Agriculture and Pesticides

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Limnology

• Ecology of freshwaters
• Lakes, rivers, and streams

rivers, and streams
Lakes are born by catastrophe
age
, and quietly die
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Rivers are ancient
Limnology
Rivers carry sediment
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Rivers are ancient
Limnology

Rivers carry sediment
meander
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A river creates its valley
Limnology
Rivers are ancient

Rivers carry sediment
meander
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Estuaries
Limnology

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Lakes rivers differ in food chains
Limnology
Lakes support photosynthetic chains
phytoplankton
Energy is autochthonous
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Lakes rivers differ in food chains
Limnology
Rivers support a detritus food chain
Energy is allochthonous
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Limnology
in temperature
Lakes are stratified
a summer lake
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Limnology
in temperature
Lakes are stratified
a summer lake
epilimnion mixes
hypolimnion stagnates
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Limnology
Lakes are stratified
by light
a summer lake
photosynthesis
detritus
decomposition
nutrient rich sediment
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Limnology
Lakes are stratified
There are 2 lakes
during warm

a summer lake
months
productive epilimnion
detritus food chain releasing nutrients
phytoplankton starved for nutrients
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In the fall
Limnology
surface water cools
40 C water sinks
phytoplankton blooms
fall turnover
nutrients returned
to epilimnion
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In the fall
Limnology
surface water cools
40 C water sinks
phytoplankton blooms
fall turnover
nutrients returned
to epilimnion
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In the winter
Limnology
lake is sealed
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In the spring
Limnology
spring turnover
nutrients mixed into epilimnion
phytoplankton bloom
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Lake food chain
Limnology
nekton
zooplankton
phytoplankton
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Zooplankton migration
Limnology
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Limnology
The Lake as a Microcosm -- Steven J. Forbes
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Limnology
An ecosystem united
seasonally