Almost all energy on Earth comes from the sun. Energy Flow Almost all energy on Earth comes from the sun.

Sun Main energy source Photosynthesis

Producers Autotrophs Perform Photosynthesis or Chemosynthesis Bacteria Algae Plants

Photosynthesis Light energy into carbohydrates Produces O2

Chemosynthesis Use energy in chemical bonds to produce carbs Found – no light present

Consumers Acquire energy from others by eating AKA:Heterotrophs

Six Types of Consumer Carnivore Herbivore Omnivore Consumes other animals Consumes plants Omnivore Consumes both plants and animals

Six Types of Consumer Scavenger Decomposer Detritivore Breaks down Organic material Detritivore – feeds on dead plants Consumes dead and decaying organic matter

Energy Relationships

Environment producers consumers  decomposers. Food Chains One-way energy flow Environment producers consumers  decomposers.

E N R G Y Trophic Levels Producers- Autotrophs Secondary consumers Tertiary consumers- top carnivores Secondary consumers Primary consumers - Hetertrophs Producers- Autotrophs 12

Food Chains Series of steps in which organisms transfer energy from eating or being eaten Arrows point towards consumer

Food Web Network of complex interactions formed by feeding relationships among the various organisms in an ecosystem

How does energy move through a food web How does energy move through a food web? All the food chains in a habitat are put together in a food web to show how the food chains overlap. Energy starts with the sun, then goes to plants and then consumers. Amoeba sisters video in picture

Great Blue Heron Frog Crab Overharvesting depletes most of the crab population. What changes in this food chain?

What do the solid arrows represent? What do the dashed arrows represent? Can you trace a food chain from one of the producers to the bobcat? Why is a food web a more accurate representation of feeding relationships in an ecosystem than a food chain? Even though only one organism is shown in the food web, it represents all the individuals of the species.

Ecological Pyramids Shows the relative amount of energy contained within each trophic level in a food chain

Trophic Levels Trophic – Greek “trophe” Producers= 1st trophic level Food or nourishment Producers= 1st trophic level Consumers= 2nd level and higher

Trophic Levels Read from the bottom to the top of pyramid 1st trophic level- producers/autotrophs Ex: Plants 2nd trophic level- primary consumers Ex: Herbivores or omnivores 3rd trophic level- secondary consumers Carnivores or omnivores 4th + trophic levels- tertiary or quad consumers Ex: top predators- carnivores

Types of Pyramids “The 10% Rule” 1. Energy Pyramids 10% energy transferred up to next level as organisms feed on one another. The rest is lost as HEAT. “The 10% Rule”

Types of Pyramids 2. Biomass Pyramids Biomass – total amount of organic matter present in a trophic level

Number of organisms at each trophic level. Higher # at LOWER levels. Types of Pyramids 3. Pyramid of numbers Number of organisms at each trophic level. Higher # at LOWER levels. http://www.harcourtschool.com/activity/science_up_close/314/deploy/interface.html

Biomagnification Video on Marine mercury in picture

Biomagnification The process by which toxic substances accumulate at increasingly high concentrations in progressively higher trophic levels

Two Characteristics Non Biodegradable Fat soluble Accumulate in fat of body Bioaccumulation Stored energy is passed to higher trophic levels

DDT - Pesticide Dichloro – Diphenyl – Trichloroethane Use in WWII to control malaria After war – agricultural insecticide 1972 – Banned in US

Bald Eagle DDT affected offspring Affects not seen initially Caused by DDE (broken down DDT) Blocks calcium carbonate production Resulting in egg shell thinning Affects not seen initially

Shell Thinning