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