1 / 14

Chapter 57 – Dynamics of Ecosystems Trophic levels Nutrient flow

Chapter 57 – Dynamics of Ecosystems Trophic levels Nutrient flow Energy Flow Biodiversity Productivity. Question. Ecologists categorize species based upon their nutrients and energy sources What are sources of energy? heterotrophs autotrophs

donagh
Télécharger la présentation

Chapter 57 – Dynamics of Ecosystems Trophic levels Nutrient flow

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 57 – Dynamics of Ecosystems Trophic levels Nutrient flow Energy Flow Biodiversity Productivity Question Chapter 57 -- Dynamics of Ecosystems

  2. Ecologists categorize species based upon their nutrients and energy sources What are sources of energy? heterotrophs autotrophs What are sources of nutrients? producers consumers decomposers What is the final fate of energy? What happens to nutrients? Chapter 57 -- Dynamics of Ecosystems

  3. Knowledge of food chains helps us to understand ecosystem dynamics In 1997, ~500,000 short-tailed shearwater birds were found dead in the Bering Sea off Alaska. What happened? Climate shift favored Ehux Question Chapter 57 -- Dynamics of Ecosystems

  4. How do energy and nutrients move through an ecosystem? Food chains Trophic levels (feeding levels) Chapter 57 -- Dynamics of Ecosystems

  5. What happens to the energy as it passes through an ecosystem? Question Chapter 57 -- Dynamics of Ecosystems

  6. Why are food chains relatively short? Chapter 57 -- Dynamics of Ecosystems

  7. What do ‘ecological pyramids’ show? energy numbers biomass Inverted pyramids? FoodChain 1 Food Chain Foodchain 2 Chapter 57 -- Dynamics of Ecosystems

  8. Food webs How much disruption can a food web withstand? What is a “Keystone species”? e.g., CA sea otter Importance to Kelp Forests Conflicts with shellfish industry -- crabs, abalone Surge of sea urchins Chapter 57 -- Dynamics of Ecosystems

  9. How do nutrients flow through ecosystems? -- Biogeochemical Cycles Carbon cycle Carbon cycle Chapter 57 -- Dynamics of Ecosystems

  10. Do all essential nutirents flow through biogeochemcal cycles? Limiting nutrients Key steps of The N cycle Roles of Microorganisms Plants Animals Environmental issues Note: you are not responsible for the individual steps of the phosphorus cycle, but should have a general understanding of the role of P-related issues. Chapter 57 -- Dynamics of Ecosystems

  11. So why did DDT cause ecological harm? DDT and Bioaccumulation Which types of pollutants will tend to bioaccumulate? See page 1227 Question Chapter 57 -- Dynamics of Ecosystems

  12. How do disruptions to specific trophic levels affect ecosystems? Top down effects Restoring aspen growth in Yellowstone with wolves Bottom-up effects Disruption of producers Human impacts Adadpted from Ripple WJ and Bescht RL (2007) Restoring Yellowstone’s aspen with wolves. Biological Conseravation 138: 514-519 http://www.cof.orst.edu/leopold/papers/Restoring%20Yellowstone%20aspen%20with%20wolves.pdf Chapter 57 -- Dynamics of Ecosystems

  13. How many organisms exist within an ecosystem? “Biodiversity” Global diversity: 100 million??? What factors influence diversity? -- productivity -- climate -- habitat heterogeneity -- other species Diversity ‘hot spots’ Question Chapter 57 -- Dynamics of Ecosystems

  14. Ecosystems are diverse in their scale and dynamics Biomes to microscopic Simple to complex Of great longevity to the ephemeral Familiar to bizarre Redwood canopy Vernal pool Chapter 57 -- Dynamics of Ecosystems

More Related