ECOLOGICAL PRINCIPLES
CHAPTER 19
What is Ecology?
The study of interactions between organisms and the living and non-living components of
their environment.
Root: oikos (household), same as economics
“economy of nature”
BIOSPHERE“thin film of life covering an otherwise lifeless
planet”
http://www.planet-earth.org/images/bluemarble.jpg
ECOSYSTEM
Includes all of the organisms (biotic) and the non-living factors (abiotic) of an environment
found in a particular place
Biotic factors
All living things that affect the organism:
Shelter (Cover from plants)
Competition
Predation
Parasites
Available food supply (plants and animals)
Symbiotic relationships (“partnerships”)
Abiotic factors
All non-living things that affect the organism:Oxygen concentration
PrecipitationHumidity
TemperaturepH
Amount of sunlightAvailable nitrogen
Pollutants
COMMUNITYAll of the interacting organisms living in an area
(biotic factors)
danny.oz.au/travel/ new-zealand/p/1266-estuary.jpg
POPULATIONAll of the members of a species that live in one
place at one time
http://www.bionet.nsc.ru/booklet/images/imagesLaboratories/Kushnir3Big.jpg
http://www.buddycom.com/animal/special/elephant/elephwater.jpg
ORGANISMSimplest level of organization that focuses on
individual adaptations (variations in a group that make the individual
MORE FIT!)
http://131.183.60.23/brenda/brazil/organisms.jpg
BIOSPHERE
ECOSYSTEM
COMMUNITY
ORGANISM
POPULATION
Interconnectedness and Disturbance
http://ww
w.epa.gov/glnpo/atlas/im
ages/big05.gif
Ecological Niche (NICH)
Where it lives?
When is it active?
What it eats?
www.vancouver.wsu.edu/.../ holbrook06-2003.html
Niche
• The range of environmental conditions in which an organism can survive.
• There are two kind:– Fundamental Niche– Realized Niche
Niche Types
• Fundamental Niche:• What the organisms
is able to do• What it could eat• Where it could live• When it could be
active
• Realized Niche:• What the organism
actually does• Due to competition• Due to preference• Due to a lack of
options• Usually “Most highly
adapted to”
The Competitive Exclusion Principle
• What do you think this term means?
• No two organisms can occupy the same niche
• One organism will “out-compete” the other
• Those organism which are more poorly suited will either die or have to find a new niche where they can survive
Niche Differences
Generalists
• Broad niches• Tolerate a wide range
of conditions• Able to adjust easily
to disturbances• Jack-of-all-trades
Specialists
• Narrow niches• Very specific needs• Vulnerable to
disturbances• Really good at what
they do