CYCLING MATERIALS WITHIN THE ECOSYSTEM

Ch. 6

Conservation of matter – matter is recycled not created or destroyed. (forms: solid, liquid, gas)

In ecosystem matter recycled b/w organisms and abiotic environment

Biogeochemical cycles

Carbon

.04% of atmosphere (as CO2) and in all life (organic matter contains carbon)

Carbon sinks (reservoirs): atmospheric carbon dioxide, dissolved CO2 in oceans, organic matter in soil, fossil fuels, some rock, calcium carbonate of ocean shelled organisms, biomass

CO2 main greenhouse gas from human activities

Carbon cycle• Geological cycle: limestone (calcium

carbonate rock) dissolves from rainwater and washes carbon to ocean. Settles on sea floor, subducted under by plate tectonics. Heat and pressure releases CO2 from rock returned by volcanic eruptions.

• Biological cycle: air/water plants via photosynthesis used as fuel in cellular respiration released in waste and decomposition

issues Changing quantities in carbon sinks Industrial revolution (~ 1850) – combustion of

fossil fuels

NAME 3 WAYS CARBON GETS RETURNED TO

THE ATMOSPHERE

Check for understanding 4 - I can explain to my peers how carbon

cycles between living and nonliving matter and how humans influence the amount of carbon in the atmosphere.

3 - I understand how carbon cycles between living and nonliving matter and how humans influence the amount of carbon in the atmosphere.

2 - I understand how carbon cycles but I need more practice

1 - I am lost about the carbon cycle

NITROGEN 78% atm. Commonly a limiting factor Atm. Nitrogen (N2) gets “fixed” into ammonia by

bacteria in absence of oxygen. Ex: Rhizobium Nitrogen Fixation

Nitrification: Ammonia (NH3) nitrite (NO2-)

nitrate (NO3-)

Plants assimilate nitrogen (various forms) consumers. Living things use it for DNA and protein

Ammonification: Waste/dead body decompose back to ammonia (NH3)

Denitrification: nitrate (NO3-) atm. Nitrogen (N2);

Issues

Fertilizers into water ecosystems = algal growth

eutrophication N2O: Greenhouse gas N2O:Destroy ozone

Combustion of fossil fuels releases nitrogen and changes atm. N2 into nitrogen oxides. (NO) Photochemical smog injures plant tissues, resp.

problems, irritate eyes React with H2O to form nitric acid (HNO3) acid

deposition –decreased surface water/soil pH (effects discussed later)

Check for understanding 4 - I can explain to my peers how nitrogen

cycles between living and nonliving matter and how humans influence the amount of nitrogen in the atmosphere and in aquatic biomes.

3 - I understand how nitrogen cycles between living and nonliving matter and how humans influence the amount of nitrogen in the atmosphere and in aquatic biomes.

2 - I understand how nitrogen cycles but I need more practice

1 - I am lost about the nitrogen cycle

PHOSPHORUS

Not in atmosphere Eroded from rocks by water plants

consumers; decomposers return it to soil Other sinks: ocean floor sediment

issues

Phosphate lost from land Farm soil loses phosphate b/c plants

shipped away. Then need phosphate fertilizer for plant growth.

Washed down toilets and exit as effluent into water ecosystems.

My house

SULFUR Tiny bit in atmosphere ; part of proteins;

bacteria imp. in cycle Major sinks: sedimentary rock and oceans A little: Soil plants animals

issues Sulfur dioxide/acid deposition:

Burning coal releases Smelting of copper, lead, zinc

Improvements: scrubbers on smokestacks

HYDROLOGIC CYCLE 97% seawater; most fresh is frozen Key terms: transpiration, watershed, runoff

issues Dams Aquifer depletion

Check for understanding 4 - I can explain to my peers how water, phosphorus,

and sulfur cycle between living and nonliving matter and how humans influence the amount of these elements in the atmosphere, on land, and in aquatic biomes.

3 - I understand how water, phosphorus, and sulfur cycle between living and nonliving matter and how humans influence the amount of these elements in the atmosphere, on land, and in aquatic biomes

2 - I understand how water, phosphorus, and sulfur cycle, but I need more practice.

1 - I am lost about at least of the cycles – water, sulfur, phosphorus.