Unit 3 EcosystemsUnit 3 EcosystemsChapter 6Chapter 6

Part 1Part 1The Web Of Life p. 92The Web Of Life p. 92

&&

Food Relationships p. 93Food Relationships p. 93

Questions #3-9 in the bookQuestions #3-9 in the book

Define Ecosystem

Ecosystem = the network of relationships (interactions) among plants, animals and the non-living parts in an environment.

Differentiate the terms producers, consumer, decomposers. P. 93

Producer = a plant which can synthesize carbohydrates using carbon dioxide and the sun’s energy.

Actually “produce” their own food and food for the rest of the ecosystem

Other examples:GrassesTrees shrubsWater liliesFlowersVegetablesFruits

Consumers = All those organisms that have to eat (consume) plants or animals to obtain their food.

Differentiate the terms producers, consumer, decomposers. P. 93

Types of consumers

Primary Consumers: Animals that eat producers. Also called 1st. order consumers. (Ex. Rabbit, squirrels, grouse, insects)

Secondary Consumers: Animals that eat primary consumers. Also called 2nd. order consumers. (fox, owl, mink )

Tertiary Consumers: Animals that eat secondary consumers. Also called 3rd. order consumers. (Wolf, coyote, hawk)

• Decomposers = Simple organisms that obtain their food from dead/decaying organisms and wastes.

Differentiate the terms producers, consumer, decomposers. P. 94

Examples:WormsBacteriaFungiProtozoa

Consumers, producers & decomposers….

SimilaritiesSimilarities

All three are terms All three are terms referring to the way referring to the way organisms obtain food & organisms obtain food & energyenergy

DifferencesDifferences

The way they obtain foodThe way they obtain food

Producers make it, Producers make it,

Consumers eat it, Consumers eat it,

Decomposer feed on Decomposer feed on wastes & dead material.wastes & dead material.

Differentiate the terms food chain & food web. P. 94

Food chain = linear sequence representing the nutrition of various species from the simplest plant to the top carnivore.

Food web = a series of interconnecting food chains in an ecosystem.

Food Chain vsvs Food Web

Differentiate the terms food web & food chain. P. 94

Similarity

Both food chains and food webs show the flow of nutrients and energy in an ecosystem.

Difference

Food web is more complex

Food web is composed of several food chains

Food web is a more realistic picture of an ecosystem.

Identify examples of producers & consumersSee “Handout”

Producers

Primary Consumers

Secondary Consumers

Tertiary Consumers

Decomposers

Give an example of a food chain from fig. 6.4. P. 95

Note: The arrows indicate the flow of energy & nutrients from one level to the next

Tree

→

insect

→

insect eating bird →

hawk

Producer Primary consumer

2nd order consumer

3rd order consumer

Sample Food Chain

Draw an example of a food web containing humans. P. 94

ManCow

Mosquito

Hawk

Phytoplankton

fish

Grass Decomposer

Using figure 6.5 summarize the main energy flows in an ecosystem p. 95

Sun = source of all ecosystem energyProducers make food via photosynthesisConsumers eat plants and other consumers to get energy Each time energy moves from one organism to another, energy leaves the system in the form of heat.Decomposers return nutrients to the soil but energy is not recycled. It is lost!

Summary – Energy & Food WebsThe ultimate source of energy (for most ecosystems) is the sun

The ultimate fate of energy in ecosystems is for it to be lost as heat.

Energy and nutrients are passed from organism to organism through the food chain as one organism eats another.

Decomposers remove the last energy from the remains of organisms.

Inorganic nutrients are cycled, energy is not.

Question #14, 15 & #16 p. 98 make perfect review questions for the test..

Energy flow…another look!!