Unit: Ecology Chapter 11: Ecosystems and Biomes Chapter 12: Interactions Within Ecosystems 11.1:Ecosystems support life 11.2: Matter cycles through ecosystems 11.3: Energy flows through ecosystems 11.4: Biomes contain many ecosystems

Review True or False? If false, correct them: Organisms in soil are an example of abiotic factors Organisms in soil are an example of biotic factors The amount of light available in an ecosystem affects the types and amount of plant life that will grow there True Plants use energy to make sugars through photosynthesis

All ecosystems need certain materials An organism’s needs are met by: materials, or matter, required by all living things Ex: food and water All materials an organism takes in are returned to the ecosystem – during or after its life This continuous movement of matter through living and nonliving parts = cycle (a series of events that happens over and over again) Matter in an ecosystem may change form, but never leaves It is cycled through the ecosystem Three of the most important cycles in ecosystems involve: Water, carbon, and nitrogen

Water cycles through ecosystems condensation precipitation evaporation groundwater runoff Surface: lakes, rivers, oceans Underground: between soil particles and cracks in rocks Glaciers and ice sheets Bodies Water: Hydrogen and Oxygen (H2O) Changes state as it cycles through the ecosystem: solid (ice/snow), liquid, gas (water vapor) Precipitation: rain, snow, sleet, mist, hail Evaporation: liquid  gas Condensation: gas  liquid Respiration: animals release water vapor when they breathe Transpiration: plants release water vapor, usually through their leaves

Carbon cycles through ecosystems Carbon is found in all living things Carbon enters living parts of an ecosystem through carbon dioxide gas Plants: photosynthesis Carbon dioxide is used to produce sugars (carbon compounds found in food and all living matter) Organisms break down the carbon compound to release sugars in food: called respiration Carbon is released and cycled back into the atmosphere as carbon dioxide When living things die and decay, the rest of the carbon making up that organism is released Carbon is stored underground as the remains of plants and animals that have been buried for millions of years decay slowly This decay changes the dead organisms into fossil fuels (ie coal and oil) When humans burn these fossil fuels (combustion), dust particles and gases containing carbon are released to the environment

photosynthesis respiration fossil fuels

Nitrogen cycles through ecosystem 4/5 of the air we breathe is nitrogen – a clear, colorless gas We also need nitrogen to live, and we must get it from plants Plants cannot use pure nitrogen gas either Plants absorb certain compounds of nitrogen (“fixed” nitrogen) and can absorb it through their roots Nitrogen can get into soils via lightning (the strike breaks apart pure nitrogen) Rain Bacteria that fix nitrogen (also found in the oceans) When organisms die, decomposers in the ocean or soil break them down: nitrogen is then returned to the atmosphere by bacteria that can break down nitrogen compounds into nitrogen gas

http://www. classzone. com/books/ml_sci_ca6/page_build. cfm http://www.classzone.com/books/ml_sci_ca6/page_build.cfm?id=none&u=4#%23

Links Chapter 16: http://www.uiweb.uidaho.edu/hesg/model.html Biomes Ecosystems: http://www.sciencebitz.com/?page_id=42