1. ECOSYSTEMS

2. Key Concepts How do biotic & abiotic factors influence an ecosystem?
What interactions occur within communities?
What is ecological succession?

3. Abiotic vs. biotic
The biological influences on organisms within an ecosystem are called biotic factors.
Plants, bacteria, animals (living factors)
Physical or non-living factors that shape ecosystems are abiotic factors.
Precipitation, humidity, sunlight, etc.
Together, biotic and abiotic fact determine the survival & growth of an organism.

4. Abiotic vs. biotic (cont.)
An area where an organism lives is called a habitat.
A habitat includes both abiotic and biotic factors.

6. Niche
A niche is the full range of physical and biological conditions in which an organism lives.
Includes the type of food, how its obtained, and what species eat the food.
Also includes how and when it reproduces.
No two species can share the same niche in the same habitat.
Habitat vs. niche

7. Community Interactions
Competition, predation, and various forms of symbiosis affect an ecosystem.
Predation – an interaction in which an organism captures and feeds on another organism.
Predator and prey

9. Community Interactions
Symbiosis – A relationship in which two species live closely together
“living together”
3 main classes of a symbiotic relationship
Mutualism
Commensalism
Parasitism

10. Symbiosis relationships
Mutualism – both species benefit
Insects and flowers
Commensalism – one organism is benefited the other is neither harmed nor helped.
Barnacles on whales
Parasitism – one organism lives and harms another organism.
Tapeworms inside mammals

11. Symbiosis relationships

12. Ecological Successions
The series of predictable changes that occurs in a community over time is called ecological succession.
Successions that occur on surfaces where no soil exists is called primary succession.
Volcanic eruptions, glaciers, etc.
Pioneer species are first to populate an area
Succession following a disturbance that destroys a community
After wildfires, floods, etc.

14. Organization in ecosystems
Species: a group of organisms so similar they can breed
Population: groups of individuals belonging to the same species
Communities: assemblies of different populations that live together
Ecosystem: collection of all organisms in a particular place.
Biome: group of ecosystems that have the same climate.