Each organism in a food web or chain represents a feeding step,or a "trophic level". Freshwater Pond Ecosystem water green-backed boatman heron mosquito 年 larva water catfish fleas algae rotifers 6
26 Each organism in a food web or chain represents a feeding step, or a “trophic level
3.Energy Flow (Energy Transfer) 27
27 3. Energy Flow （Energy Transfer)
Energy Flow Energy enters ecosystems from an external source.What is it? Energy flows linearly and exits an ecosystem through Food chains. What happens to the amount of energy as it travels through an ecosystem? 28
28 Energy Flow Energy enters ecosystems from an external source. What is it? Energy flows linearly and exits an ecosystem through Food chains. What happens to the amount of energy as it travels through an ecosystem?
Types of energy 1.heat energy 2.mechanical energy (+gravitational energy,etc.) 3.chemical energy energy stored in molecular bonds 4.Solar energy太阳能 Energy Unit::calory卡路里 joule焦耳 29
29 Types of energy 1. heat energy 2. mechanical energy (+gravitational energy, etc.) 3. chemical energy = energy stored in molecular bonds 4. Solar energy 太阳能 Energy Unit: calory 卡路里 joule 焦耳
Energy flow Sunlight Ecosystem Primary Producers (plants and other photosynthetic Production organisms) Heat Chemica energy Secondary Consumers (including animals) Production Heat Copyright Pearson Education.Inc.publishing as Benjamin Cummings
30 Primary Production Secondary Production Energy flow