Ecology Nutrient Cycles ppt

heehawultraMechanics

Feb 22, 2014 (3 years and 3 months ago)

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The Biological
I
mportance of Carbon,
Nitrogen, Phosphorus and Water


Carbon, Nitrogen, and Phosphorus are essential
elements for all living things on earth. Without a
supply of these elements, living things would not be
able to sustain life.


Water is the molecule that all living things use to
transport nutrients and provide dissolved materials to
all cells.


These nutrients cycle from the



abiotic

to the
biotic

components



of ecosystems and back again.

The Water Cycle


Water is essential to all organisms


97% of the biosphere’s water is contained in the oceans,
2% is in glaciers and polar ice caps, and 1% is in lakes,
rivers, and groundwater


Water moves by the processes of evaporation,
transpiration, condensation, precipitation, and
movement through surface and groundwater

Water Cycle Terms to Know:


Precipitation: Water condensing into droplets and
falling from clouds to the earth’s surface


Evaporation: Water turning from liquid to water vapor
and rising into clouds


T
ranspiration: Water evaporating from the surface of
leaves


Condensation: Water vapor cools and forms liquid
water droplets


Filtration: The movement of water from the surface of
the Earth downward into groundwater reserves

The Carbon Cycle


Carbon
-
based organic molecules are essential to all
organisms


Carbon reservoirs include fossil fuels, soils and
sediments, solutes in oceans, plant and animal biomass,
and the atmosphere


CO
2

is taken up and released through photosynthesis
and respiration; additionally, volcanoes and the burning
of fossil fuels contribute CO
2

to the atmosphere

The Carbon Cycle

Carbon Cycle Terms to Know:


Photosynthesis: The process of taking CO2 from the
environment and converting it into sugars by using energy
from sunlight


Cellular Respiration: The process of breaking down sugars
to release energy for cells, releasing CO2 into the
environment


Decomposition: The breakdown of dead organisms by
bacteria and fungi to release nutrients into the
environment


Combustion: The burning of carbon
-
based compounds
such as wood and fossil fuels to get energy, releases CO2
into the environment

The Nitrogen
Cycle


Nitrogen is a component of amino acids, proteins, and
nucleic acids


The main reservoir of nitrogen is the atmosphere (N
2
),


This nitrogen (N2) must
be converted to NH
4
+

or NO
3


for uptake by
plants.

Bacteria in the Nitrogen Cycle


The main organisms involved in this cycle are different
kinds of bacteria.


The most important are called Nitrogen
-
Fixing
Bacteria.


Nitrogen
-
fixing bacteria



live
in nodules in the



roots
of legumes (plants



such
as alfalfa, soybeans,



and
peanuts)


The Nitrogen Cycle

Nitrogen Cycle Terms to Know:


Nitrogen Fixation: The process that converts
atmospheric nitrogen (N2) into NH3
(by bacteria!)


Ammonification: In the soil, NH3 is converted to
ammonia, NH4+
(by bacteria!)


Nitrification: NH4+ is converted to nitrate, NO2
-
(by
bacteria!)


Assimilation: NH4+ and NO2
-

are taken up by plants
and used to build plants’ tissues; animals which eat
plants can then get nitrogen for their bodies.


Denitrification
: NO2
-

is converted back to
atmospheric nitrogen, N2
(by bacteria!)

The Phosphorus Cycle


Phosphorus is a major constituent of nucleic acids,
phospholipids, and ATP


Phosphate (PO
4
3

) is the most important inorganic form
of phosphorus


The largest reservoirs are sedimentary rocks of marine
origin, the oceans, and organisms


S
oil is the main place where



living things on Earth get



phosphorus.

The Phosphorus
Cycle

Phosphorus Cycle Terms to Know:


Geologic Uplift: By tectonic processes, rock beneath
Earth’s surface is brought up to the surface

usually by
earthquakes and volcanoes


Sedimentation: Materials dissolved in water settle to
the bottom of the ocean and eventually become rocks


Detritus: Dead plants and animals which are
decomposed by bacteria and fungi


Weathering: Rocks on Earth’s surface are broken down
by wind and water to form soil