Ecology: Community Interactions

Food Web Notes/2.0: Energy and feeding relationships! Terms to know…..

Producers A group of organisms that can use the energy in sunlight to make food. Energy for all ecological systems begin with producers. Also called Autotrophs Ex. Plants and Algae

Autotrophs

Consumers Organisms that do not make their own food They must consume other organisms in order to live. Also called heterotrophs.

Heterotrophs

Herbivores Consumers – 1. Herbivores – eat ONLY plants Ex. – Cows, Elephants, Giraffes

Carnivores Consumers – 2. Carnivores – eat ONLY meat Ex. – Lions, Tigers, Sharks

Predator/Prey Interactions

Omnivores Consumers – 3. Omnivores – eat BOTH plants and animals Ex. – Bears and Humans

Decomposers Consumers – 4. Decomposers – absorb any dead material and break it down to return nutrients to the earth. Ex. – Bacteria and Mushrooms

Trophic (energy) Levels Energy moves from one organisms to another when it is eaten. Each step in this transfer of energy is know as a trophic level – The main trophic levels are producers, consumers and decomposers Food chains show how energy moves from one level to another. Arrows show energy flow.

Transfer of Energy When a zebra eats the grass the energy in the grass moves to the zebra. When a lion eats the zebra the energy from the zebra moves to the lion.

Food Chains A food chain is simple and direct It involves one organism at each trophic level.

Food Chain

Food Web Most organisms eat more the JUST one organism! When more organisms are involved it is know as a FOOD WEB. Food webs are more complex and involve lots of organisms.

Food Web examples

Food Web Questions (IN YOUR NOTES) Look at the food web to answer the following questions: 1.Are the plants usually at the bottom or the top of the food chain? If they do not eat, where does their energy come from? 2.Do the arrows point to the eater or the organism being eaten? 3.The arrows show how ENERGY moves. Where does the energy in a community start? 4.The energy decreases at each level. Which group of organisms have the most energy? Which group of organisms have the least energy? 5.8 minutes.

Transfer of Energy No organism EVER receives all of the energy from the organism they just ate. Why? – Energy is lost as heat – Not all of the organism is eaten Only 10% of the energy from one trophic level is transferred to the next – this is called the 10% law As energy moves through a food web it ________________.

Food Web Activity / 2.0

Ecological Pyramid

5. Which level has the most energy? 6. Which level has the most organisms? 7. Which level has the least organisms? 8. Which level has the least energy?

Food Web Activity Complete Part B of the Food Web Activity – 15 minutes

Food Web Questions (IN YOUR NOTES) Look at the food web to answer the following questions: 1.Are the plants usually at the bottom or the top of the food chain? If they do not eat, where does their energy come from? 2.Do the arrows point to the eater or the organism being eaten? 3.The arrows show how ENERGY moves. Where does the energy in a community start? 4.The energy decreases at each level. Which group of organisms have the most energy? Which group of organisms have the least energy? 5.Popsicle sticks for answers.

Symbiosis A close and permanent association between organisms of different species (not predator /prey) Chart – Commensalism – a relationship in which one organism benefits and the other is not affected Example: Barnacles on a whale – Mutualism – a relationship in which both organisms benefit from each other Example: Birds eating pest off a rhino’s back – Parasitism – A relationship in which one organism benefits and the other is harmed Example: Ticks on a dog

Cycling through the ecosystem 1. Water Cycle – 4 –tions: evaporation, transpiration, condensation, precipitation – Powered by the Sun – Abiotic Cycle

Carbon Cycle 1.Write the equation for photosynthesis. Circle Carbon. 2.Cards Activity 1.Match the pictures on the cards with the appropriate description. 2.Separate them into a ‘sink’ row and a ‘source’ row. 3.Create a chart on your paper and list them under the correct column. SourcesSinks 4. Circle all of the cards that are directly affected by humans.

Cycling of resources in an ecosystem. 2. Carbon Cycle Write the equation for photosynthesis. Write the equation for respiration. – How does carbon ENTER the atmosphere? – How is carbon REMOVED from the atmosphere? – Biotic Cycle

Carbon

Cycling of resources in an ecosystem. 3. Nitrogen Cycle All living things need nitrogen! Lots of nitrogen is available in the air but plants cannot take it in. Bacteria in the soil or on roots create usable nitrogen for plants. Animals eat plants Death and decay puts nitrogen back into the air. Biotic Cycle

Diagrams Paste both diagrams in your notebook with the notes. On the Carbon Cycle: – Color the arrows that PUT Carbon Dioxide into the air RED. – Color the arrows that TAKE Carbon Dioxide out of the air GREEN. – What parts of the Carbon Cycle would not have been present before the Industrial Revolution?

Color ONE of the cycles on your sheet. WaterCarbonNitrogen Into the atmopshere Out of the atmosphere Biotic or Abiotic Important Organisms

Predator/Prey Interactions ( Homework Sheet)

Cycling of resources in an ecosystem. Water Cycle – 4 –tions: evaporation, transpiration, condensation, precipitation – Abiotic Cycle Carbon Cycle – How does carbon enter the atmosphere? – How is carbon removed from the atmosphere? – Biotic Cycle Nitrogen Cycle – Bacteria in the soil or on roots create usable nitrogen for plants.

Biomass The total mass of the organic matter at each trophic level is called biomass Biomass is just another term for potential energy – energy that is to be eaten and used. The transfer of energy from one level to another is very inefficient (10% Law)

Biomass

Ecological Pyramid An ecological pyramid shows the relationship between consumers and producers at different trophic levels in an ecosystem Shows the relative amounts of energy or matter contained at each trophic level The Pyramid shows which level has the most energy and the highest number of organisms