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Q/A Places and things that create a high Albedo effect are? ~ Pollution ~ Snow ~ Sand, rocks Energy Flow in Ecosystems Section 1.1 Energy flows in ecosystems Draper and Reed (2004). Our Environment: A Canadian Perspective, Third Edition Food Chains and Food Webs Energy is transferred from one organism to another along food chains Food chains show the sequence of who feeds on or decomposes whom in an ecosystem Every organism has a feeding or trophic level Trophic Levels 1st Trophic Level 2nd Trophic Level Primary Consumers; herbivores & omnivores 3rd Trophic Level Basic provider of food, plants (producers) Secondary Consumers; carnivores & omnivores 4th Trophic Level Tertiary Consumers; Carnivores that eat other carnivores & omnivores Food Webs show all of the complex feeding relationships between organisms in an ecosystem Humans have claimed nearly 40% of the terrestrial food supply, leaving only 60% for the millions of other organisms http://www.youtube.com/watch?v=TE6w qG4nb3M&feature=related Limits on Energy Transfer Not all of the energy that a plant creates can be transferred to the animal that eats it The plant uses most of that energy to stay alive and grow Once an animal eats a plant it doesn’t store all of that energy Most of the energy is used to move its limbs, pump blood, keep warm, etc. Q/ A While looking at an ecosystem, you observed this food chain: sun, algae, tadpole, fish, alligator. What are the trophic levels being observed? What is happening to the energy through this food chain? The higher up the food chain you go, the less energy is available In every ecosystem there is less energy available to secondary consumers than there is to primary consumers http://www.brainpop.com/science/ecolog yandbehavior/foodchains/ Thermodynamics The study of energy transformations The first law of thermodynamics – states that although energy can be changed from one form to another, it cannot be created or destroyed Thermodynamics The second law of thermodynamics – states that during any energy change, some of the energy is changed into an unusable form, usually thermal energy (heat) that cannot be passed on Each time energy is changed some energy is “lost” At each step in the chain less energy is available Q/A What are the two laws of Thermodynamics ? Explain in your own words. Energy Pyramids Show the energy flow from one trophic level to another Roles in Ecosystems Each organism has its own place within an ecosystem Its place in the food web, its habitat, breeding area and active times are called its ecological niche. Each species in an ecosystem has a different niche. Why? Niches Hawk vs. Owl Hawk active during day, can soar above open fields, but can’t fly through dense bush. Eyes excellent in detecting colour. Owls have shorter wings, can hunt in forests or dense areas, they also hunt at night. Eyes excellent in detecting motion. Zebra Mussel Zebra mussels came into Lake Erie in the late 1980’s from bilge water discharged by ships. Natural habitat is the Caspian Sea in western Asia. From Lake Erie, it migrated to Lake Huron, Rideau Canal, Ohio River, Mississippi, and Gulf of Mexico. Video Competition for Niches When a new species enters an ecosystem, this sparks a competition for niches. New species= exotic species. However, this happens naturally. Think seeds carried by the wind, or animals who take root in a new area.