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.