Download Cycles of Matter in the Biosphere

Cycles of Matter in the
Biosphere
Unlike the one-way flow of energy, matter is
“recycled” in the Biosphere
(the living portion of our planet)
Ecology Standards:
6d ~ Students know how water, carbon, and nitrogen cycle
between abiotic and biotic resources as well as through
organic matter in the ecosystem and how oxygen cycles
through photosynthesis and respiration
Cycling of Matter


Elements, chemical compounds, and other
forms of matter are passed from one
organism to the next on our planet
The biogeochemical cycle is the cycle that
describes how nutrients and water are
recycled in the biosphere

The four we will cover: Water, Carbon, Nitrogen,
and Phosphorous
The Water Cycle
aka the “Hydrologic Cycle”

Terms you should know for the Water Cycle:


Evaporation – process by which liquid water is
changed into a gas
Transpiration – water evaporation through the
leaves of plants
The Water Cycle
aka the “Hydrologic Cycle”

Terms you should know for the Water Cycle:




Condensation – process by which gaseous water
forms liquid water
Precipitation – the return of water back to the Earth
(aka - rainfall)
Seepage – process where liquid water soaks or
seeps into the soil or ground becoming groundwater
Runoff – when liquid water flows down a hillside,
mountain or slope to sea level
The Water Cycle
Where do we get our Water?
How much fresh water is there?
(approximately)
The Carbon Cycle



Carbon, element 6 on the Periodic Table, is
considered the “element of life”
Carbon is found in all living organisms on Earth
The most common exchange of Carbon is
between plants and animals though there are
Four Main Ways Carbon is recycled in the
Biosphere
The Carbon Cycle

The Four ways Carbon is recycled:




Biological processes like photosynthesis & respiration
Geochemical processes such as volcanic activity
Mixed biogeochemical like dead organisms being
compressed over time forming fossil fuels
Human activities such as burning of fossil fuels,
forests, and mining
The Carbon Cycle
The Carbon Cycle
The Nitrogen Cycle

Nitrogen gas is the most abundant gas in our
atmosphere at 78%



It is a binary molecule consisting of two ‘bonded’
Nitrogen atoms (N2)
Nitrogen is an essential element in the
formation of proteins
Plants cannot absorb Nitrogen gas directly so
they need help
The Nitrogen Cycle

Bacteria is the key to making Nitrogen
available for plant use!



Bacteria in the soil convert Nitrogen gas into
Ammonia (NH3) through a process called nitrogen
fixation
Different types of bacteria convert the Ammonia into
nutrients for plants (nitrates and nitrites)
Nitrates are taken into plants where they convert
them into amino acids and proteins
The Nitrogen Cycle
The Nitrogen Cycle

A third type of
bacteria converts
the nitrates back
into atmospheric
Nitrogen (N2 gas)
in a process called
denitrification
The Phosphorus Cycle

Phosphorus, element # 15 on the Periodic
Table, is an essential element to living
organisms


Phosphorus helps to form the important molecules
DNA & RNA that contain the genetic materials
critical for all living things on the planet
Phosphorus is unique in that it does not enter
the atmosphere

It is found mainly in land sediments like rock and
ocean sediments
The Phosphorus Cycle


In rocks and minerals phosphorus exists as
inorganic phosphate and is gradually
“released” after erosion of sediments
Phosphates are absorbed by plants through
their roots and the plant binds it into organic
compounds that are passed to consumers
when they eat the plants

This is the only way that Phosphorus can enter the
biological systems!
The Phosphorus Cycle