Ecosystem Relationships How Energy Flows Through Ecosystems.

Ecosystem Ecosystem RelationshipsRelationships

How Energy Flows How Energy Flows Through EcosystemsThrough Ecosystems

ReflectionReflection

Take out a paper and use the next five minutes Take out a paper and use the next five minutes to write down 1-2 arguments FOR to write down 1-2 arguments FOR vegetarianism.vegetarianism.

Think-Pair-ShareThink-Pair-Share Group DiscussionGroup Discussion

Feeding Relationships in Feeding Relationships in EcosystemsEcosystems

What relationships are important in What relationships are important in ecosystems?ecosystems?

What is an ecosystem?What is an ecosystem? What is an environment?What is an environment? What are some ways we can classify What are some ways we can classify

the living things in an ecosystem?the living things in an ecosystem?

Food Chains – An OverviewFood Chains – An Overview

Food Chain OverviewFood Chain Overview

Some New Vocabulary…Some New Vocabulary…

Trophic levels: Trophic levels: – the feeding levels in a food chain or food web.the feeding levels in a food chain or food web.

Producers:Producers:– plants that turn radiant energy from the sun plants that turn radiant energy from the sun

into chemical energy for ecosystems.into chemical energy for ecosystems.– 11stst trophic level trophic level

Primary Consumers:Primary Consumers:– the first consuming organism in a food chain the first consuming organism in a food chain

(an herbivore or an omnivore).(an herbivore or an omnivore).– 22ndnd Trophic Level Trophic Level

Some New VocabularySome New Vocabulary Secondary Consumers:Secondary Consumers:

– a second consuming organism in a food chain (a a second consuming organism in a food chain (a carnivore or an omnivore).carnivore or an omnivore).

– 33rdrd trophic level trophic level Tertiary Consumers:Tertiary Consumers:

– a third consuming organism in a food chain (usually a a third consuming organism in a food chain (usually a top carnivore but can be an omnivore). Ex: ?top carnivore but can be an omnivore). Ex: ?

– 44thth trophic level trophic level Detrivores:Detrivores:

– an organism that consumes dead material and animal an organism that consumes dead material and animal wastes; includes decomposers.wastes; includes decomposers.

– decomposers break down cells and extract remaining decomposers break down cells and extract remaining energy.energy.

You and Food ChainsYou and Food Chains Make a list of what you’ve eaten in your Make a list of what you’ve eaten in your

last two meals.last two meals. For processed foods list all the ingredients For processed foods list all the ingredients

that come from living things.that come from living things. Divide your list into animal matter and Divide your list into animal matter and

plant matter.plant matter. Divide the animal matter into herbivores Divide the animal matter into herbivores

(such as cows) and carnivores (such as (such as cows) and carnivores (such as tuna). Record omnivores (such as tuna). Record omnivores (such as chickens) in both groups.chickens) in both groups.

From your data draw three food chains to From your data draw three food chains to which you are linked.which you are linked.

You and Food ChainsYou and Food Chains

What kinds of organisms are at the What kinds of organisms are at the start of every food chain?start of every food chain?

Do any of your food chains have Do any of your food chains have more than three links? Why?more than three links? Why?

For what species might you become For what species might you become food?food?

Volunteers to generate a chain?Volunteers to generate a chain?

From Land to Mouth (p. 6)From Land to Mouth (p. 6)

Group discussion:Group discussion: Divide the data into producers and Divide the data into producers and

consumers.consumers. Which group has the highest energy Which group has the highest energy

production on average?production on average? Do plants vary a little or a lot in their Do plants vary a little or a lot in their

energy production? Why?energy production? Why? Is it more efficient for people to eat Is it more efficient for people to eat

plant or animal products? Why?plant or animal products? Why?

Where Does the Energy Go?Where Does the Energy Go?

Food energy that is taken in by a Food energy that is taken in by a consumer is used by that organism. consumer is used by that organism.

Only about 10% is converted to new Only about 10% is converted to new tissues.tissues.

Energy is lost to waste and thermal Energy is lost to waste and thermal energy.energy.

Photosynthesis?Photosynthesis? Cellular Respiration?Cellular Respiration?

Pyramid of NumbersPyramid of NumbersRelative population sizes of each trophic level in an ecosystem.

Pyramid of NumbersPyramid of Numbers

ExceptionsExceptions

Pyramid of BiomassPyramid of BiomassShows the relative dry mass in grams per square metre (g/m2) of organisms in a food chain.

Pyramid of BiomassPyramid of Biomass

Pyramid of Energy FlowPyramid of Energy FlowShows the decrease in energy that is available to each successive trophic level.

Which Should We Use?Which Should We Use?

All are useful in different ways and All are useful in different ways and tell us different things about the tell us different things about the feeding relationships in a food chain.feeding relationships in a food chain.

Build your own pyramid (your choice) Build your own pyramid (your choice) for a pond ecosystem.for a pond ecosystem.

Questions to ConsiderQuestions to Consider

To study the transfer of food energy To study the transfer of food energy from dogs to fleas, which pyramid from dogs to fleas, which pyramid would you use? would you use?

Ecosystem A has a plant biomass of Ecosystem A has a plant biomass of ‘X’. Ecosystem B has a plant biomass ‘X’. Ecosystem B has a plant biomass of ‘2X’. Suggest which ecosystem of ‘2X’. Suggest which ecosystem has the largest populations of has the largest populations of consumers. Why?consumers. Why?

Food Chains vs. Food WebsFood Chains vs. Food Webs

• Disruptions

•Ripple Effects

•Food chains show linear feeding relationships.

Food Chains vs. Food WebsFood Chains vs. Food Webs•Non-linear feeding relationships.

•More than one feeding option.

•Disruptions?

•Ripple effect?

•Which is a better alternative? Food chain or food web?

•Which do you think is more common in nature?

Dibbles, Dinks, Woks & DorgsDibbles, Dinks, Woks & Dorgs

Please answer all questions and hand Please answer all questions and hand in at the end of class or at the in at the end of class or at the beginning of next class.beginning of next class.