Communities:Group of populations interacting within the same habitat. Usually as feeding relationshipsflow of energy.

Communities Within a community, species are identified

based on their role within a community: niche

3 Major Niches1. Producers

2. Consumers

3. Decomposers

Producers:All autotrophs. These convert unusable energy(solar) into usable(chemical) energy via the process of photosynthesis.EX: all plants, algae, photosynthetic bacteria

Consumers• Consume energy by

“eating/absorbing” other producers and consumers.

• All Heterotrophs are consumers

• Niches: Herbivores, Omnivores, Carnivores, Scavengers, Parasites, to name a few

DecomposersAKA: Detrivores• Return organic matter

to environment.

• Major decomposers are the bacteria and fungi

• However, some insects

and organisms like earthworms can be considered decomposers

Relationships in CommunitiesFood Chains: single feeding relationship.

Grass (Producer)

Mouse (Primary Consumer)

Fox (Secondary Consumer)

Mountain Lion (Tertiary Consumer)

Food Chains All food chains must begin with producers. Arrows represent flow of energy. Trophic levels identify consumers. Generally primary consumers are

herbivores. Depending upon the food chain, some

organisms can occupy different trophic levels. Detrivores can occupy all trophic levels

Grass (Producer)

Mouse (Primary Consumer)

Fox (Secondary Consumer)

Mountain Lion (Tertiary Consumer)

Light energyPhotosynthesis

Chemical energycarbohydrates

Decompositionoccurs at anylevel of the chain

C,H,O,NSUNGLASSES

Food Webs Complex feeding relationships. Illustrates many food chains

Mt. Lion

Hawk

Deer

Snake

Goose

Fox

Grass Moss

Grasshopper

MOUSE

HAGH

Which organism seems to be the most important to this food web?

Keystone Species Plays a critical role in maintaining the overall

balance in an ecological community.

Stability of the communitydepends upon species. Keystone can occupy any level or niche.

Which organismseems to be the mostimportant to this food web?

Krill!

Food Web Activity