THE BIOSPHERECH. 3

I. ECOLOGY IS:THE INTERACTIONS OF BIOTIC WORLD WITH THE ABIOTIC WORLD.

•ABIOTIC - “PERTAINING TO THE NONLIVING WORLD.”•EX. ?

•BIOTIC - “PERTAINING TO THE LIVING WORLD.”•EX. ?

ECOSYSTEM -•“Where the abiotic meets the biotic.”•Ex. - your backyard, campus, neck of a dog….&•Nemo’s backyard!!!

II. Biotic Parts of an Ecosystem

A. Producers/ autotrophs …

B. Ex…

EXCEPTION TO THE RULE!!!

•SOME AUTOTROPHS CAN “MAKE FOOD”

WITHOUT LIGHT.•CHEMOSYNTHESIS IS THE

USE OF INORGANIC COMPOUNDS

SUCH AS HYDROGEN SULFIDE TO MAKE FOOD FOR ENERGY.

•B. Consumers/heterotrophs …

Types of consumers:Primary consumers

(Herbivores)Secondary cons.

(Omnivores)Tertiary cons.

(Carnivores)

C. DecomposersPrimary Detritivore –

Feed on detritus – dead plants/animals, fecal

wastesEx. Earthworms, bacteria,

fungi

Secondary detritivore – feed on Prim. Detritivore

Ex. Millipedes, insect larvae

So the order is.... Prod. --> Prim. Cons. -->

Sec. Cons. --> Tert. Cons. --> Decomp. --> Prod..........

And everything repeats!!

Food Chain - indicates a single flow of NRG through the ecosystemEx. ?

Food Web - indicates the flow of NRG throughout the entire ecosystem

Figure 3-8 A Food Web

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III. Energy Pyramid Shows “how much” nrg and nutrients are available in the ecosystem.

“Big at the bottom!Small at the top!!”

The available amount of nrg

decreases as it “moves” up to the top. Each level is called a trophic

level. Most of the nrg is lost as heat.

Biomass pyramid shows-

total weight of all organisms at each trophic level.Decrease is because much of the biomass is:

–used as NRG, instead of becoming tissue, &

–Broken down by decomposers.

IV. What Shapes an Ecosystem?

•The interaction between: a. abiotic factors,

b. biotic factors, & c. abiotic & biotic

factors together.

A. Habitat - “where an organism lives”

–Ex. Pond, under a rock, on tree bark...

B. Niche - “what an organism does”

Ex. Eats leaves, feeds on dead animals...

Organisms, whether the same or different, must interact within their ecological community.

This is Symbiosis.

V. Symbiosis - “pertaining to living together”1. Mutualism - both are

benefitting.

Ex. ??

2. Commensalism - one benefits &

one gains nothing. Ex. ??

3. Parasitism - one benefits (parasite) & one is harmed (host)

Ex. ??

Tomato hornworm & wasp pupae

4. Competition - two or more organisms competing for limited resources.

Ex. ??

The End!!

5. Predation - one being “chased” & one doing the “chasing”

Ex. ??