© Weston, 2010

ECOLOGY in 45 minutes!The diversity of life on Earth is a beautiful thing. Otherwise, what a boring world we’d have to observe around us…

#1 What’s Ecology?Ecology is a branch of biology (the science of living things). Ecology focuses on howorganisms relate to each other and their environment to survive. Ecology is the sciencehighlighted by shows you’ve probably seen on TV…

#2 Write.

Notes – Ecology & EnergyI. Ecology – the study of how organisms relate to each

other and their environments.

Write.your.name

This ecologist is prepared to collect samples that willdetermine how diverse & healthy this ecosystem is.

#3 Food Chains You’ve probably learned food chains in prior years. The thing to remember is that a foodchain shows energy flow. In other words, the arrows need to show where energy is goingto, not where it is coming from.

There are different roles in the food chain. Let’s review them here.

Question: What one object allows for life on Earth to continue on?

Did you really say that? You meant to say:

The Sun is the primary energy source for almost all food chains on Earth. The only exception is in eco-systems at the bottom of oceans near tectonic vents.

The Sun’s energy, converted into food duringphotosynthesis, is the PRIMARY ENERGY SOURCEfor all practical food chains.

#4 Producers Animals can’t do squat with the Sun’s energy for food purposes—it just warms us up andmakes us feel nice n’ toasty.

Plants have an absolutely fascinating ability to convert sunlight into sugar. Sugar CAN beuseful to animals, which is good news for everyone in the food chain (except for the plantsabout to be eaten, of course).

Plants are called PRODUCERS because they “produce” a usable form of energy from anunusable form. You may not think plants are cool and may hate eating your veggies, butyou should hug a tree or a shrub or a weed the next time you see one, because withoutplants, there’d be no animals on Earth.

#5 Primary ConsumersWhat’s it mean to consume?

Um, yeah…pretty much.

Once producers have worked their photosyntheticmagic and made usable sugar, certain animalswill be right there ready to gobble it up.

PRIMARY CONSUMERS eat plants. In otherwords, we’re talking about herbivores here.Primary means “1st” so that probably gives you ahint as to what comes next.

#6 Secondary ConsumersA grasshopper has chewed up a whole bunch of grass. Yum. Suddenly, a turkey runsover and destroys the insect with its beak, then eats it. Yum.

The turkey acts as a SECONDARY CONSUMER here. We’re talking about carnivoresor omnivores—animals that get their energy by mainly eating other animals.

Secondary consumers can then be eaten by other consumers (called tertiaryconsumers), such as if a human kills and eats the turkey in late November. Scavengerscount as secondary consumers, too—there’s no difference in energy flow if a vulture first kills a squirrel then eats it or if the vulture waits til it dies of old age.

#7 Decomposers Once a tree dies and becomes a log, or armadillo roadkill has been picked-clean by vultures, there’s bound to still be nutrients remaining in the carcass. Here’s where decomposers come into play.

DECOMPOSERS decay dead organic matter. We’re talking about fungi and bacteria. Scavengers just eat leftovers. Decomposers actually finish the process off. Decomposersplay a very important role in ecosystems, as they release stored-up nutrients in dead carcasses which get used by living plants in the area. If this helps plants get healthier,then it helps the consumers that eat the plants get healthier, and so on and so on.

#8 A Sample Food Chain

Sun

Gotta start with the Primary Energy Source.

Arrows show where energy goes to.

Seaweed (Producer) Carp (Primary Consumer)

Seal (Secondary Consumer) Bacteria (Decomposer)

Just because the bacteria take energy from the seal doesn’t necessarily implythat they killed the seal. Nope, they just had to eat it for the arrow to makesense. The seal could’ve drowned or been killed in a storm…who knows?

Moreover, if we had fit in a Killer Whale between the Seal and Bacteria, the Killer Whalewould’ve acted as a tertiary consumer in this food chain. Simple stuff, so you just needto remember the basics.

