Energy Flow in Ecosystems How do organisms obtain energy/food? –Autotrophs – make their own food Usually by photosynthesis (light to make food) Also called “producers” What are some examples?

Energy Flow in Ecosystems How do organisms obtain energy/food? –Heterotrophs – must “get” food Consumers – eat organisms –What are some examples? Decomposers – decay & absorb food –What are some examples? Detritivores – eat dead material –What are some examples?

Trophic Levels

In your own words, on page 11, define the following terms: Abiotic Biotic Habitat Niche Autotroph Heterotroph

Energy Flow in Ecosystems Why do we continually need food? –Cells need energy to do work –Food energy moves through ecosystems when organisms eat others –Ultimate source of energy is the sun

Energy Flow in Ecosystems What path does energy usually follow? Sun  Autotrophs  Heterotrophs Decomposers & detritivores eat/decay wastes & dead stuff

Food Chains Show who ate who Arrow points to where energy goes

Energy Flow in Ecosystems Is that the only path energy may follow? – No! all of the food chains put together form a food web

Energy and Ecosystems

In your own words, on page 11, define the following: Producer Consumer Herbivore Carnivore Decomposer Biome

Energy Flow in Ecosystems How can ecosystem energy be shown? –Ecological pyramids show relative amts of organisms in an ecosystem –Each step up has less energy available & fewer organisms –Each step involves losing energy to heat…only a small % of energy actually gets transferred

Energy available at each level is reduced from the previous… Why?

Energy and Ecosystems

Energy Pyramid How much energy is from the sun for each trophic level? Only about 10% energy is moving to the next level… Most of the energy is actually lost in the form of heat. This makes it non-efficient! So the higher the level, the more of the lower level they have to eat to have enough to feed its cells! The lack of efficiency can be shown with diagrams call the energy pyramid

Questions on Page 8 With your table, answer the questions about the energy pyramid! We will discuss this as a class Afterwards, a demo will be shown to show the energy flows

Nitrogen and Carbon Cycles

Cycling of Nutrients: Carbon Cycle

Cycling of Nutrients: Nitrogen Cycle