Transcript Energy Flow
Energy Flow How does energy move through the ecosystem? http://www.armofthesea.info/images/landscapes/crommet_lg.jpg Conservation: • Law of Conservation of Matter – In any ordinary physical or chemical change, matter is neither created nor destroyed, only transformed from one form to another. • Law of Conservation of Energy – In any ordinary physical or chemical change, energy is neither created nor destroyed, only transformed from one form to another. Energy: • 2nd Law of Thermodynamics: –When energy is changed from one form to another, some energy will be lost to the larger environment. • Nothing is ever 100% efficient. • This is due to entropy (nature’s tendency towards randomness). How does energy flow through ecosystems? • Food Chain: A simple diagram of one string of feeding relationships in an ecosystem, showing the direction of the transfer of energy in that system. Sun Grass Rabbit Soil Wolf Bacteria What are the parts of a food chain? Producers • Organisms that make their own food from inorganic molecules and energy. – eg. Plants, blue-green algae Energy through is –Inorganic Most accomplish energy building almost always Molecules = photosynthesis from the sun molecules that are • H20 + Sunlight + CO2 Sugar + Orare 2 (very not part of a living exceptions) organism Consumers • Organisms that cannot make own food. – eg. all animals, fungi and most bacteria – Obtain energy by eating other organisms — through a process called cellular respiration • Sugar + O2 CO2 + H20 + energy Decomposers • Bacteria and fungi that break down organic material Decomposers are essential to ecosystem health because they recycle nutrients back for producers to reuse. Food Web: • a group of food chains showing all of the feeding relationships in an ecosystem. Food Web Sun Human Wolf Sheep Rabbit Grass MiceDeer Flower Fox Bacteria Carrots Nutrient Rich Soil Biological Magnification • Increasing concentration of a substance in organisms in higher trophic levels in a food chain or web. Many toxins in the water Many toxins in the person • Biological Magnificationaccumulation of increasing amounts of toxin within tissues of organisms. Video on Biological Magnification Food Webs con’t: • Trophic level — a layer in the feeding relationship of an ecosystem, one link in the food chain/web. • Biomass — total amount of organic material present in a trophic level. So, all producers are at the same trophic level and all primary consumers are at the next trophic level. Organic = is currently living or lived in the past Energy Pyramids http://www.vtaide.com/png/foodchains.htm http://www.earthforce.org/files/1284_image2_Energy_Pyramid_for_ Galvbay.jpg • Another way to look at trophic levels. • a diagram showing the relative amounts of energy/biomass in the different trophic levels. • Lowest trophic levels are at the bottom: Producers have the greatest biomass. Example of an Energy Pyramid 1 MAN MAN 0.1% 10% 100 % of the sun’s energy FOX 1% 10% 10% RABBIT Rabbit 90% Energy Lost during conversion to heat, waste…. 90% 10% Grass 90% 10 FOXES 100 RABBITS 1000 Bunches of GRASS - The decreasing size of the pyramid shows that each level of the pyramid has a smaller and smaller number of those organisms.