Cycles of matter

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Cycles of matter

• Organisms need more than energy to survive
• They also need water and other nutrients
• Over 95 of all organisms are made up of just
  four elements
• Oxygen, carbon, hydrogen, and nitrogen
• Unlike the one way flow of energy, matter is
  recycled in the biosphere
• Biological systems do not use up matter, they
  transform it

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Nutrient cycles

• All of the chemical substances that an organism
  needs to live are called nutrients
• They build tissue and carry out life functions
• And they cycle through the biosphere and
  organisms
• Important nutrient cycles for life on Earth
  include
• Carbon Nitrogen
• Oxygen participates in all of these cycles

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Carbon cycle

• Carbon is found in every chemical compound of
  living organisms
• It recycles through all living organisms and the
  environment
• CO2 gas in the atmosphere is taken in by plants
  through photosynthesis to produce glucose
• Glucose is then consumed by animals and released
  back into the atmosphere through respiration
• Decomposition of plants and animals also release
  CO2 into the atmosphere

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Volcanic activity, burning forests and fossil
fuels also release CO2 into the atmosphere
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Nitrogen is found in all amino acids which are
used to build proteins
The nitrogen cycle involves taking in atmospheric
nitrogen by nitrifying bacteria
They live on the roots of plants and convert
nitrogen gas into a nitrogen compound called
ammonia Bacteria then get food from the
roots (Mutualism)
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Nitrogen fixation

• The plants that house nitrifying bacteria are
  called legume plants
• The process of fixing nitrogen gas into ammonia
  is called nitrogen fixation
• Other bacteria in the soil convert ammonia into
  nitrates and nitrites that producer plants can
  use to make proteins
• Animals then eat the producers and reuse the
  nitrogen to make their own proteins
• When organisms die, decomposers return nitrogen
  back to the soil to be taken up by plants again
• Some bacteria convert nitrogen back into nitrogen
  gas in a process called de-nitrification

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Bacteria

• Bacteria are great at adapting
• It takes thousands of years for animals to change
  and adapt
• Bacteria take a short amount of time due to the
  fact that they reproduce rapidly
• They also exchange important information with
  each other
• For example, E. coli and antibiotics

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Limiting factors

• A limiting factor refers to anything that is
  required by a species for survival which
  decreases or becomes absent in a habitat.
• When particular needs are not met, they start to
  die off or they may not be able to reproduce.
• Some common examples of limiting factors are
  food, water, predation, water, shelter, oxygen,
  and chemicals.
• The limiting factor works as a control that
  prevents unchecked growth in a population or can
  be one that causes a population to decline and
  disappear from a habitat.
• Most of the time, a limiting factor is beneficial
  to an ecosystem.
• For example, a limiting factor that controls one
  species, such as a predator, can benefit another,
  such as its prey.
• If the predatory species were not controlled by a
  particular limiting factor, then the prey species
  would severely decrease.

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Ecological succession

• Ecosystems and communities are always changing in
  response to changes in the environment
• As an ecosystem changes, older inhabitants will
  die
• New organisms move in
• Causes further changes in the community
• Overall, the number of species and population
  sizes both increase
• Constant change will provide stability
• It is called ecological succession

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Primary succession occurs in an area where no
soil exists on the surface and begins with bare
rock
Caused by volcano eruptions or glaciations
pioneer species such as lichens break down the
rocks to begin to make soil
Then new plants can grow and take over
This process is slow and can take many years
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Secondary succession occurs when an existing
community disturbs plant life without removing
the soil
Occurs after land has been cleared after
wildfires burn woodlands, floods, tornadoes,
hurricanes
The disruptive event causes only the plant life
above ground to stop growing. Underground plants
and seeds that have not sprouted above the
ground's surface are often preserved.
Secondary succession happens much faster than
primary succession