ECOLOGY AND ECOSYSTEMS

Ecosystem

•Includes abiotic and biotic factors

•Biomes are examples

Communit

y

•Includes all the LIVING things

Population

•All of one species in one area

•Can reproduce with each other

FOOD CHAINS

Original source of energy for most chains is the sun

1st trophic level is producer

2nd trophic level is primary consumer

2rd trophic level is secondary consumer

Decomposer not shown on chain, but they recycle nutrients

Secondary Consumer

(bird)

Primary Consumer(snail)

Producer(grass)

Energy is “lost” as you mover “up” the food chain

SYMBIOSIS

Mutualism• n mutualism, BOTH

organisms BENEFIT• this is a + / +

relationship• The picture shows E.

coli, a type of bacteria that live in your intestine. 

• The bacteria get a place to live; we get the vitamin K they make.  This is good for both.

Parasitism• In parasitism, the

PARASITE BENEFITS by getting food and shelter from the HOST

• This is a + / - relationship

• In the example shown, the TICK is the parasite and feeds off of the blood of the human HOST.  This is good for the tick, but bad for the human.

Commensalism• In commensalism, one

organism BENEFITS while the other is NOT AFFECTED

• This is a  +/ 0 relationship

• The picture above shows orchids living in trees.  This is good for the orchid, because it allows the orchid to get sunlight. It doesn't affect the tree, because the orchid doesn't help or hurt it.

PREDATION

• Predator EATS Prey

• The populations cycle

• Predator has lower curve• There can’t be more predators

than prey

POPULATION GROWTH

E X P O N E N T I A L G R O W T H

J-curve

Occurs when unlimited resources are available

L O G I S T I C G R O W T H

S-curve

Occurs because resources are limited

Carrying capacity reached

HUMAN POPULATION GROWTH

Overpopulation of humans leads to

• Destruction of habitats (pollution and/or destroying)

• Loss of biodiversity

• Introduced species•Outcompete nativespecies

CARBON CYCLE

• Cycling of carbon and oxygen

• Three main processes• Photosynthesis – plants use carbon dioxide; produce oxygen• Respiration – uses oxygen, produces carbon dioxide (both plants

and animals)• Combustion – burning – releases more carbon dioxide

Greenhouse Effect• Carbon dioxide traps heat

in the atmosphere, making life possible

• Increased carbon dioxide can make temperatures rise more

• Human activities can lead to GLOBAL WARMING

BE A GOOD STEWARD