Ecology Series One

e

Robert Perry Malibu High

P r esen t s

cology basics Series One

INTRODUCTION TO ECOSYSTEMS

What is ecology ?

ECOLOGY is a branch of biology that studies ecosystems.

Continued on next page---->

What is an ecosystem ?

An ecosystem is an interelated system that includes all the autotrophs, heterotrophs, and the physical and chemical factors of the environment at a given place and time.

What is an ecosystem ? autotrophs

heterotrophs

environment

What is an ecosystem ? autotrophs

heterotrophs

Arrows show a transfer of:

environment

What is an ecosystem ? autotrophs

Arrows show a transfer of: ENERGY

heterotrophs

environment

What is an ecosystem ? autotrophs

Arrows show a transfer of: ENERGY & MATERIALS

heterotrophs

environment

WHAT DO SCIENTISTS KNOW ABOUT HOW

_ENERGY_ BEHAVES ?

ENERGY the Laws of Thermodynamics !

The First Law of Thermodynamics:

ENERGY cannot be created or destroyed, only changed from one form to another.

meaning: 1- The total or net amount of ENERGY in the universe is constant.

2- ALL living organisms must have an outside source of ENERGY since they cannot “create� it.

The Second Law of Thermodynamics:

ENERGY tends to spontaneously degrade. useable (. . .from a concentrated form to a dispersed form.) useless

meaning: 1- The amount of useable ENERGY for living organisms is always going DOWN, down, down.

2- ENERGY is degraded to HEAT.

WHAT ARE...

CONCENTRATED FORMS OF ENERGY ?

Light Electricity DISPERSED FORMS OF ENERGY? Heat

What is an ecosystem ? (in terms of ENERGY ! ) A series of controlled ENERGY transformations between in-coming LIGHT and out-going HEAT.

The 3-Step ENERGY PATHWAY THROUGH AN ECOSYSTEM.

ENERGY !

ENERGY in the ecosystem True, dat...

BEGINS WITH SUNLIGHT

THE SUN GIVES OFF

MANY FORMS OF ENERGY.

noon

10 am

2 pm

ocean surface

Time of day determines the amount of sunlight that gets past the surface.

ocean surface

Water molecules selectively absorb wavelengths !

The 3-Step ENERGY Pathway

OS

YN TH ES IS

1.

PH OT

LIGHT

photosynthesis CO2 + H2O

C6H12O6 + O2 chemical energy

OS

YN TH ES IS

1.

PH OT

TI O

N

CHEMICAL ENERGY 2.

R ES PI R A

LIGHT

respiration chemical energy

O2 + C6H12O6

CO2 + H2O ATP (work for cells)

HEAT

R ES PI R A

TI O

CHEMICAL ENERGY 2.

N

YN TH ES IS PH OT

1.

OS

LIGHT

HEAT 3.

ENERGY IS GREAT… BUT WHAT ABOUT

MATERIALS !? (aka chemicals, or matter)

environment

<---------

IN

<---------

<---------

<---------

PHOTOSYNTHESIS + solar CO2 + H2O ---------> C(H2O) + O2 energy RESPIRATION + energy CO2 + H2O <--------C(H2O) + O2 for cell OUT

organisms

REVIEW CHECKPOINT:

CHEMICALS ___________ MUST be recycled.

FERTILIZERS essential for life are in short supply and must be re-used.

Examples: Sulfate Nitrate

SO4

NO3

on land

in ocean

Phosphate Silicate

PO4

SiO2

REVIEW CHECKPOINT:

E N E R G Y ___________ cannot ever be recycled.

REVIEW CHECKPOINT:

WHY?

The Second Law of Thermodynamics:

ENERGY tends to spontaneously degrade. (. . .from a concentrated form to a dispersed form.)

End of first seriesâ&#x20AC;Ś.