No warm-up in your lab book…I’ll give you a separate paper I’ll initial your Isle Royale conclusion while you work

Warm-Up 4.21 and 4.22 Label the provided map with your partner. At each point, explain what you think is going on with the populations!

Warm-Up Conclusions There is usually a peak in wolf population after a peak in moose population (because the wolves have more food and can reproduce better) When wolves eat the moose, the moose population goes down When the moose population goes down, the wolf population follows because they don’t have enough food to eat With less wolves, the moose reproduce and grow again. The cycle continues!

Lynx and Hare Relationships Let’s continue to model this predator-prey relationship with our Lynx and Hare Lab! Find your blue handout and get two baggies of creatures + a whiteboard You can either start over or pick up where you left off Do the graphing and analysis, too!

Yeast Lab Data Collection Collect data on both test tubes using a microscope, pipette, slide, and cover slip Done? Rinse off your slide and cover slip and put them back in the beaker at your station. Throw the pipette away.

What do Ecosystems Need? For ecosystems to thrive, its members need energy and matter Matter = liquid, solid, and gas ‘stuff’ Ex: water, CO2, nitrogen, sugar Let’s explore first where ecosystems get their energy…

Energy for Ecosystems The sun provides the initial energy for ecosystems Plants harvest sunlight and turn light energy into chemical energy (glucose) This is called photosynthesis CO2 + H20 + light glucose + O2 In an ecosystem, we call plants producers

Energy for Ecosystems Chemical energy (glucose) stored in plants is passed on to herbivores, which eat the plants Chemical energy in herbivores (protein, fat, sugar) is passed on to carnivores, which eat the herbivores This forms a food chain. Many food chains together form a food web.

Quick Vocabulary Carnivores eat animals Herbivores eat plants Omnivores eat both

ENERGY ALWAYS FLOWS THE SAME WAY THROUGH AN ECOSYSTEM: Sun Producers Consumers Energy does not recycle. It is lost as heat when organisms burn it off!

Drawing a Food Chain In a food chain and web, arrows point in the direction of energy flow, not who eats who Ex: Grass Cricket Draw a food chain in your notes with the following info.: Caterpillars eat rhododendrons Bluejays eat caterpillars Cats eat bluejays Bears eat cats

Draw a food web Now add this information to your chain to make a web: Cats eat mice Mice eat dandelions Caterpillars eat dandelions Cougars eat cats and mice

Players in the Food Web Plants are called producers, and also autotrophs Autotroph = makes own food using sunlight First level consumers eat producers Second level consumers eat first level consumers, and so on Consumers are also called heterotrophs (get food/energy from outside source) On your food web, label the producers with a ‘P’, first level consumers with a ‘1’, second with a ‘2’, and third with a ‘3’.

Other Players Detritivores (mites, snails, and worms) feed on dead matter Decomposers (bacteria and fungi) break down dead matter

Food Web on Isle Royale Using the information on pages , make a food web for Isle Royale, including EVERY ORGANISM mentioned. Fill up the whole provided paper, and do your work neatly.

Add to your diagram… 1. Label producers with a “P”, first level consumers with a “1”, second level consumers with a “2”, and so on 2. In YELLOW, trace the flow of energy from the sun, through one food chain, to heat given off

Due Next Time… Finish blue Lynx/Hare Lab

Last Slide 4.21

Energy Pyramids The energy that producers and consumers can possibly make and pass on can be represented in an energy pyramid Because producers photosynthesize and are numerous, they are on the bottom of the pyramid

Pyramid of Energy Example

10% Rule in Ecology Only about 10% of the energy in one trophic level is passed to the next trophic level.

10% rule... 10% 90% lost as heat

10% rule diagrams... 10% 90% lost as heat

10% rule diagrams... 10% 90% lost as heat

How much energy is at each level? 1000 Cal ? Cal

How much energy is at each level? 1000 Cal 100 Cal 10 Cal 1 Cal 900 Cal as heat 9 Cal as heat 90 Cal as heat

3 Reasons for 90% loss of energy 1. Energy is “used up” for daily needs of the organism (respiration) 2. Not all organisms in a population are eaten by animals in the next level. 3. Not all parts of an organism are eaten and digested for energy.

More on Cellular Respiration The molecules eaten by consumers (proteins, fats, sugars, DNA) are rearranged into more useful substances in cells The sugars are converted to ATP, a tiny energy molecule, by cellular respiration Extra energy is given off as heat! C 6 H12O 6 + O2 CO2 + H2O + ATP

Dude, put a shirt on…