Transcript lecture 9/16, ecology II

ES101 9/16/10
Ecology II
Tutor – HIGHLY RECOMMENDED!
Frangelica Odell, M&W, 6-8pm, MH201
• Turn in reading questions (with sect #)
• Students in Fri lab, be prepared
for rain showers
• Assessment Survey
ES101 9/16/10
• Assessment Survey
• DOES NOT AFFECT YOUR GRADE!
• We will use it in June to assess
the effectiveness of the course
Terrestrial Biomes of
the World
Biome =
Dominant ecosystem
in a region
Type of biome depends on
temperature & precipitation
ADD FIG. 5.1
Temperate Deciduous Forest
• Major biome in
eastern US
• Med. precipitation
• Very good soil
• Forest re-grows easily
• In general, greater
diversity than
forests further north
• Why are most trees
to the south decid?
• Leaves drop in
autumn because it
takes less energy to
grow new leaves
(in the spring)
than to protect
leaves from the cold
• Long enough
season, good
enough soil to do
this
• Long enough season,
good enough soil to
do this
Why are most trees to
the north evergreen?
• Evergreen needles Adaptation to cold
temps., poor soil:
Too cold, poor soil, can’t
drop leaves and grow
back in spring
Nature works like a system
• System: Set interactions among
interdependent parts
• Closed system: Isolated from outside
• Open system: Energy and materials flow in
and out (nature)
http://www.wrh.noaa.gov/tfx/hydro/FAW/ManyGlacierSmall.png
Systems are controlled by feedback loops
• Positive feedback: Increase in one process
leads to further increase
(I recommend drawing this diagram)
Temperature
increases
+
Earth
absorbs
more heat
+
+
Snow, ice
melt
Earth gets
darker
+
• Negative feedback loops:
An increase in a process eventually leads to
a decrease in that process
(drawing this diagram optional)
Temp.increases
-
+
Temp.
decreases
Clouds
reflect light
+
More water
evaporates
More
clouds
form
+
Nature works like a system
• Open system: Energy and materials flow in
and out (nature)
• Ecosystems are controlled by flows of energy
and matter
• Disturbances may alter these flows so
species cannot survive
• Disturbance = ?
• Periodic, destructive events
http://www.wrh.noaa.gov/tfx/hydro/FAW/ManyGlacierSmall.png
Will this ecosystem recover from this
disturbance? To predict, we need to know how
it works!
Bitteroot National Forest MT
Matter and Energy
• Matter = anything that has volume and mass
• Energy = ability to do work
• Kinetic energy (k.e.) = energy in anything that
moves (includes light waves, heat, etc.)
• Potential energy (p.e.) = stored energy
• Chemical p.e. = energy stored in the bonds of
molecules
• Gravitational p.e. =
energy stored in something that can fall
http://img186.imageshack.us/img186/4171/anvil1cq2.gif
http://www.retrothing.com/2008/11/acme-company-fr.html
Laws of Thermodynamics
The first law of thermodynamics states:
1. energy is destroyed
when it is burned
2. disorder in the
universe is
increasing
3. energy cannot be
created or destroyed
4. plants create energy
66%
13%
1
13%
2
9%
3
4
The second law of thermodynamics states:
1. energy is destroyed
when it is burned
2. disorder in the
universe is
increasing
3. energy cannot be
created or destroyed
4. plants create energy
52%
30%
17%
0%
1
2
3
4
Laws of Thermodynamics
• Thermodynamics = how energy is transferred
• First Law: Energy is conserved = can’t create or
destroy energy
• Can move it around and change forms
(kineticchem. p.e., etc.)
Food = Chem. p.e.
Food + oxygen = releases stored energy
Allows motion in body = Kinetic p.e.
http://themostawesomeststuffever.blogspot.com/2008/07/happy-fourth-of-july.html