Transcript 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 ?