Section 4-2 Notes
{
Niche, Community Interactions (symbiosis)
{ Biotic factors
Biological influences
within an ecosystem.
{ Abiotic factors
Physical/nonliving
factors that shape
ecosystems
Biotic and Abiotic factors?
Abiotic or biotic factor?
Niche
Definition – full range of physical and
biological conditions in which an organism
lives and the way in which the organism uses
those conditions
Food specifically –
1. type of food organism eats
2. how it obtains this food
3. which other species use the organism
as food.
Niche continued
Can different species share the same niche in
the same habitat? Answer: No.
Different species can occupy niches that are
very similar? Answer: Yes.
Cape May Warbler
Bay-Breasted Warbler
Yellow-Rumped Warbler
Do all 3 species of warbler occupy the
same niche?
Community Interactions
Community interactions such as competition,
predation, and various forms of symbiosis can
powerfully affect an ecosystem.
Community Interactions – Competition
Competition occurs when organisms of the
same or different species attempt to use an
ecological resource in the same place at the
same time.
Resource refers to any necessity of life, such
as water, nutrients, light, food, or space.
Community Interactions – Predation
Predation – An interaction in which one
organism captures and feeds on another
organism.
Predator?
Prey?
Community Interactions – Symbiosis
Symbiosis – any relationship in which two
species live closely together
Main classes of symbiotic relationships
1. mutualism
2. commensalism
3. parasitism
Mutualism
Both species benefit from the relationship.
Commensalism
One member of the association benefits and
the other is neither helped nor harmed.
Parasitism
One organism lives on or inside another
organism and harms it.