Disclaimer:
These notes are my personal notes. The course instructor or TAs have
no responsibility for the contents or any discrepancies between the materials
presented in the classroom and these notes. You cannot use or refer to these
notes to support or defend your answers on your exams. I suggest you use these notes
to complement your own notes, and not to solely rely on.
I would appreciate your feedback on any part of these notes that I
may be misunderstanding.
Ø Reading for Mar 27 (Tue): Estuarine
Ecology (Day, Hall, et al. 1989) Chapter 1 & 2 (and 3 if you are into
estuarine chemistry: focus on the beginning and the end).
1.
The reading, Self Organization and Maximum Empower (H.T.Odum)
2.
Estuarine ecosystem
What is the
opposite of self-design?
How would we view
the ecosystem was designed 100 or 200 years ago? – created by God.
How do we view
the ecosystem was designed now? – by God, by natural selection, or by both?
Antithesis of
self-design is design by higher being of whatever we believe.
If by God, which
most educated people believed 200 years ago, what would they view the
objectives of ecosystems? – to satisfy human needs?
If ecosystems
and our function as humans is to glorify God, ….if it was determined by an
outside force, or God, then he had gone through enormous amount of trouble to
make it look like it happened over a very long time span and according to
organic revolution as we understand now. – Dr. Hall
Indian’s view of
nature:
Ø Sun = father, the earth = mother. All the
species – plants and animals – are consequence of the union of sun and the
earth.
Ø There’s hierarchy of animals – bear at
the top, eagle the second, etc., with human somewhere in the middle.
Science is
incredibly powerful. Science is good because it’s expected to be chipped out.
If God didn’t
design the ecosystems, how are systems developed? Think about it using Bernard
Cell example.
Bernard
Convection Cells (BC)
What’s BC and
what’s special about BC in this context? What does a BC do?
What does the
structure of BC do to the rate of energy?
Ø BC is a mixture of salt, slurry
Ø Dissipate the energy, turning to sensible
heat = low temp, no good for useful work
Ø Structure of BC maximize of generation of
entropy.
What is entropy?
– absence or inverse of organization.
Ø Our body is highly organized. Elements are concentrated in our body. You
will eventually go toward entropy in the absence of energy input.
Ø You are a system that intercepts energy
and generate order.
Ø BC is a system that intercepts energy and
maintains order. It reduces the rate at which input of energy is dissipated
into energetically useless heat by by generating its own structures.
(Ben)What
happens to BC at low heat? – heat goes up to certain level.
(Ben)What happens
at medium heat? – heats up the bottom, particle goes up, as it cools down it ,
cycle back down to be heated up again. Aintain hgh gradient and develop
structure.
(Ben)What
happens at high heat? – break down of structure – boil.
(Ben)BC is an
autocatalytic feedback = self reinforcing pathway.
(Ben)Example:
the relation between plant leaves and roots. More leaves -> more roots ->
more leaves ->…
(Ben)End goal of
structure is organizing itself to maximize power.
(Ben)BC
organizes itself = principle of maximum power, where it trys to maximize flow
of useful energy.
(Ben)Low heat
doesn’t’ have energy to do work.
(Ben)Medium heat
– generate structure with feedback which maximize the flow of energy.
Is maximizeing
flow energy a feedback between BC and the burner?
How does this
feedback work in the ecosystem? Ecosystem influences the sun burns? – it
maximizes the portion of energy they get?
Hour glass
example
Ø Universe is an hour glass. Sand in the
upper room has more energy, sand in lower room is entropy.
Ø Life evolved to stick a paddle wheel .
Does this
tapping slow down the flow of energy? – No.
What is the
purpose of structure (life)?
What is the purpose of life - “existential game, the purpose of which is to keep playing”
Does ecosystem
operate to maximize its capture of power? – Ecosystems organize themselves to
maximize input of energy.
What is
maintaining organization?
It appears
ecosystems, given constraints of water or temp, attempt to put our optimal
number of leaves to maximize net capture of sun.
Without what
another component ecosystem does not work? – decomposers, mineralizers.
Otherwise all the nutrients would be tied with necromass.
What’s the role
of animals? Are they merely exploiting energy?
What’s the
criteria by which an organism will exploiting resources or not?
Ø They have to have energy gain. Ex. Tiny
marine snow - nobody exploits because
cost of exploiting this resource is too high.
Ø Lake Michigan example:
§
In 1968,
huge windrow of dead alwifes. Water turned from green to blue.
§
Construction
of a canal from the ocean to the lake introduced lamprey eel.
§
Phosphorus
input from surrounding communities. More eutrophic. -> 3 billion dol. spent
to remove P.
§
Lamprey
parasitized lake trouts and killed.
§
Lake trout
feeds on alewife, which feeds on zoop, which feeds on phyto.
§
Lake trout
gone -> alewife incr. -> zoop decr. -> phyto incr. -> algal bloom
-> oxygen depletion -> fish kill.
§
The cause,
which apparently was P input, was actually lack of complete ecosystem
structure.
§
Lake trout
was keeping lid, - > balance.
Whole ecosystem
seems to work better when we don’t knock out something.
Are the animals
merely exploiting resources or was selected by ecosystem for function as a
policeman?
Example : birds
flocking at trees with lots of insects – are birds policemen?
Why are natural
systems so stable without major disturbance? - They seem stable compared to
ones humans mock around.
Try reading this
article even two more times.
Estuaries - what
we need to know:
Ø very dynamic.
Ø Where rivers meet the sea.
§
Salt meadow
– a car is stuck. No waves = low energy environment. Broad monoculture.
§
Mouth of
north river, Massachusetts. Tidal.
§
Sweden,
Baltic. 35 ppt(thousand) or 3.5% salinity. Saltiness is extremely important.
Green water due to cultural eutrophication by sewage water from neighboring
countries. Rocky headlands(?): sea moves in toward the land. Erosion round the
edge exposing rocky core.
§
Mouth of a
small river in Nova Scotia. Boreal.
Last modified:
March 24, 2001
Any comments? E-mail
to akogwa@syr.edu