ENERGY FLOW and COMMUNITY INTERACTIONS Chapter 2; pages

ENERGY FLOW What is an ecosystem? It is a self supporting unit of interacting organisms and their environment.

ENERGY FLOW Ecosystems have 4 characteristics: Capture energy and store it in glucose (photosynthesis) Transfer energy (respiration) Decompose Recycle/Reuse

THE ULTIMATE SOURCE OF ENERGY THE SUN

CAPTURE AND STORE ENERGY The sun’s energy can be captured and stored in glucose through photosynthesis. ENERGY

TRANSFER ENERGY Pages Organisms in ecosystems transfer energy from organism to organism Energy is transferred in a linear chain What part of the food chain shows the transfer of energy? sunlight FOOD CHAIN

TRANSFER ENERGY Can you identify?: –Producers (autotrophs) –Consumers (heterotrophs) –Herbivores (heterotrophs) –Carnivores (heterotrophs) –Omnivores (heterotrophs) sunlight FOOD CHAIN

TRANSFER ENERGY Interacting food chains are known as a food web.

TRANSFER ENERGY Food chains can be shown as trophic levels (level at which an organism feeds) PRODUCERS PRIMARY CONSUMERS 2 ND CONSUMERS 3 RD CONSUMERS 4 TH CONSUMERS

DECOMPOSE Where do all the dead things go? They are eaten. Yummmmm! They decay. Smelly! decomposer detritivore

DECOMPOSE Detritivore Feeds on the remains of dead plants and animals and other organic matter Decomposers Breaks down dead organic matter. Bacteria and fungi are decomposers

DECOMPOSERS sunlightproducerconsumer 1consumer 2 consumer 3 decomposer

Ecological Pyramids Instead of representing trophic levels in a food web, an ecological pyramid can be used.

ECOLOGICAL PYRAMIDS Grass (10,000 kcal) Mouse (1,000 kcal) Snake (100 kcal) Hawk (10 kcal) 4 What do the big numbers represent? What does the kcal mean?

PYRAMID OF ENERGY How does a pyramid of energy compare to a food chain? sunlight FOOD CHAIN

PYRAMID OF ENERGY On what trophic level would a primary consumer appear? sunlight PRIMARY CONSUMER

PYRAMID OF NUMBERS What information would this pyramid include if it were a pyramid of numbers? How do they get a number total for a population of organisms?

PYRAMID OF BIOMASS What is biomass? What information would this pyramid include if it were a pyramid of biomass? Compare the population size of the hawk to the population size of the grass?

RELATIONSHIPS IN ECOSYSTEMS COMPETITION, PREDATOR/PREY, AND SYMBIOTIC RELATIONSHIPS Pages 39-40

Competition COMPETITION humans plants & animals Organisms living in the same place at the same time must compete for natural resources (food, water, shelter, space)

Predation Interaction in which one organism captures and feeds on another organism Predator Prey

Predation Rabbit and Coyote rabbit coyote

Ultimate Predator? Why is man sometimes called the “Ultimate Predator”?

Symbiotic Relationships There are 3 types of symbiotic relationships Mutualism Commensalism Parasitic An ecological relationship in which two or more species lives in a close, long term association

Mutualism Relationship in which both species benefits Termites cannot digest wood. Protists live in the guts of termites and digest the wood. Both are happy!!! Protozoans in termite gut Joseph Leidy lithograph, 1891 termites

Lichen – an algae and a fungus living together. Photos by permission of Steve and Sylvia Sharnoff Mutualism The algae receives protection and the fungus receives glucose.

Commensalism Relationship in which one organism benefits and the other is neither helped nor harmed.

Parasitism (Parasites and Parasitological Resources) Ticks, Fleas, Worms on a Dog: Parasite gets nourishment from the dog. The dog is harmed…may become sick from the bite or disease. Relationship in which one organism benefits and the other organism is harmed.