4-2 What shapes an ecosystem? IaN pg. 61 MAIN IDEAS 1.Biotic Factor 2.Abiotic Factor 3.Niche 4.Competitive Exclusion Principle 5.Ecological Succession Objective Identify the interactions within communities explaining how disturbances, biotic & abiotic factors effect an ecosystem. Key Concepts: 1. How do abiotic & biotic factors influence an ecosystem? 2. What interactions occur within communities? 3. What is ecological succession?

I. Biotic & Abiotic Factors A.Living = Biotic B.Non-living = Abiotic Create a 5 line “T” Chart in your notes. Label 1 column Biotic the other Abiotic. List at least 5 Biotic factors found in the grassland ecosystem of Prescott Valley and 5 Abiotic Factors. Biotic FactorsAbiotic Factors

II. The Niche A.Occupation of an organism within a habitat. Including: 1.Type of food it eats, Trophic Level 2.Physical conditions needed to survive 3.Reproduction methods (When, Type)

III. Community Interactions Interaction Type Species 1 (+, - or 0) Species 2 (+, - or 0) Description w/ Example Competitive Predation Mutualism Commensalism Parasitism Use your textbook to complete the table below in your notes. A.Competitive Exclusion Rule = ? B. Symbiosis = ?

IV. Ecological Succession = Series of predictable changes to a community over time. A. Primary Succession = No soil exists. Bare rock. 1. Pioneer Species = 1 st Species to populate a Primary Succession area.

B. Secondary Succession = soil remains following disturbance 1. Wildfires, Clear cutting, Abandoned Farm land Explain what a Climax Community is? How is it defined? Is it permanent?

C. Marine Succession = soil remains following disturbance Describe the 3 examples of ecological succession in a marine system? (pgs )

IaN pg. 62 Glue down & complete the Graphic Organizer Handout.