Download CH # 2E

CHAPTER 2E
Cycles in Nature…..
The Cycles of Matter…..
• The Water Cycle:
• The movement of water between the oceans,
atmosphere, land, and living things
• How Water Moves:
Evaporation – liquid to vapor
Condensation – vapor to liquid
Precipitation – rain, snow, sleet, hail
fall to the earth and
flows into streams,
rivers, lakes
• Runoff – when precipitation falls to the
ground and flows into streams, rivers, and
lakes.
• Groundwater – when precipitation seeps
into the ground and is stored
in spaces between rocks
Water and Life…..
• Without water there would be no life on
earth ! ! ! !
• Organisms are made of mostly water
• Helps transport nutrients and wastes in an
organism
• Helps regulate temperature
• ALL water is returned to nature
• Transpiration – plants release water vapor
back to the
environment
The Carbon Cycle…..
• The 2nd most common molecule in
organisms are ORGANIC molecules
• Contains CARBON
• Photosynthesis and Respiration are the basis
of the Carbon Cycle.
– Plants use carbon dioxide to make sugar
– Animals get their carbon and energy by eating
plants
– This carbon is returned to the environment
when organisms burn sugar (respiration)
» Carbon dioxide is given off
» Water vapor is given off
• Decomposition and Combustion –
breakdown of substances into simpler
molecules
• Fungus decompose organic matter and carbon
dioxide and water are returned back to the
environment
• Fire demonstrates combustion in which carbon
dioxide is released back to the environment
The Nitrogen Cycle…..
• Organisms need nitrogen to build proteins
and DNA
Converting Nitrogen Gas…..
• 78% of atmosphere is nitrogen gas
• Most organisms can’t use nitrogen directly
• Bacteria in the ground changes it into a
usable form
Passing it on…..
• When organisms die, decomposition
releases a form of nitrogen into the soil that
plants can use.
• Then certain bacteria in the soil convert
nitrogen into a gas and it returns to the
atmosphere
Ecological Succession…..
• The gradual development of a community
over time.
Primary Succession…..
• When organisms grow in an areas where
they never have and they die there building
up “soil” in this area allowing organisms to
grow.
• The first organisms to row there are called
pioneer species.
Secondary Succession…..
• When an existing community is destroyed
by a natural disaster (fire or flood)
Mature Communities and
Biodiversity…..
• In early stages of succession, only a few species
grow.
• They usually grow quickly and make many seeds
• All species are vulnerable to disease, disturbances,
and competition
• As the community matures, it is dominated by
well adapted climax species
Biodiversity…..
• The variety of species found in a
community
• The more diversity in a community the
better the community will be…WHY ?