Ecosystems

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Biotic and Abiotic Factors

• All Earthly organisms are found in the Biosphere.

  • Includes:

    • Land

    • Water

    • Lowest part of the atmosphere

Living things can be found almost everywhere including very hot and cold places as well as the deep ocean.

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Biotic and Abiotic Factors

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• Ecosystem

  • Includes all living and non-living parts of the environment as well as the interactions among them.

• Biotic Factors

  • Living parts of an ecosystem

  • Includes remains and wastes

• Abiotic Factors

  • Non-living parts of an ecosystem

  • Includes light, temperature, weather, soil and water

Biotic and Abiotic Factors

• ​Niche - How an organism acts within its ecosystem

• • Some animals eat other animals, some eat plants

  • Some plants grow in sunny areas, some need shade

  • Worms and bacteria break down dead organisms for energy and recycle the nutrients into the ecosystem

  • This creates Biodiversity

  The variety of life in the world or in a particular habitat or ecosystem.

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Levels of Organization

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• An organism is any living thing

• Species

  • A group of organisms that share most characteristics and can breed with one another.

• Population

  • All organisms of a species that live in the same place at the same time

  • Members of a population compete with each other for resources for survival

• Community

  • All of the populations that live in an area at the same time

• Ecosystem

  • One or more communities and their nonliving environment

Relationships in Ecosystems

• An ecosystem includes all the living and non-living things that interact with each other in a certain environment.

• Organisms interact with each other as well as with other organisms of their own species

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What is a Limiting Factor?

• Limiting Factors are…

    (two similar definitions) 

• conditions of the environment that limit the growth of a species.

• biotic and abiotic factors that prevent the continuous growth of a population.

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​Carrying Capacity

• Because of these limiting factors, each ecosystem has a finite capacity for growth connected to its carrying capacity.

• ​Carrying capacity is the number of individuals of a species that an ecosystem can support

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Density Dependent vs. Density Independent Factors

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​Population density describes the number of individuals in a given area.​

Density-dependent factors will affect a population differently based on its population density. (For example, a disease affects a high population!)

​Density-independent factors can affect all populations, regardless of their density.