Download
ecosystem productivity n.
Skip this Video
Loading SlideShow in 5 Seconds..
Ecosystem Productivity PowerPoint Presentation
Download Presentation
Ecosystem Productivity

Ecosystem Productivity

343 Vues Download Presentation
Télécharger la présentation

Ecosystem Productivity

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Ecosystem Productivity Principles of Ecology

  2. Primary productivity • The rate at which producers capture & store energy in their tissues • Gross = total • Net = after respiration • The most productive ecosystems in the world  estuaries, swamps, marshes, tropical rain forest

  3. Factors influencing primary productivity • Climate & nutrients • Morphology & size of organism • Rainfall • Temperature • Season • Soil (mineral & nutrient availability)

  4. Net primary production per unit area of the world’s common ecosystems www.globalchange.umich.edu/

  5. Trophic Levels • Feeding levels with respect to primary source of energy • Producers & consumers each occupy a different trophic level • Energy is lost at each level

  6. Trophic Levels Heat Heat Decomposer 1stTrophic Level Producers Plants 2ndTrophic Level Primary Consumers Herbivores 3rdTrophic Level Secondary Consumers Carnivores

  7. Biomass Pyramids 3rdTrophic Level Carnivores Heat Heat 2ndTrophic Level Herbivores 1stTrophic Level Producers Plants Decomposer

  8. Biomass Pyramid • The total weight of all living organisms • Biomass at each trophic level  biomass pyramid 1.5 Biomass pyramid (grams/m2) Top carnivores 11 Primary carnivores 37 Herbivores 809 Detrivores/ decomposers Producers 5

  9. Biomass Pyramids 3rdTrophic Level Carnivores Heat Heat 2ndTrophic Level Herbivores 1stTrophic Level Producers Plants Decomposer

  10. Biomass Pyramids Heat Heat At each level some biomass is not passed to next higher level Decomposer

  11. Biomass decreases at higher trophic levels Not all biomass is consumed from one trophic level to next • Not all that is consumed • Not all that is consumed is digestible • Not all that is digested is turned into mass • Part of mass is converted to energy or heat • Lost mass is available for decomposition

  12. Vegetarianism Shorter food chain/web = less loss of energy • Supports idea that vegetarianism is the best way to feed a large population • Results in a decrease of human position on food chain Will this solve the worldfood problem?

  13. The “Cellulose Solution” • Cellulose  most abundant, naturally occuring organic molecule on earth • Humans can’t digest it • Ruminants can digest it • Cattle, sheep, goats • Deer, bison, antelope, moose, elk • “Hind-gut fermentors” can digest cellulose • Horses, rabbits, some rodents Drawing by Mike Hale Cellulose