Unit 2 Ecology

“Big Idea” What do living things need in order to do all the things that make them alive? Living things need to obtain & use energy in order to do work! Bioenergetics – the study of the energy flow & transformations among living things Ecology – the study of how living things interact with their environment ◦In order to get stuff like food (aka energy)

 Eat!  What do we call the energy in our food?  Calories  Measure the amount of energy stored in your food  Where is the energy stored in your food?  In the molecules that are bonded together to make that food. chemical energy  Called chemical energy!

 When you break a bond…  You release energy!  Decomposition  When you make a bond…  You store energy!  Synthesis

 Basically 2 ways living things get this energy…  Heterotroph  Obtain energy from other living things.  AKA  EAT  Cellular Respiration  Autotroph  Use surrounding to make their own food!  Plants  photosynthesis  Bacteria  chemosynthesischemosynthesis

 Would a deer come running out of the woods and try to eat you? Why?  Organisms have certain roles!  Autotrophs – producers  Heterotrophs – consumers  Special Case – Decomposers (consume dead matter)  Bacteria, fungi, worms, vultures  Recycle important nutrients back into soil for producers such as plants to use again

 If you eat plants (herbivore) you are a primary (1 o ) consumer  If you eat herbivores (carnivore) you are a secondary consumer (2 o )  If you eat 2 o consumers then you are a….  Trophic Levels

Food Web  More Realistic than chain  Display the flow of energy through an ecosystem Arrow points in the directions the energy is traveling!  Ecosystem – all the living & nonliving things in an area All Living Things – Biotic Factors All Non Living Things – Abiotic Factors

The Re-Introduction of Wolves  Go to page 95 in your textbook & read “The Wolf Effect” Then…  Use the food web on the handout, and answer question 1.

The mouse population would most likely increase if what happened? What would cause the mouse population to decrease? Using this information, why do you think we have such an overpopulation of deer in New Jersey?

More Vocab…  Habitat – places where particular organisms live  Niche - organism’s role in its environment Niche -

Organization/Levels of Nature Biomes

Laws of Thermodynamics  Study of Energy Changes  1 st Law – energy cannot be created or destroyed, but it can change forms. ○ Law of conservation of energy

What does the 1 st law mean for living things?  Living things can not create their own energy, they must obtain it from their environment!  Amount of usable, available energy is always decreasing in an ecosystem because it is being turned into other forms of unusable energy (heat).  Relate to food web/food pyramid  need more autotrophs to support a smaller number of heterotrophs  Why it looks like a pyramid!

2 nd Law entropy!  Systems tend to change in a way that increases disorder or entropy!  What does this mean for living things?  Organisms must be well organized to remain alive & grow!  Use energy to fight against entropy to maintain homeostasis!

Energy terms & calculations! Biomass – dry weight of all organic matter contained within a trophic level (grams/kg) Energy stored in biomass is transferred from 1 level to another (only about 10%) – What happens to the rest of it? Lost as heat energy or other unusable form

Put this information all together! Using what you have just learned, why can’t trophic levels go on forever (4,5,6 level consumers)? Why is there a one way flow of energy in ecosystems? Where does the energy at the bottom always have to come from?