Community Ecology Chapter 37 Sections 8-9; Energy in Ecosystem & Trophic Levels Pgs ; Objective: I can describe how a community is based on how energy flows through the ecosystem, and I can identify different organisms according to trophic levels.

Energy in Ecosystems When organisms eat other organism, gain matter and energy When organisms eat other organism, gain matter and energy Source of all energy = Source of all energy = the sun Trophic Level = a step in energy transfer Trophic Level = a step in energy transfer a.k.a. level of nourishment in food chain This diagram shows what organisms eat what AND how energy flows What is this diagram called? FOOD CHAIN

Labels for Trophic Levels Producers a.k.a. Autotrophs: organisms that make their own food from non-living Producers a.k.a. Autotrophs: organisms that make their own food from non-living Example: Plants don’t eat other organisms Example: Plants don’t eat other organisms Consumers a.k.a. Heterotrophs: organisms that eat other organisms: can’t make own food Consumers a.k.a. Heterotrophs: organisms that eat other organisms: can’t make own food Example: Animals Example: Animals Can label primary, secondary, tertiary… Can label primary, secondary, tertiary… Decomposers Decomposers a.k.a. Detritivores a.k.a. Detritivores Eat and break down dead organic matter Eat and break down dead organic matter Primary Secondary Tertiary Example: Bacteria 1 st TL 2 nd TL 3 rd TL4 th TL 5 th TL Labels & #’s for Trophic Levels Always 1 st trophic level Always 2 nd trophic level or higher Always last trophic level Be careful! TL and primary What type of organism? What are some conclusions about associations between labels and #

Types of Consumers (other labels) Herbivore: Herbivore: Carnivore: Carnivore: Omnivore: Omnivore: A consumer that only eats plants (producers) A consumer that only eats animals (other consumers) A consumer that eats both producers and consumers Always 2 nd trophic level = primary consumer Always 3 rd trophic level = Secondary Consumer and/or higher… Could be any level of consumer (never 1 st trophic level)

How Organisms Eat Food Web: multiple food chains combined Food Web: multiple food chains combined Feeding relationships and energy flow of MANY organisms within an ecosystem Feeding relationships and energy flow of MANY organisms within an ecosystem Generalist: a consumer that eats a wide variety of different organisms Generalist: a consumer that eats a wide variety of different organisms Specialist: a consumer that eats only a few types of other organisms Specialist: a consumer that eats only a few types of other organisms

Food Chains and Food Webs Shows energy flow through trophic levels Shows energy flow through trophic levels Know how population changes… Know relationships + trophic levels

Loss of Energy Organisms eat = get energy Organisms eat = get energy But 100% not retained…why not? But 100% not retained…why not? Energy lost: metabolic processes + heat Energy lost: metabolic processes + heat Only get 5~20% of energy from food Only get 5~20% of energy from food  10% Rule Survivor Scenario Producers only capture about 1% of sun’s energy!

Energy Pyramid or Pyramid of Production Diagrams to show loss of energy Diagrams to show loss of energy Higher trophic levels need to eat more Higher trophic levels need to eat more Fewer organisms in higher trophic levels Fewer organisms in higher trophic levels Energy supply limits length of food chain Energy supply limits length of food chain Primary production = energy made by producers Primary production = energy made by producers

Matter vs. Energy Energy flows in one direction (change form over time, but eventually lost from earth) Energy flows in one direction (change form over time, but eventually lost from earth) Source of all energy on earth = Source of all energy on earth =sun Matter cycles within the earth Matter cycles within the earth will change forms (but will not lose from earth) will change forms (but will not lose from earth)