Feeding Relationships

Food ChainsFood Webs

Trophic Levels10% RuleBiomass

Food ChainFood chainA series of steps in an ecosystem in which organisms transfer energy by eating and by being eaten.

The sun is the original energy source for producers, but consumers rely on carbohydrates, proteins, and lipids for energy from the food they eat.

The arrows in a food chain show the flow of energy from the sun or hydrothermal vent to a top predator

Check Point:

Explain the significance of the arrow direction in a food chain

Food WebsFood WebNetwork of complex of feeding relationships.

A food web links all the food chains in an ecosystem together.

Draw Food Chain and Food Web

Trophic LevelsA step in a food chain or web is called a trophic level

Trophic Levels

Each consumer depends on the trophic level below for energy

Autotroph

Organism that is able to capture energy from sunlight or chemicals and make their own food.

Ex. Plant and Algae

Heterotroph

Organism that obtains food by consuming other living things, also called a consumer.

Ex. Lion and human

Autotrophs &Heterotrophs

SunAutotrophHeterotroph

Primary producers are autotrophs

Consumers are heterotrophs

Primary Producer Primary ConsumerSecondary Consumer

Tertiary ConsumerQuaternary Consumer

Food Web Analysis

Are there any primary consumers that can also be a secondary consumer?What would happen to the food web if –

A) The harvest mice where to die off in the area?

B) The algae died?

C) The grasshopper died?

Food Web

Food web Explains all of the feeding relationships at each trophic level in a community.

A food web is more realistic than a food chain since most organisms feed on more that one organism.

Food Web Example

Grass & Seeds

Grasshopper

American Kestrel Loggerhead Shrike

Cricket

Shrew

SparrowDeer Mouse

Cooper’s Hawk

Food Web Activity

10% Rule

As energy is transferred from one trophic level to the next 90% of the energy is lost as heat to the environment

Why do we call it the 10 % rule?Only 10% of the available energy is transferred to the next trophic level

• New 10 % rule diagram so students can model their own

10% Rule

• Have the students create a diagram

Ecological Pyramids

• Ecological pyramids – show the relationships in food chains and food webs

• The bottom of the food pyramid represents the producers, the next level the herbivores, the next the 1st carnivore, and the next and/or top carnivore.

Producer

Herbivore

Carnivore

Ecological Pyramids

•Ecologists recognize three different types of ecological pyramids:•energy pyramids

•biomass pyramids

•pyramids of numbers

Energy Pyramid

• Energy Pyramid- Shows the relative amount of energy at each trophic level.

Energy Pyramid

Biomass Pyramid

•Biomass- The total amount of living organic matter at each trophic level.

Biomass Pyramid

Pyramid of Numbers

• Pyramid of numbers- Shows the relative number of individual organisms at each trophic level.

Pyramid of Numbers

What is Ecology?

Ecology- The study of organisms and how they interact with their environment. (includes both biotic and abiotic factors).

What is an Ecosystem?

Ecosystem- A collection of the organisms that live in a particular place together with their nonliving or physical environment.

Biotic & Abiotic Factors

Biotic factors – the biological influences on an organism within an ecosystem, the living cast of living characters.

Biotic v. Abiotic Factors

Abiotic factors – physical or non living factors that influence an ecosystem.

Levels of Organization within an Ecosystem

The study of ecology ranges from the study of individual organisms to the study of the entire biosphere.

1. Species (Individual)2. Population3. Community4. Ecosystem5. Biome 6. Biosphere

Levels of Organization

1. A species is a group of organisms that can breed and produce fertile offspring. (ex: black bears)

2. A population is a group of individuals that belong to the same species and live in the same area (ex: all the black bears in Yellowstone Park)

Levels of Organization

3. A community is a group of different populations that live together in a defined area. Exp. lions and tigers and bears living in the same area

4. A ecosystem is a collection of all the organisms that live in a particular place, together with their physical environment

Levels of Organization

5. A biome is a group of ecosystems that have the same climate and dominant communities.

6. A biosphere is the parts of the earth in which life exists, including land, water, air and atmosphere.

Ecology: Levels of Organization

The Niche

An organisms' niche is the full range of physical and biological conditions in which the organism lives and the way in which it uses those conditions.

The Niche

A organisms niche includes - the type of food it consumes - how it obtains food - physical conditions necessary to survive- the organism's reproductive pattern

Niche v. Habitat

An organisms habitat is where it lives. An organisms niche is how it lives.

No two species can share the No two species can share the same niche in the same same niche in the same habitat.habitat.

Bay-Breasted WarblerFeeds in the middlepart of the tree

Spruce treeYellow-Rumped WarblerFeeds in the lower part of the tree andat the bases of the middle branches

Cape May WarblerFeeds at the tips of branchesnear the top of the tree