Our Ecosystem The Circle of Life Ecosystem All

Our Ecosystem…. . The Circle of Life

• Ecosystem…. • All of the biotic (living) and abiotic (non-living) factors in an area and the organisms within that system

Organisms in the Ecosystem • In an ecosystem, each organism has a… • Habitat = where an organism lives, its “address” • Niche = what an organism does, its “job” • Trophic Level = energy or feeding level

Trophic Levels • Producers • Produce their own food • Ex: plants, trees, flowers…. • Primary Consumers • Eat the producers • Ex: rabbits, deer, cows, chickens • Secondary Consumers • Eat the primary consumers • Ex: humans, fox, salmon

Trophic Levels cont…. • Tertiary Consumers • Eat secondary consumers • Ex: sharks, bears, hawks • Scavengers • Eat something someone else killed • Ex: crows, vultures, hyenas • Decomposers • Eat dead material (detritus) • Ex: bacteria, fungus, worms

You are what you eat…. • Autotrophs • Make their own food within itself • Ex: plants

Heterotrophs • Organisms that cannot make their own food must eat something • Herbivores • Eat only plants • Carnivores • Eat only animals • Omnivore • Eat both plants and animals

Energy Flow in an Ecosystem • All energy in an ecosystem comes from the sun • This energy then will move up through the various trophic levels • An ecological pyramid shows the relationship between producers and consumers at different trophic levels in an ecosystem

The Tropic Level Pyramid

The 10% Law • As you go up each level of the energy pyramid, 90% of the energy is lost! • Only 10% is actually transferred from one level to the next!! • The energy is either lost as heat or not eaten/digested…therefore this energy cannot be transferred on to the next level.

Just another look

Showing Energy Transfers • We can use food chains and food webs to show the series of steps through which energy is transferred • Food Chain = a single pathway of food and energy through a community • Food Web = a series of interconnected food chains • The arrows must point in the direction that the energy is being transferred • IOW…it points to who is doing the eating

A Food Chain Jay

Review • What is a habitat? • Where an organism lives. • What is a niche? • An organism’s job • What is an autotroph? • An organism that can make its own food. • What are the 4 trophic levels? • Producers, primary, secondary, tertiary consumers • What is a food web? • An interconnected series of food chains

Any Questions? ?