Energy Flow Through the Ecosystem

Energy and matter

The Earth has internal (chemical) and external (solar) energy.

That energy is used to move matter through the Earth’s systems.

Energy changes the physical and chemical properties of matter.

Sustaining Life on Earth Requires Energy and Matter

One-way flow

of EnergySun

Chemicals

Cycling

of Matter

Energy in Living Systems

Living systems use energy

Energy used for growth, reproduction and metabolism

No organism can create energy

Can store it, but not create it

http://ecology.com/wp-content/uploads/2011/09/sun.jpg

Ecosystem energy flow

Energy enters an ecosystem in 2 ways:Energy is “fixed” (stored in tissues) by organisms and moves through food webs.

Heat energy is transferred (air, water, soil convection) and warms life on Earth.

Sunlight is primary source of energy for most life on Earth

Exception: Chemicals used in deep sea vents

Primary Producers

Primary producers capture sunlight or chemicals and convert it into useable energy.

These organisms are called “autotrophs.”

http://people.westminstercollege.edu/faculty/tharrison/emigration/2_diatoms.gif

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Leaf_1_web.jpg/300px-Leaf_1_web.jpg

Primary Producers

Primary producers use solar or chemical energy to make complex organic compounds out of inorganic materials.Primary producers store energy.

Used for their own energy needsAlso used by organisms that consume them

http://people.westminstercollege.edu/faculty/tharrison/emigration/2_diatoms.gif

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Leaf_1_web.jpg/300px-Leaf_1_web.jpg

Primary ProducersPrimary producers include plants, algae and certain bacteria.Use either

Photosynthesis: use solar energy to make carbohydrates; release oxygen

Phytoplankton (aquatic autotrophs) account for 50% of the oxygen produced

Chemosynthesis: use chemical energy to make carbohydrates

http://people.westminstercollege.edu/faculty/tharrison/emigration/2_diatoms.gif

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Leaf_1_web.jpg/300px-Leaf_1_web.jpg

Consumers = heterotrophs

Consumers (heterotrophs) rely on other organisms for energy and nutrients. Different types of consumers are classified by the way they get energy.

http://video.ecb.org/badger/download/vlc/images/VLC124_Consumers.jpg

Types of Consumers: Carnivores

Carnivores kill and eat other animals.

The process of obtaining meat requires energy but meat is generally high in energy and nutrients and is easy to digest.

http://producersconsumers.wikispaces.com/file/view/lionDD.jpg/37331363/lionDD.jpg

Types of Consumers:Herbivores

Herbivores obtain energy from plants: roots, leaves, stems, seeds or fruits.

Examples include koalas, cows, rabbits and deer.

http://www.eoearth.org/files/199301_199400/199323/koaladiet2.jpg

Types of Consumers:Omnivores

Omnivores eat a variety of foods including both plants and animals.

Example: Bears eat other animals but also eat berries and other plant products.

http://www.saburchill.com/images02/010805012.jpg

What about the human diet?Humans who are vegans (plant products only) can be considered _______________.

What about vegetarians who eat milk products? ___________________

Humans who eat meat and fat only can be considered____________.Humans who eat meat, vegetables and fruit can be considered ________________.

http://3.bp.blogspot.com/_gfZRLG7ChzA/TQVxb_hRoMI/AAAAAAAAAHk/62yyPSZjuIk/s1600/omnivore.jpg

Types of Consumers:Scavengers

Scavengers eat animals that have been killed by other animals or have died of other causes.

Vultures are scavengers.

http://1.bp.blogspot.com/-lbViVUxHu10/TiWOpgNdKNI/AAAAAAAAABk/QT7Hyi8tTFU/s400/vulture.jpg

Types of Consumers:Detritivores

Detritivores help decompose organic matter by consuming detritus: dead animal and plant parts and organic wastes.Commonly digest decomposers that live on or in detritus

http://www.theanimalfiles.com/images/detritivore.jpg

Earthworms are detritivores.

Types of Consumers:Decomposers

Decomposers chemically break down organic matter and use it for energy.

Release inorganic compounds into soil

Decomposers include bacteria and fungi.

Mushrooms are types of fungi.

http://www.scienceiscool.info/pseudomonas_bacteria.jpg

http://www.geography4kids.com/files/art/land_chain4_240.jpg

Decomposers and detritivores

Energy Flow in an Ecosystem: Food Chains and Food Webs

http://www.sleepingdogstudios.com/Network/Biology/foodweb_2.gif

Energy flows through an ecosystem in one direction -- from producers to various levels of consumers.

Producers and consumers are linked through feeding relationships.

Energy Flows Through “Trophic Levels”

Each step of a food web or food chain is called a trophic level.

Energy flows up from one trophic level to the next.

http://belizesharks.org/wp-content/uploads/2012/02/trophiclevels.jpg

Trophic Levels

First Trophic LevelFirst Trophic Level

Second Trophic LevelSecond Trophic Level

Third Trophic LevelThird Trophic Level

Fourth Trophic LevelFourth Trophic Level

Producers (plants)Producers (plants)

Primary consumers Primary consumers (herbivores)(herbivores)

Feed directly on Feed directly on producersproducers

Secondary consumer Secondary consumer (carnivores)(carnivores)

Feed on Primary Feed on Primary ConsumersConsumers

Tertiary consumerTertiary consumerFeed on other carnivoresFeed on other carnivores

Food Chains

Food chains are the series of steps through which organisms transfer energy by eating or being eaten.

Can be short or longhttp://gis.bcsd5.org/Inspiration/Food%20Chain.jpg

Food Webs

Food Web = more complicated network of feeding interactions

Include interconnected food chains

Removal of one organism affects all other members of the web.

Remember: Decomposers and detritivores play an important role by releasing organic nutrients that canbe used by the primary producers.

Identify three food chains within this food web.

http://silverfalls.k12.or.us/staff/Read_Shari/mysite/foodweb1.jpg

Which is shortest?____________________________Which is longest? ____________________________Describe the possible effectsof a grasshopperextinction.__________________________________________Note: Energy flows in the direction

of the arrow.

Ecological Pyramids

Diagrams used to show the relative amounts of energy or matter in each trophic level of a food chain or food web.

Three types:Pyramids of Energy

Pyramids of Biomass

Pyramids of Numbers

Pyramid of Energy

Shows the relative amount of energy available at each trophic level of a food chain or food web

Pyramid of Energy: 10% Rule

As energy is transferred up to the next trophic level, 90% of the energy is lost.Only 10% of the energy within one trophic level is transferred to the next level.

Pyramid of Energy: 10% Rule

Example: A bird (1st consumer) eats plant seeds (primary producer). Only 10% of the energy in the grass will be stored in the tissues of the bird.How much of the energy from the grass will be stored in the tissues of the hawk that eats the bird? ___________________

Pyramid of Biomass

The total dry mass of organisms in a trophic level is its “biomass”.

A pyramid of biomass shows the relative amount of organic matter at each level.

Most at primary producer level; least at the top trophic level

http://images.tutorvista.com/content/ecosystem/biomass-upright-pyramid.jpeg

What does this say about the amount of primary producer biomass required to support tertiary consumers?

Pyramid of Numbers

Shows the relative number of individual organisms at each trophic level

Generally follows the same pattern as the pyramid of biomass

http://images.tutorvista.com/content/ecosystem/upright-pyramid-of-numbers-grassland-pond.jpeg