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, hailfall 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 ?