APES 2.1 Introduction to Biodiversity

Enduring Understanding:

• Ecosystems have structure and diversity that change over time.

Learning Objective:

• Explain levels of biodiversity and their importance to ecosystems.

Essential Knowledge:

• Biodiversity in an ecosystem includes genetic, species, and habitat diversity.
• The more genetically diverse a population is, the better it can respond to environmental stressors.  Additionally, a population bottleneck can lead to a loss of genetic diversity.
• Ecosystems that have a larger number of species are more likely to recover from disruptions.
• Loss of habitat leads to a loss of specialist species, followed by a loss of generalist species.  It also leads to reduced numbers of species that have large territorial requirements.
• Species richness refers to the number of different species found in an ecosystem.

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\ Biodiversity can be addressed on a variety of levels

• Ecosystem diversity: The variety of ecosystems within a given area
• Species diversity: The variety of species within a given ecosystem
• Genetic diversity: The variety of genes within a given species

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• Ecosystem diversity as a term incorporates both habitat and community diversity
• The diversity of species, genes, and ecosystems play a significant role in the normal functioning of natural systems/cycle, including those that humans utilize everyday

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• Species richness: The number of species in a given area
• Species evenness: The relative proportion of different species in a given area

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