Transcript Ch 3 The Biosphere

1. Review- By what two processes is water cycled
from land to the atmosphere
Sequence- Describe one way in which water from
Lake Superior may make one complete cycle
through the atmosphere and make it back to Lake
Superior
2. Review- Why do living organisms need nutrients
Predict- Based on your knowledge of the carbon
cycle, what do you think might happen if humans
were to continue to clear and burn vast areas of
forests for building
3. Explanation- Describe how oxygen moves
through the biosphere as part of the carbon
cycle. Include a description of the various forms
that oxygen takes.
CH 3 THE BIOSPHERE
3.4 Cycles if Matter
Biogeochemical Cycles


Elements pass from one organism to another and
among parts of the biosphere through closed loops
Powered by the flow of energy.
Biogeochemical Cycles


Involve biological processes, geological processes,
and chemical processes
Matter moves through these cycles, it is never
created or destroyed.
Biogeochemical Cycles

Biological Processes
 All
activities performed by living organisms
 Eating, breathing, “burning” food, and eliminating
waste products.
Biogeochemical Cycles

Geological Processes
 Include
volcanic eruptions, the formation and
breakdown of rock, and major movements of matter
within and below the surface of the earth.
Biogeochemical Cycles

Chemical and Physical Processes
 Include
the formation of clouds and precipitation, the
flow of running water, and the action of lightning.
Biogeochemical Cycles

Human Activity
 Include
the mining and burning of fossil fuels, the
clearing of land for building and farming, the burning
of forests, and the manufacture and use of fertilizers.
The Water Cycle


Enters atmosphere due to evaporation or
transpiration in plants
In atmosphere, water vapor condenses to form
clouds and if they become large enough will fall as
precipitation.
The Water Cycle


Precipitation can become ground water if it
absorbed into the soil or flow along the surface
until it enters a stream or lake
Ground water can enter plant’s roots, flow into
streams or lakes, or can become an underground
reservoir.
Nutrient Cycles



Carbon
Nitrogen
Phosphorous.
Carbon Cycle


Plants take in CO2 during photosynthesis and use
the carbon to build carbohydrates
Carbohydrates then pass through food webs to
consumers.
Carbon Cycle


Organisms release carbon in the form of carbon
dioxide gas by respiration
When organisms die, decomposers break down the
bodies, releasing carbon to the environment.
Carbon Cycle


Geologic forces can turn accumulated carbon into
carbon-containing rocks or fossil fuels
CO2 is released into the atmosphere by volcanic
activity or by human activities.
The Nitrogen Cycle


Need nitrogen to make amino acids (proteins) and
nucleic acids (DNA & RNA)
Nitrogen gas (N2) makes up 78 percent of Earth’s
atmosphere.
The Nitrogen Cycle

Ammonia (NH3), nitrate ions (NO3), and nitrite ions
(NO2) are found in soil, in the wastes produced by
many organisms, and in dead and decaying organic
matter.
Nitrogen Cycle

Dissolved nitrogen exists in several forms in the
ocean and other large water bodies.
Nitrogen Cycle

Nitrogen Fixation
 Bacteria
convert nitrogen gas into ammonia.
Nitrogen Cycle



Other bacteria convert ammonia into nitrates and
nitrites that producers can use
Consumers eat the producers and reuse nitrogen to
make what they need
Decomposers release nitrogen from waste and dead
organisms as ammonia, nitrates, and nitrites.
Nitrogen Cycle

Denitrification
 Bacteria
obtain energy by converting nitrates into
nitrogen gas, which is released into the atmosphere.
Nitrogen Cycle

Nitrogen Fixation
 Nitrogen
gas is converted to usable forms by lightning.
Nitrogen Cycle


Humans make and use fertilizers
Excess fertilizer is often carried into surface water
or groundwater.
The Phosphorus Cycle




Used in DNA & RNA and other molecules
Very important but not abundant
Land- Inorganic phosphate as rocks and soil
minerals
Ocean- Dissolved phosphate and sediments.
The Phosphorus Cycle

Rocks and sediments wear down, phosphate is
released
 May
soil.
stay on land and cycle between organisms and
The Phosphorus Cycle


Plants bind phosphate into organic compounds
from soil and water
Organic phosphate moves through the food web,
from producers to consumers.
The Phosphorus Cycle

Phosphate my dissolve in water and flow through
rivers to oceans and be incorporated into marine
organisms.

Limiting Nutrient
 Nutrient

whose supply limits productivity
Primary Productivity
 Rate
at which primary producers create organic
material.
Nutrient Limitation in Soil
Fertilizers contain large amounts of nitrogen,
phosphorus, and potassium
 Plants acquire carbon dioxide from the
atmosphere
 Micronutrients such
as calcium, magnesium,
sulfur, iron, and manganese
are necessary in relatively
small amounts.

Nutrient Limitation in Water

Saltwater
 Nitrogen

is often the limiting nutrient
Freshwater
 Phosphorus
is typically the limiting nutrient.
Nutrient Limitation in Water

Aquatic ecosystem can receive a large input of a
limiting nutrient
 Runoff
from heavily fertilized fields.
Nutrient Limitation in Water

Can result in “Algae blooms”
 May
not be enough consumers
 May disrupt the ecosystem.