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 source 1 ”

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 photosynthesis 3 • Animals are consumers because they cannot create their own food, they must eat plants or other animals to get the energy that they need.

The Producers

Producers are the beginning of a simple food chain. Producers are plants and vegetables.

The Producers

All energy comes from the Sun and plants are the ones who make food with that energy. They use the process of photosynthesis. Plants also make loads of other nutrients for other organisms to eat.

Primary Producers • Primary producers are “organisms capable of producing their own food 4 ” • 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 Common Marshes

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

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

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

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

The Consumers

Consumers are the next link in a food chain. There are three levels of consumers.

•

Primary consumers (1 st Order)

–

Worms, insects, squirrels, mice: all eat plants (HERBIVORES) ex: squirrel eats acorns

•

Secondary consumers (2 nd Order)

–

Eat the primary consumers (CARNIVORES) example: cat eats squirrel

•Tertiary consumers (3 rd order) –Eat the primary and secondary consumers

(CARNIVORES) wolf eats cat and squirrel ex:

Other Ways to Classify Consumers 1. Primary Consumers: Herbivores.

2. Secondary Consumers: Carnivores that eat herbivores.

3. Tertiary Consumers: Carnivores that eat other carnivores.

Four types of consumer • Herbivores: animals that eat only plants 3 • Carnivores: animals that eat only other animals 3 .

• Omnivores: animals that eat animals and plants 3 .

• Detritivores: Animals that eat dead materials and organic wastes

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

Osprey

www.montereybay.com

www.audubon.org

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

The Decomposers The last links in the chain are the decomposers. (They break things down) Like bacteria, mold, fungi, mushrooms

•If you die, they eat you. •If you poop, they eat that. •If you lose a leaf, they eat it.

Whenever something that was alive dies, the decomposers get it.

Decomposers break down nutrients in the dead "stuff" and return it to the soil.

The producers can then use the nutrients and elements once it's in the soil. The decomposers complete the system, returning essential molecules to the producers.

What is a food web?

A food web is “an interlocking pattern of food chains 2 ”