Look at page 136, this is your homework due next class.

Look at page 136, this is your homework due next class.

Energy Flow and Cycles in Ecosystems What s the matter? Where is the energy? Will I ever see carbon?

What is an ecosystem and where does it fit on the biological scale? Do you remember? Sub-Atomic Particles Atoms Molecules Macromolecules Organelles Cells Tissue Organs Organ System Organism Population Community Ecosystem Biome Biosphere Solar System Universe Atom Molecule Macromolecule Organelle Cell Tissue Organ System Organism Population Community Ecosystem Biome Biosphere

I. Ecosystems and Energy Flow A. An ecosystem is a biological community of interacting organisms and their physical environment. B. Ecosystems require a constant input of energy from either the sun or organic compounds.

What is the ultimate source of energy on plant earth? II. Energy flows when organisms eat Sun s energy photosynthesis glucose A. Autotroph = make their own food from chemicals or light B. B. Heterotroph = must obtain food from environment How do organism obtain energy?

How are organisms arranged in ecosystems? a. Herbivore = eat plants b. Omnivore = eat flesh and plants c. Carnivore = eat flesh d. Scavenger = feed on organisms that recently died III. Trophic Levels (feeding levels) A. Producers = autotrophs that make their own food B. Consumers = heterotrophs that eat other plants and animals C. Decomposers = break down dead tissue and waste

Which of these are producers?

IV. Types of Producers A. Photoautotrophs- use light to make food B. Chemoautotrophs- use chemicals to make food C. Examples: Plants, algae some bacteria

V. How are consumers classified? A. First Level Consumer - feed on producers (Herbivores) The zebra eats the grass. B. Second Level Consumer - eat first level consumers (Carnivores) The lion eats the zebra. C. Tertiary Consumers - eat second level consumers (Carnivores) The vulture eats the lion. *Omnivores can be first, second, or third level consumers.

Which of these are first level consumers?

What is another name for first level consumers?

Herbivore

Which of these are second level consumers?

What is another name for a second level consumer?

Carnivore

Food Chain VI. Energy Pathways in Ecosystems A. Food Chain = represents a single pathway (a specific order) of energy and matter flow through an ecosystem. a. Arrows represent the flow or transfer of energy What do the arrows represent? b. Not accurate; organisms eat more than one species c. Always begin with a producer

B. Food Web = represent multiple pathways of energy and matter flow in ecosystems a. Include many intersecting food chains b. Most accurate

Aquatic Food Web

Make a Food Chain Pg 139 Eagle Daisy Frog Coyote Grasshopper

Answer: Notice the direction of the arrows. This shows the flow of energy

FOOD CHAIN page 139 Producers Primary Consumer Secondary Consumer Tertiary Consumer Grass Grasshopper Snake Hawk Water Nutrients Fungi /Bacteria Decomposers Draw into Notebook

Make a food web Page 138 Fungi Mountain Goat Bear Ladybug Deer Oak Tree Sparrow Barn owl Grass Spider Fox

STOP Food Web Activity

IN: Where did you get your energy today? The ultimate source of energy on planet earth is the sun! Energy flows when organisms eat.

I. Trophic Structure and the Flow of Matter and Energy A.Trophic (Feeding )Levels = organisms that are the same number of steps from the sun a. Primary producers (autotrophs) Incorporate sunlight into chemical bonds of glucose by photosynthesis b. Primary, secondary & tertiary consumers Break chemical bonds of glucose to get energy by cellular respiration

B. Matter and Energy a. Flow in and out of ecosystems b. Are recycled within ecosystems c. Matter + Energy (IN) = Matter + Energy (OUT) Flow Cycle Conserved Ecosystems

Flow Cycle Conserve

C. Laws of Matter and Energy Apply to Trophic Structure a. Matter and energy can not be created or destroyed. First Law b. C, H, O, and N are conserved (combine and recombine) to make new molecules as they move through ecosystems. c. There is a gradual loss of energy as it flows through ecosystems. Second Law d. Organisms use energy for growth, metabolism, and repair. Or, it is lost as heat to the environment.

II. Ecological Pyramids = graphical representations (pictures) of trophic structure (feeding levels)

A. Three Types of Ecological Pyramids a. Numbers Pyramid = represents the total number of individuals per unit area Large numbers of producers form the base.

b. Biomass Pyramid = represents the amount of biomass (dry weight) of living organisms in a given area at a given time What are the units used for a biomass pyramid?

c. Productivity (Energy) Pyramid = represents the flow of energy through each trophic level at a fixed time What are the units used for an energy pyramid?

What do you notice about the numbers in each of the pyramids below?

III. 10 % Rule a. Only about 10% of the energy entering a trophic level is transferred to the trophic level above. b. 90% LOST at each level c. Energy pyramids have a step-like pattern because less energy enters each trophic level up the food chain. https://www.youtube.com/watch?v=scizkxmleom&list=pl _4WORZB5ZcqIvhtZefDq7HHVxb1f92l8 DO DEMO 90% LOST 10% 100%

DEMO Materials: food coloring, 1000, 100, 10 ml graduated cylinders, one graduated 1ml transfer pipette Fill a 1000ml Flask with colored water. (Have student write 1000 ml on board) Pour 100 ml into 100 ml graduated cylinder. (Have student write 100 ml on board) Ask: What should I do with the rest of the water in the flask if it represents the energy available in the producers? (throw it away..lost) Repeat for 100 ml and 10 ml cylinders (Have student write 10 ml and write 1 ml on board) Show off tiny 1 ml transfer pipette. Ask: What does 1ml volume represent? (the only energy left to the 3 rd level consumers) Ask: Where did all the lost energy go if this is a model of energy flow in a real ecosystem? ( growth, metabolism, repair, lost as heat to the environment) Ask: Why do fewer organisms occupy the higher trophic levels? (Inefficiency in energy transfer between each trophic level)

OUT: Grass Mouse Cat Coyote 10,000 calories Suppose 10,000 calories of energy are available at the level of the grasses. What is the total number of calories LOST by the time energy reaches the coyote? a. 90 calories b. 990 calories c. 9900 calories d. 9990 calories D. 10,000 units in grass 1000 units in mouse (10,000 X.9 = 9000 lost; 1000 left) 100 units in cat (1000 X.9 = 900 lost; 100 left) Easiest Way 10 units left in coyote (100 X.9 = 90 lost; 10 left ) 10,000 10 = 9990

Knowledge Targets Students know atoms of carbon, oxygen, hydrogen, and nitrogen are conserved (i.e., combined and recombined) to make new molecules as they move through the ecosystem. Students know energy flow, mass, and populations in ecology can be represented by pyramids. Students know only a fraction of matter consumed at lower trophic levels is transferred to higher trophic levels to produce growth and release energy through cellular respiration. Students know most energy is not transferred to higher trophic levels because it is used for growth, maintenance, repair, or lost as heat to the environment. Students know a small fraction of the energy from one trophic level is transferred to the next higher trophic level. Students know there are fewer organisms at the higher trophic levels of a food web. Performance Targets Students can apply the concept of conservation of matter and energy to food webs and trophic levels. Students can identify the relative proportion of organisms at each trophic level (i.e., lowest trophic level has the greatest biomass and stored energy). Students can use mathematical representations to account for the energy transferred through each trophic level within a food chain. Students can explain there are fewer organisms occupying the higher trophic levels due to inefficiency in energy transfer between each trophic level.