2005-2006 Ecosystems

2005-2006

Ecosystem • Community of organisms plus the abiotic

factors that exist in a certain area

2005-2006

Nutrient cycling

Decompositionconnects all trophic levels

2005-2006

Carbon cycleCO2 inatmosphere

Diffusion RespirationPhotosynthesis

Photosynthesis

Plants and algae

PlantsAnimals

Industry and home

Combustion of fuels

Animals

Carbonates in sediment

Bicarbonates

Deposition ofdead material

Depositionof deadmaterial

Fossil fuels(oil, gas, coal)

Dissolved CO2

2005-2006

Birds

Herbivores

Plants

Amino acids

CarnivoresAtmosphericnitrogen

Loss to deep sediments

Fish

Plankton withnitrogen-fixingbacteria

Nitrogen-fixingbacteria(plant roots)

Nitrogen-fixingbacteria (soil)

Denitrifyingbacteria

Death, excretion, feces

Nitrifying bacteria

Soil nitrates

Excretion

Decomposing bacteria

Ammonifying bacteria

Nitrogen cycle

2005-2006Loss to deep sediment

Rocks andminerals

Soluble soilphosphate

Plants andalgae

Plants Urine

Land animals

Precipitates

Aquaticanimals

Animal tissueand feces

Animal tissueand feces

Decomposers(bacteria andfungi)

Decomposers(bacteria andfungi)

Phosphatesin solution

Loss indrainage

Phosphorus cycle

2005-2006

What have we done!

2005-2006

Impact of ecology as a science• Ecology provides a scientific context for

evaluating environmental issues– Rachel Carson, in 1962,

in her book, Silent Spring,warned that use ofpesticides such as DDTwas causing populationdeclines in manynon-target organisms

2005-2006

Barry Commoner’s Laws of Ecology• Everything is connected to everything else• Everything must go somewhere

there is no such place as “away”• Nature knows best – technology only does so much• There is no such thing as a free lunch

Laws of Unintended Consequences

2005-2006

Acid Precipitation nitrogen oxides sulfur dioxide

• power plants• industry• transportation

2005-2006 Acid rain

2005-2006

BioMagnification

2005-2006

BioMagnification• PCBs– General Electric

manufacturing plant on Hudson River

– PCBs in sediment– striped bass nesting

areas

2005-2006

Carbon DioxideGlobal Warming

2005-2006

CO2

NOx

methane

2005-2006

Ozone Depletion

protects from UV rays

2005-2006

Ozone Depletion

2005-2006

Bad ozone vs. good ozone

2005-2006

Ozone Depletion• Loss of ozone above Antarctica