ECOLOGY
“No man is an
island entire of
itself. Every man
is a piece of a
continent, a part
of the main”
-John Donne
What is Ecology?
• The study of the interactions of organisms with
one another and with their physical environment.
Physical Environment (non-living)
ex- water, air, dirt, rocks
Organisms that are living (or
WERE living at one time….
paper, steak) ex- animals,
plants, bacteria, fungus
Individual Community
Biome
Ecosystem
Population Biosphere
1
2
3
All
Category
A+B
B only
1 Species
1
4
5
6
Can we go smaller ?
*self-sustaining
Major Biological communities that occur over
wide areas on land are called Biomes.
Distribution
Climate
Life/Organisms
Human Impact
TUNDRA
Distribution
Climate
Life/Organisms
Human Impact
Deciduous
Forest
Distribution
Climate
Life/Organisms
Human Impact
Tropical Rain Forest
Distribution
Climate
Life/Organisms
Human Impact
Desert
Distribution
Climate
Life/Organisms
Human Impact
Important Terms
• Producer/Autotroph (Auto = self, troph = feeder)
– organisms that produce their own food directly from
the sun’s energy.
• Take in energy from their surroundings and and
store it in complex molecules such as
carbohydrates.
• Use the process of photosynthesis to make
complex molecules
• Consumers/Heterotrophs (hetero = other)
– Organisms that obtain energy by
consuming other organisms.
• Feed on producers & other
consumers
Can be:
• herbivores
• carnivores
• omnivores
• decomposers
Important Terms
• Primary Consumer – Feeds on plants. All are
herbivores.
• Secondary Consumer – Feeds on primary consumers.
May be omnivore or carnivore
• Tertiary Consumer – Feeds on secondary consumer.
May be omnivore or carnivore
• Quaternary Consumer – Feeds on tertiary consumer.
May be omnivore or carnivore.
Food Chain or
Food Web?
Trophic levels:
# OF Energy
Steps from the
Sun
Competition
Inter = Between
different species
Intra = within one
species
Battle at Kruger 8.24
Predation
Predator
Prey
Pursuit, ambush
Ch 53#3, extension 1- protection of young, CH51 Extension#1,5
Pair, Share, Explain
A population increase in which the population "overshoots" the carrying capacity, K,
and then crashes precipitously. Note that after the crash the population rebounds
somewhat and approaches a new stable size (dN/dt = 0). Note that the carrying
capacity has also changed. In the case of the Kaibab deer, this would represent
irreversible (or at least very long term) changes in the amount of food available.
Plant Defenses
• Adaptions to improve
• Survival & Reproduction:
Mechanical, Chemical
*Cuticle- keep water in, pathogens out; close the stomata! Spines! Thorns!
*Polymers to reduce digestibility; Odor!
*Essential oils- attract predatory insects to kill plant-feeding insects
Ch 53#6, extension 1
Camouflage
“Cryptic Coloration”
Malaysian orchid mantis
Grey Cicada
* Octopus
4.37Camouflage
* Grizzly Bear
http://www.dailymail.co.uk/sciencetech/article-1080207/Masters-disguise-Stunning-pictures-tricks-used-creaturescamouflage-themselves.html
The yellow banded poison
dart frog
Aposematic “warning” Coloration
Mimicry
* The harmless mimic gains the same advantage as the dangerous model.
* The ‘duped’ predator brings about this evolutionary change. How?
* While the increased # could benefit both species, the model could be
disadvantaged in this process. How?
• The ‘model’ is still an
aposematic prey.
• The Viceroy butterfly
‘mimic’(top) appears very
similar to the noxious tasting
Monarch butterfly (bottom).
• However, the viceroy is actually
more unpalatable than the
monarch
• The model benefits from being
mimic- increasing numbers of
toxic prey out there warning
away predators
• The predator is not ‘duped’both really are harmful
Mimicry
• No two species can coexist in a community if
they share a niche
(have the same needs).
• Where there is overlap,
competition goes on
and one species will
always win out.
Competitive
Exclusion
Principle
p400 text
Resource Partitioning
• Instead of out
competing
another
species- they
co-exist
• Other ways?
• location
• time of day
• nesting sites
or times
• Food type
• plant root
depth
Symbiosis
Symbiosis
Mutualism
Commensalism
Parasitism
+/+
+/0
+/-(host)
An intimate relationship between two
or more organisms of different species.
P/S: examples of each?
?
Mutualism
Ectoparasite
?
Parasitism
Ecto or endo?
Endoparasite
?
Parasitism…..
ecto or endo?
Lichen:
Fungus + Algae
?
Mutualism
?
Mutualism
The “crocodile bird- Egyptian plover…subsaharan Africa
?
Commensalism
Keystone vs Dominant Species
•
•
•
•
Definitions: ?
P/S: Humans: keystone or dominant species?
Dominant: Most abundant species in a community
Keystone: Species that has greater influence on
community structure than you would predict based on
#’s. Maintains species diversity (predation)
• Grey Wolf
• Fig Tree
• ?
Energy flow through ecosystems
10% Rule
NPP = GPP - CR
CH54#2
Most ecological pyramids are large at the
base and narrow at the top.
This is because every time
that an organism is eaten
by the next trophic level,
some of the energy is lost
as heat.
Less Energy
More Energy
Pyramid of Energy:
• Shows the energy available at each trophic level.
– The size of the blocks represents the
proportion of energy
– Measured in Joules or Calories
Pyramid of Numbers:
• Illustration of the number of organisms at
each level