What Shapes an Ecosystem? Today you will learn: 1. How biotic and abiotic factors influence an ecosystem. 2. How communities interact with each other. 3. What is ecological succession. What Shapes an Ecosystem?

I. What shapes an ecosystem? A. Ecosystems are influenced by a combination of biological and physical factors: Biotic and Abiotic factors.

Biotic Factors Biological influences on organisms within an ecosystem are the biotic factors. a. All living things in the community.

Abiotic Factors The physical or non-living factors that shape the ecosystem are the abiotic factors. a. The climate, weather, soil type, etc.

Working together B. Together the biotic and abiotic factors determine the success of the ecosystem.

Habitat The area in which an organism lives is called its habitat. 1. This includes biotic and abiotic factors.

Niche A niche refers to an organisms role in the ecosystem. 1. Worms: Decompose waste matter, provide food for birds, aerate the soil, but come to the surface after a heavy rain.

II. Interactions between organisms Interactions between organisms powerfully affect an ecosystem.

Competition Competition occurs when two organisms attempt to use a resource at the same time. a. Water, nutrients, sunlight, food, or space.

Competitive Exclusion Principle b. The Competitive Exclusion Principle states that no two species can occupy the same niche in the same habitat at the same time.

Predation Predation occurs when one organisms captures and eats another organism. a. Predator-Prey

Symbiosis Symbiosis is when two species live together. a. Three types of symbiotic relationships: Mutualism, Commensalism, and Parasitism

Mutualism b. Mutualism is when both species benefit from the relationship. (bees & flowers)

Commensalism In commensalism one member benefits, but the other isn’t harmed.

Parasitism d. In parasitism one organism lives on or inside an organism and harms it. a. Parasite-host

III. Ecological Succession A. Ecosystems are constantly changing and as old inhabitants die out, new inhabitants move in.

Succession Succession may be caused by deforestation, volcanic eruption, or a wildfire. It takes around 20-50 years for an ecosystem to return to its original state.

Pioneer Species B. Pioneer Species are the first species to populate an area.