Ecology – the study of the distribution and abundance of

68 Pages·2010·16.62 MB·English

by  American Chemical Society

Ecology – the study of the distribution and
abundance of organisms:
Who is where, when and why!
Different spins on ecology:
Organismal (& physiological)
Population
Community
Ecosystem/global
Organismal ecology
How do
individuals
interact with
each other and
their physical
environment?
The “interact…
physical
environment”
hook is the
physiological
ecology part.
Con-specific behaviors, like
aggression & territoriality affect
where you find organism s!
Population biology
How and why does
population size
change over time?
Each female
salmon produces
thousands of eggs.
Only a few will
survive to
The science of population growth
adulthood. On
is based on intrinsic biological
average, only two
factors, resource availability,
will return to the
immigration and emigration, and
stream of their

mortality.
birth to breed.
Community ecology
How do species
interact, and what are
the consequences?
In this case the bear is interacting with the fish by eating it.

The consequence for this fish is…the big stream in the sky!
Ecosystem ecology
How do energy and
nutrients cycle through
the environment?
(What happens to the
dead fish?)
Many communities, plus
abiotic factors, control
energy flow through the
biosphere.

Figure 50-1d Biological Science 2/e ©2005 Pearson Prentice Hall, Inc.
Abiotic factors (but not just) control where you find
organisms, and what types of organisms (physical and
physiological features).
For example, ambient temperature!
The basic needs of organisms:
1. Water
In general, life
2. Nutrients
is an interface
3. Energy
phenomenon!
Energy enters biosphere by organisms that trap it:
Photoautotrophs (green plants) or chemoautotrophs.
Energy available to photoautotrophs is not
evenly distributed, either geographically or
seasonally.
North pole
Small amount of sunlight per
unit area
60°N
Low angle of
incoming sunlight
Moderate angle of
incoming sunlight
30°N
Sunlight directly overhead
Large amount of
sunlight per unit
area
Equator
Uneven distribution of sunlight  uneven heating
BTW, life exists at the low end of the temperature scale
Sunlight – limits photosynthesis
Temperature depends on sunlight – speed of
chemical reactions in ectothermic organisms
Wind depends on temperature
So… differential sunlight  differential heating 
differential air movement
Of the three essentials:
Water
Sunlight is the most limiting
Nutrients
in the aquatic environment
Energy
and water in the terrestrial
environment.
Differential sunlight
Differential heating
Air movement
Air takes water along
… so differential sunlight controls water
distribution in the terrestrial environment.