Food Chains and Food Webs

What is a food chain?• A food chain is “a sequence of organisms,

each of which uses the next, lower member of the sequence as a food source1”

Let’s Lookat a

Food Chain• A food chain is a

simplified way to look at the energy that passes from producers to consumers.

Important facts about food chains

• In a food chain each organism obtains energy from the one at the level below.

• Plants are called producers because they create their own food through photosynthesis3

• Animals are consumers because they cannot create their own food, they must eat plants or other animals to get the energy that they need.

Producers

• Producers make their own food

• Green plants use energy from the sun to make food

• Producers are on the bottom of the food chain

Primary Producers

• Primary producers are “organisms capable of producing their own food4”

• We can also say that they are photosynthetic, use light energy.

• Examples of primary producers include algae, phytoplankton, and large plants.

• Primary producers are eaten by primary consumers (herbivores)

Primary Producers of NJ Marshes

http://www.nicerweb.com/doc/class/pix/PRAIRIE/2005_07_18/Typha_angustifolia.jpg

Cattails

Marsh

Mallo

w

http://www.ncdot.org/doh/Operations/dp_chief_eng/roadside/wildflowerbook/graphics/images/page14a.jpg

http://www.ontariowildflower.com/images/blueflag2.jpg

Blu

e Flag

Iris

http://wisplants.uwsp.edu/scripts/detail.asp?SpCode=THEPALvPUB

Marsh

Fern

Consumers

• Consumers hunt, gather, and store food because they cannot make their own.

Four types of consumers

• Herbivores: animals that eat only plants3

• Carnivores: animals that eat only other animals3.

• Omnivores: animals that eat animals and plants3.

• Detritivores: Animals that eat dead materials and organic wastes

Other Ways to Classify Consumers

1. Primary Consumers: Herbivores3.

2. Secondary Consumers: Carnivores that eat herbivores3.

3. Tertiary Consumers: Carnivores that eat other carnivores3.

Herbivores

• Animals who eat plants such as:–grasshoppers–rabbits–squirrels–deer–pandas

Carnivores

• Animals who only eat other animals such as:–tigers–lions–hawks–wolves–cougars

Omnivores

• Animals who eat both plants and animals such as:–humans–bears

Primary Consumers in Marshes

Muskrat (eats mostly Cattails)

http://www.advancedwildlifecontrolllc.com/images/muskrat.jpg

http://wdfw.wa.gov/wlm/living/graphics/muskrat1.jpg

Primary Consumers in Marshes

• Wood Duck eats seeds like those of the Swamp Marsh Mallow and Blue Flag Iris

http://dsf.chesco.org/ccparks/lib/ccparks/wood_duck_pair.jpg

Primary Consumers in Marshes

• Glassy-winged Toothpick Grasshopper – eats leaves of plants like cattail and pickerelweed

http://bugguide.net/node/view/41662

Secondary Consumers

• Black Rat Snake eats eggs of animals like wood duck

http://www.bio.davidson.edu/projects/tate/Terms.htm

Secondary Consumers

• Swamp Sparrow eats seeds but also insects like the toothpick grasshopper

http://www.jeaniron.ca/2007/SwampSparrow6645.jpg

Tertiary Consumers• Eat other animals in marsh including snake

and sparrow

www.audubon.org www.montereybay.com

Osprey

Omnivore• Racoon eats seeds, fruits, insects, worms, fish,

and frogs… and pretty much anything else they can get their paws on!

http://abouttitusville.com/BobPaty/Animals/images/Racoon.jpg

Detritivore

• Worms are common detritivores in many ecosystems including marshes

Decomposers

• Microorganisms that are able to break down large molecules into smaller parts

• Decomposers return the nutrients that are in a living thing to the soil

What is a food web?A food web is “an interlocking pattern of food chains2”

What is a Food Web?• A more realistic way of looking at

the relationship of plants and animals in an environment

• Several food chains linked together• A predator from one food chain

may be linked to the prey of another food chain

Food Webs

• How many food chains can you make from this food web?