshwaters Lakes, rivers, and streams

LimnologyLimnology

Lakes are born by catastropheage, and quietly die

rivers, and streamsrivers, and streams

LimnologyLimnologyRivers are ancientRivers carry sediment

LimnologyLimnology

Rivers are ancientRivers carry sediment

meander

LimnologyLimnology

A river creates its valley

Rivers are ancientRivers carry sediment

meander

LimnologyLimnology

Estuaries

LimnologyLimnologyLakes & rivers differ in food chainsLakes support photosynthetic chains

CO2 + water sugarsphytoplankton

Energy is autochthonous

LimnologyLimnologyLakes & rivers differ in food chainsRivers support a detritus food chain

Energy is allochthonous

LimnologyLimnology

Lakes are stratified in temperature

a summer lake

LimnologyLimnology

Lakes are stratified in temperature

wind

epilimnion mixes

hypolimnion stagnates

a summer lake

LimnologyLimnology

Lakes are stratified by light

photosynthesis

detritus

decomposition

nutrient rich sediment

a summer lake

LimnologyLimnology

Lakes are stratifiedThere are 2 lakes

productive epilimnion

detritus food chain releasing nutrients

during warm

phytoplankton starved for nutrients

a summer lake months

LimnologyLimnologyIn the fall surface water cools

40 C water sinks

fall turnover

phytoplankton blooms

nutrients returned

wind

to epilimnion

LimnologyLimnologyIn the fall surface water cools

40 C water sinks

fall turnover

phytoplankton blooms

nutrients returned

wind

to epilimnion

LimnologyLimnologyIn the winter

ice

lake is sealed

LimnologyLimnologyIn the spring

spring turnover nutrients mixed into epilimnion

phytoplankton bloom

wind

LimnologyLimnologyLake food chain

phytoplankton

zooplankton

nekton

LimnologyLimnologyZooplankton migration

LimnologyLimnology

The Lake as a Microcosm --

Steven J. Forbes

LimnologyLimnology

An ecosystem united

seasonally