logging in or signing up Energy flow Power Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 1697 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: May 12, 2008 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript Energy Flow through Ecological Systems : Energy Flow through Ecological Systems The other balance of life… Photosynthesis : Photosynthesis Again, the equation for photosynthesis is: 6 CO2 + 6H2O + light energy C6H12O6 + 6 O2 This equation leaves out important details: 1. Where does the O2 gas come from? 2. How is light energy converted into chemical bond energy? Photosynthesis : Photosynthesis Why is it so important to life? It is estimated that 99% of the energy used by living cells comes from the sun!!!!! Incorporation of sunlight into chemical bonds occurs through the process of photosynthesis "Invented" by cyanobacteria about 2 billion years ago Oxygen is a waste product of photosynthesis All oxygen in atmosphere is believed to originate from photosynthesis Photosynthesis : Photosynthesis Also…... Photosynthesis begins the carbon cycle by fixing CO2 (carbon dioxide in the atmosphere) The oxygen released as a by-product has a major impact on the biosphere. Today's atmosphere would not have 21% oxygen if not for photosynthesis. Energy Flow Charts : Energy Flow Charts Your plot receives 10,000 kcal/m2/day of energy Tell us where it all goes!!! On butcher paper create an Energy Flow Diagram from a simple imaginary food chain, which demonstrates how this energy enters and exits your plot. What scientific laws apply to energy? : What scientific laws apply to energy? First and Second Laws of thermodynamics First law: energy is neither created or destroyed!!! General accounting… Second law: every step of energy transformation and flow through a system = gradual loss of the ability to do work. What happens to all of that energy anyway? : What happens to all of that energy anyway? Equator most light--- poles about ½ the amount 1/3 reflects off clouds, snow fields bounces back to space 1/3 warms sea/land 1/4 absorbed in evaporation drives water cycle 1% - 2% of light striking a forest is used by all other living beings. Equivalent only 1/5 of the gasoline you put in your car gets you to your destination…..bummer hey…. Trophic Levels : Trophic Levels Effects of Lindeman’s Efficiency(10% Rule) : Effects of Lindeman’s Efficiency(10% Rule) Top predators are sensitive to changes in the energy flow of an ecosystem Cannot have more than 4 or 5 levels on a trophic pyramid. Why? The amount of energy and space needed to feed animals on a higher trophic level would be larger than the amount of energy expended to forage for it Effects of Lindeman’s Efficiency (10 % Rule) : Effects of Lindeman’s Efficiency (10 % Rule) Omnivores (i.e., bears, humans, raccoons, opossums, coyotes, etc.) can switch trophic levels depending on the food sources that are available Eating at lower trophic levels can support more members of a population in an ecosystem/environment Humans and Energy Flow : Humans and Energy Flow Humans are omnivores Humans use approximately 40% of the net primary production on land Net primary production: the amount of available energy that is produced in photosynthesis (after plants use what they need for survival) Energy Flow and Eating Habits : Energy Flow and Eating Habits Meat eating (higher on the trophic pyramid) uses more energy than eating veggies 90% of the grain that we grow is used to feed livestock 100 kg of grain can feed: 10 kg of cow and 1 kg of steak eating people 10 kg of grain eating people (10x more) A simple food web………. : A simple food web………. Implications : Implications We observe this dynamic balance of energy flow at all levels of scale from the ecological system to the individual organism. Also, this is the algebra with which we can understand the consequences of our actions. You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.