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Ecosystems and Biomes. Topic G.2. Energy flow. Highest energy is in the producers who get their energy from the sun (NOT!!!!). Make that sunlight!
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Ecosystems and Biomes Topic G.2
Energy flow Highest energy is in the producers who get their energy from the sun (NOT!!!!). Make that sunlight! What happens to the energy as it is passed from one trophic level to the next? 80-95% is lost as heat or used by the organism in that trophic level for maintenance. Energy in excreted waste is transferred to decomposers as is energy in bodies of dead organisms
Pyramid of energy Units should be kJm-2yr-1
Gross production – the total amount of energy trapped in the organic matter produced by plants per area per time (kJ) Net production – gross production minus energy lost in respiration (the cellular type!) Gross – respiration = net production Biomass – the dry weight of anorganism measured in gm-2yr-1
Use the information at the bottom of page 565 to create a pyramid of energy. After completing the pyramid, check the top of page 566 to be sure you included all relevant items.
Pyramid of biomass See page 566 This similar to the pyramid of energy (pg. 563) and a pyramid of numbers (how many of each organism are present)
Ecological Succession The change in abiotic and biotic factors in an ecosystem over time. Seen when one species replaces another in an area Two types: Primary secondary
Primary succession Occurs on previously barren areas such as a new volcanic island Typically there is no soil present Lichens are pioneer plants which breakdown rock. Also, as they die they contribute to a thin layer of soil. Moss usually follows lichens As time goes on seeds are brought to the area in bird droppings or by the sea
Secondary succession An area is recolonized following a natural or artificial disaster. Some soil is present Seeds and roots may be present as well
Question? Describe succession on a glacial moraine.
Comparing primary and secondary succession See chart on page 568
Effect of Disturbances on Communities Includes storms, fires, floods, volcanoes What type of disturbances are common in Terrestrial environments Lakes streams, ponds Marine environments Volcanic islands
Not all disturbance is negative. Ex.) Yellowstone fires
Living organisms change the abiotic environment Increase amount of organic matter due to plant and animal death and decay Soil depth increases as organic matter builds up Plant roots reduce erosion Addition of humus (organic matter), improves soil quality and allows it to hold moisture as well as aerate Mineral recycling takes place