Biotic - ALL living organisms
Abiotic - non-living components (soil, rocks, sunlight, wind, rain)
Habitat - The place where a population lives

Niche - The physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.
No two species can share the same niche in the same habitat. ( See Fig. 4-5 )

Community Interactions

Competition -compete for resources | Competitive Exclusion Principle - no two species can occupy the same niche
Predation - one organism captures and feeds on another organism (prey)

Symbiosis - two species live closely together

a. Mutualism - both species benefit (insects pollinate flowers)
b. Commensalism - one member is benefits and the other is neither helped or harmed
c. Parasitism - one organism lives in or on another and harms it (blood sucking tick)

Ecological Succession - predictable changes that occurs in a community over time

Primary Succession - occurs on land where no soil exists (ex; volcanic eruptions) see figure 4-7

Pioneer species - the first species to populate this area

Secondary Succession - occurs in areas where there has been previous growth (ex: fires, abandoned fields)
*Climax Community*

Marine Succession - "whale-fall" 3 distinct stages see Figure 4-9