Chapter 3

The Biosphere

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Chapter 3.1 Concept Map

Ecology

7

BiosphereSpecies

Populations Communities EcosystemBiome

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Ecological pyramid

Food web

Omnivore

Producer

Heterotroph

Herbivore

Scavenger

Autotroph

Carnivore

Decomposer

Consumer

Food chain

Trophic level

Chapter 3.2 Concept Map13

Detritivore

Biomass

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H2O cycle Nitrogen cycleCarbon cycle

Biogeochemical Cycles

Chapter 3.3 Concept Map11

Transpiration

Evaporation

Nutrient Limitation

Primary Productivity

Limiting Nutrient Algal Bloom

Nitrogen fixation

Denitrification

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3.1 What is Ecology

Ecology: The study of organisms, their environment, and how they interact with each other. Includes studying things living and non-

living, but is still a large part of Biology.

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3.1 What is Ecology Biosphere: The part of the Earth that

sustains life. All living things on Earth are found in

the biosphere. If you shrank the Earth to the size of an

apple, the biosphere would be the thickness of the peel.

Includes from high in the sky to deep in the oceans.

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3.1 What is Ecology

Interactions Species: A group of organisms so similar to each

other they can mate and produce offspring Populations: Group of organisms in the same

species that live in the same place and interbreed.

Community: Many groups of different populations (different species as well) that live together. A collection of interacting populations

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3.1 What is Ecology

The interactions between organisms and the abiotic factors around them forms an ecosystem.

Different ecosystems: Terrestrial Aquatic

Marine Freshwater

Biomes: a group of ecosystems that have a climate and dominant communities

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3.2 Energy Flow There are many different

ways an organism can obtain the energy that it needs to survive.

First, some organisms can use the sun’s energy OR chemicals in the environment to produce energy for themselves

These organisms are called autotrophs. Photosynthesis Chemosynthesis

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3.2 Energy Flow

Second, there are organisms that must obtain energy from ingesting (eating) other organisms.

They are called heterotrophs.

Heterotrophs can eat plants, animals, or fungi in order to get energy.

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3.2 Heterotrophs Come in many forms.

CarnivoreEx. Lions, DogsScavenger- What would the Earth

look like if there were no scavengers?

HerbivoreEx. Cows, Wildebeests

OmnivoreEx. Humans, Raccoons, Opossums

DecomposersEx. Bacteria, Fungi

DetritivoresEx. Worms, snails, crabs

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3.2 Energy Flow

A food chain is a model scientists use to illustrate the flow of energy through an ecosystem. Ex. Grass » Cow » Human or

Algae » Carp » Heron » Lion Food chains usually have

no more than five steps. With each step the

amount of energy transferred decreases

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3.2 Energy Flow

In a food chain, each organism represents a different trophic level.

The word trophic is from the Greek tropho and basically means food.

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3.2 Energy Flow

The first trophic level usually consists of producers. Producers are autotrophs that produce their

own energy from sunlight or chemicals. The second level are the herbivores

which eat the producers. The third level are carnivores which eat

the herbivores. The fourth are the carnivore eaters, and

so on...

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3.2 An Ecological Pyramid

1st level- the producers/autotrophs

2nd level - the herbivores

3rd level - carnivores

Top level - carnivores

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3.2 Energy Flow

An ecological pyramid can describe the flow of energy (as seen on the last slide) or it can describe the amount of biomass that exists at that trophic level. Biomass is the actual weight of all of

the organisms at that trophic level.

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3.2 Energy Flow As you can see on the ecological pyramid,

the amount of energy retained decreases as you go up to the top.

With every passing level, 90% of all energy is lost! Only 10% of the producer’s energy actually

makes it into the herbivore’s system! Only 10% of the herbivore’s energy actually

makes it to the first carnivore in the chain! And so on…

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3.2 Energy Flow

The energy is lost in many different ways. The food must be digested Body tissues must be built (muscle,

skin, etc.) Some is given off as waste A lot as heat

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3.2 Energy Flow

In order to survive, a hawk eats 30 pounds of lizards in a month. In that same month in order to survive, those lizards have to eat 300 pounds of crickets. How many pounds of grass do those crickets have to eat in order to survive?

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3.2 Energy Flow

There is 9000 pounds of grass in one particular habitat. How many crickets can this habitat

sustain? How many lizards? Hawks?

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3.2 Energy Flow

A food chain is not that complicated, but in real life, feeding involves more than just a simple food chain.

A food web is more involved, and describes all of the possible feeding situations that can occur in an ecosystem.

See p. 71

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3.2 Food Web

Some “webbing”

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3.2 Food Web

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3.3 Cycles of Matter

Biogeochemical Cycles: When matter is passed from one organism to another or from one part of the biosphere to another.

Water Cycle

Carbon Cycle

Nitrogen Cycle

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3.3 Cycles of Matter Nutrient Limitation: Limitations being

put on the existence of organisms due to availability of nutrients in the ecosystem. Limiting Nutrient: The actual nutrient in the

ecosystem that is scarce or cycles very slowly. Algal Bloom: When an aquatic ecosystem gets a

rapid influx of its limiting nutrient causing a growth explosion of producers.

Primary Productivity: The rate at which organic matter is created by producers.

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Important Study Tips! Ecology/Ecosystem/Biosphere Heterotrophs/Autotrophs Consumers/Producers 1st, 2nd, 3rd Order heterotrophs Carnivores/

Scavengers/Detritivores/Omnivores/Herbivores/Decomposers

Food Chain/Food Web Water/Carbon/Nitrogen ENERGY PYRAMIDS! Nutrient Limitation