NUTRIENT CYCLES

GEOCHEMICAL CYCLES

Movement of a particular form of matter through the living and nonliving parts of an ecosystem

Earth is a closed system…must continually recycle essential matter

(Matter is neither created nor destroyed)

THE CARBON CYCLE

Carbon is especially important to living systems because it is the key ingredient in all living organisms…Proteins, carbohydrates, lipids, nucleic acids

PROCESSES IN THE CARBON CYCLE

Photosynthesis Respiration Decomposition of plants and

animals Conversion of biochemical

compounds

OTHER PROCESSES IN THE CARBON CYCLE

CombustionWhen wood or fossil fuels are burned, CO2 is released into the atmosphere

OTHER PROCESSES IN THE CARBON CYCLE

Weathering of carbonate rocksBones/shells fall to the bottom of

oceans/lakes & are incorporated into sedimentary rocks

When they decompose, Carbon is released into ocean, atmosphere

THE NITROGEN CYCLE

Why do we need nitrogen?Nitrogen is necessary for

organisms to make amino acids…

…which are needed to build proteins!!!

NITROGEN RESERVOIRS

In the atmosphere as elemental nitrogen (N2)78% of the air is N2 gas

In living organisms as proteins or nucleic acids

In organic materials that compose soil

PROCESSES IN THE NITROGEN CYCLE

NITROGEN FIXATION:Nitrogen fixing bacteria-found

in soil, root nodules of plantsConvert elemental nitrogen into

forms that are available for use by plants

They “fix” it for the plants

PROCESSES IN THE NITROGEN CYCLE

NITROGEN INTAKE:Plants take in nitrogen through

root systems in the form of ammonia or nitrate

This is how nitrogen enters the food chain.

PROCESSES IN THE NITROGEN CYCLE

DECOMPOSITION:When an organism dies or

animals produce waste products

Decomposers return nitrogen to the soil

PROCESSES IN THE NITROGEN CYCLE

DENITRIFICATION:Denitrifying bacteria break

down nitrogen compounds in the soil

Release elemental nitrogen into the atmosphere

“De” undo, reverse

THE WATER CYCLEAKA: THE HYDROLOGIC

CYCLEWater is a necessary substance for the life processes of all living

organisms

THE WATER CYCLEAKA: THE HYDROLOGIC CYCLE

PRECIPITATION:The process in which water (in the form of rain, snow, sleet, or hail) falls from clouds in the sky.

THE WATER CYCLEAKA: THE HYDROLOGIC CYCLE

EVAPORATION:Water changing from a liquid to a gas

TRANSPIRATION:Evaporation of water from a plant’s leaves

THE WATER CYCLEAKA: THE HYDROLOGIC CYCLE CONDENSATION:

Water vapor (a gas) in the air turns into liquid water. (Condensing water forms clouds in the sky.)

As water vapor condenses—impurities (such as dust) are removed from the atmosphere and fall to Earth with precipitation

THE WATER CYCLEAKA: THE HYDROLOGIC CYCLE

ACCUMULUATION: Water pools in large bodies

(oceans, seas and lakes). SEEPAGE:

Water entering the ground

THE WATER CYCLEAKA: THE HYDROLOGIC CYCLE RUN-OFF:

As water travels through soil and rock, it is physically filtered of impurities (filtration)

Water flow slows—heavier particles settle out and purified water continues toward oceans

THE WATER CYCLEAKA: THE HYDROLOGIC CYCLE Also remember…

Water is also returned to the environment during cellular respiration!

C6H1206 + O2 CO2 + ATP + H2O

O2-CO2 balance…plants need to produce enough O2

Oxygen produced by plants is also responsible for the ozone layer Prevents much of the Sun’s UV radiation from

reaching Earth’s surface

The story of my fish tank…

AMMONIA (NH3) is released through respiration & excretion

Ammonia is very deadly in high concentrations—so enough fish producing ammonia in a small space (like an aquarium)…will kill the fish.

Well, this doesn’t have to happen…

Bacteria present in an aquarium will feed on ammonia producing nitrites…another bacteria will feed on nitrites producing nitrates…

Nitrates are not nearly as harmful, and much, much easier to control. You would need OBSCENE amounts for it to do any real damage.