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Transcript of ch2 ecosystems and biomeshome.mca.k12.pa.us/~candelorad/environmental... · Energy Pyramid (energy...
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Ecosystems and Biomes
Chapter 2
Section 1: Energy in Ecosystems
Energy Roles in the Ecosystem
� Producers
� Consumers
� Decomposers
Producers
� Plants
� Capture energy from the sun
� Main source of all the energy in an ecosystem
Consumers (3types)
� Herbivores- eat plants only (first level consumers)
� Omnivores- eat both plants and animals
� Carnivores- eat animals only
� Scavengers – a carnivore that feeds on dead animals
Decomposers
� Bacteria and fungi that decay (break down) dead organisms and return material to the soil
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Food Chain
� A sequence of events in which food energy is passed from one individual to another
Food Webs
� Ecosystems have many food chains
� An animal in one food chain often eats animals in other food chains
� When food chains overlap, it is called a food web
Energy Pyramid (energy flow)
� 1% of the sun’s energy is used by plants to make food
� Most of this energy is used up by the plant (only small amount stored)
� This energy is passed on to primary consumer who uses most of this energy (only 10% passed on)
� At each level of the pyramid, the amount of energy available decreases
Section 2: Cycles of Matter
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Water Cycle
� Evaporation, condensation, precipitation
� Transpiration- water vapor from plants
� Percolation- water seeping into ground
� Runoff
Carbon-Oxygen Cycle
� organisms need oxygen to release energy from their food (respiration)
� carbon dioxide is needed by plants to make food (photosynthesis)
� animals take in O2 and give off CO2
� plants take in CO2 and give off O2
� CO2 is given off when dead plants and animals decompose
Nitrogen Cycle
� Nitrogen-fixing bacteria in plant roots change N2 from the air into a form of nitrogen (NO3
-) plants can use
� The nitrogen becomes part of the plant.
� The nitrogen becomes part of the animal when the animal eats the plant
� Decomposers break down dead plants and animals and nitrogen is returned to the soil.