#9 Food Chain, SummarizedSun Seaweed (Producer) Carp (Primary Consumer)

Seal (Secondary Consumer) Bacteria (Decomposer)

Remember, a food chain shows the flow of energy from one object or organism tothe next.

That’s why the arrows don’t point at what gets eaten…the arrows point at what isDOING the “eating.” The arrows show where the energy goes to. The food chain inblue could be read like this:

•The Sun gives its energy to seaweed, a producer.•The seaweed gives its energy to a carp, a consumer.•The carp gives its energy to a seal, another consumer.•The seal (or carp or seaweed) gives its energy to bacteria, which decompose all the dead organisms in the area.

#10 Write!

I. Ecology – the study of how organisms relate to eachother and their environments.

II. Food Chain – a diagram showing how energy flowsin an ecosystem. Arrows show where energy goes to.

Example: Sun grass cricket chickenA. Roles

i. producers – use sunlight to produce useablefood energy (plants!)

ii. consumers – get energy by eating producers orother consumers (animals!)

iii. decomposers – break down formerly livingmatter into useable nutrients (fungi/bacteria!)

#11 Taking advantage of decomposers

How does a bird egg stay warm enough so that the chick doesn’t die of cold?

Alligators don’t sit on their eggs—they just leave‘em. So how do those eggs not die?

The mama alligator piles up leaves and twigs allabove the eggs. These no-longer-alive plant bitswill start decomposing, thanks to bacteria. As the leaves decompose, the temperature of the nest increases, which keeps the eggs at the proper temperature for development.

People can take advantage of decomposition in a similar way—not to keep our eggs warm, because most people don’t lay eggs—but rather in a compost heap. Compostdescribes storing formerly living matter (leaves & twigs, leftover food, animal manure, etc.) to let the decomposition process begin. After a while, much of this material willhave decomposed, which frees up valuable nutrients to be spread in gardens and lawns. It’s an easy way to avoid the use of harsh chemical fertilizers while helping toavoid making too much waste. More and more people are composting…will you?

#12 Write

A. Rolesi. producers – use sunlight to produce useable

food energy (plants!)ii. consumers – get energy by eating producers or

other consumers (animals!)iii. decomposers – break down formerly living

matter into useable nutrients (fungi/bacteria!)

•Compost – using decomposition to turn formerly-living matter into fertilizer

#13 Energy Pyramids & the 10% Rule

An Energy Pyramid shows the flow of and amount of energy at different levels in anecosystem. Think of it as analternate way to draw a foodchain. They almost always leave out the Sun and decomposers, and focus on theentities in the middle.

The shape of the pyramid suggests there are more insectsthan owls in this food chain.There’s more grass than thereare rodents by a lot, too. The 10% Rule describes how onlyabout 10% of the energy makes it from one level to the next. Where is the 90% of energythen? The majority of eaten (consumed) energy is lost as heat to the environment duringmetabolism—it’s not saved as stored-up energy to be eaten by the next higher-level.

#14 Write

A. Rolesi. producers – use sunlight to produce useable

food energy (plants!)ii. consumers – get energy by eating producers or

other consumers (animals!)iii. decomposers – break down formerly living

matter into useable nutrients (fungi/bacteria!)

•Compost – using decomposition to turn formerly-living matter into fertilizer

B. Energy Pyramid – diagram that shows much more energy exists early in food chain. Less isavailable for consumers at the end.

#15 Add a sample Energy Pyramid

SUNLIGHT ENERGY

Energy in Producers

Energy in Consumers

This type of energy pyramid describes what you may have noticed while watching nature shows on TV.

In this picture, what is the most abundanttype of living things?

PLANTS!

Then there are lots of herbivores, andvery, very few top predators.

For every lion or cheetah in Africa, theremay be hundreds of zebra or wildebeest.That’s the energy pyramid.

#16 And That’s…