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Table of Contents
Unit 2 (you are here)
TOPIC 2.1 - Introduction to Biodiversity
ERT-2.A: Explain levels of biodiversity and their importance to ecosystems
- ERT-2.A.1: Biodiversity in an ecosystem includes genetic, species and habitat diversity.
- ERT-2.A.2: 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.
- ERT-2.A.3: Ecosystems that have a larger number of species are more likely to recover from disruptions.
- ERT-2.A.4: Loss of habitat leads to a loss of specialist species, followed by a loss of generalist species. It also leads to reduced number of species that have large territorial requirements.
- ERT-2.A.5: Species richness refers to the number of different species found in an ecosystem.
TOPIC 2.2 - Ecosystem Services
ERT-2.B: Describe ecosystem services.
- ERT-2.B.1: There are four categories of ecosystem services: provisioning, regulating, cultural, and supporting.
ERT-2.C: Describe the results of human disruptions to ecosystem services.
- ERT-2.C.1: Anthropogenic activities can disrupt ecosystem services, potentially resulting in economic and ecological consequences.
TOPIC 2.3 - Island Biogeography
ERT-2.D: Describe island biogeography.
- ERT-2.D.1: Island biogeography is the study of the ecological relationships and distribution of organisms on islands, and of these organisms’ community structures.
- ERT-2.D.2: Islands have been colonized in the past by new species arriving from elsewhere.
ERT-2.E: Describe the role of island biogeography in evolution.
- ERT-2.E.1: Many island species have evolved to be specialists versus generalists because of the limited resources, such as food and territory, on most islands. The long-term survival of specialists may be jeopardized if and when invasive species, typically generalists, are introduced and outcompete the specialists.
TOPIC 2.4 - Ecological Tolerance
ERT-2.F: Describe ecological tolerance.
- ERT-2.F.1: Ecological tolerance refers to the range of conditions, such as temperature, salinity, flow rate, and sunlight that an organism can endure before injury or death results.
- ERT-2.F.1: Ecological tolerance can apply to individuals and to species.
TOPIC 2.5 - Natural Disruptions to Ecosystems
ERT-2.G: Explain how natural disruptions, both short-term and long-term, impact an ecosystem
- ERT-2.G.1: Natural disruptions to ecosystems have environmental consequences that may, for a given occurrence, be as great as, or greater than, many human-made disruptions.
- ERT-2.G.2: Earth system processes operate on a range of scales in terms of time. Processes can be periodic, episodic, or random.
- ERT-2.G.3: Earth’s climate has changed over geological time for many reasons.
- ERT-2.G.4: Sea level has varied significantly as a result of changes in the amount of glacial ice on Earth over geological time.
- ERT-2.G.5: Major environmental change or upheaval commonly results in large swathes of habitat changes.
- ERT-2.G.6: Wildlife engages in both short-term and long-term migration for a variety of reasons, including natural disruptions.
TOPIC 2.6 - Adaptations
ERT-2.H: Describe how organisms adapt to their environment.
- ERT-2.H.1: Organisms adapt to their environment over time, both in short-term and long-term scales, via incremental changes at the genetic level.
- ERT-2.H.2: Environmental changes, either sudden or gradual, may threaten a species’ survival, requiring individuals to alter behaviors, move, or perish.
TOPIC 2.7 - Ecological Succession
ERT-2.I: Describe ecological succession.
- ERT-2.I.1: There are two main types of ecological succession: primary and secondary succession.
- ERT-2.I.2: A keystone species in an ecosystem is a species whose activities have a particularly significant role in determining community structure.
- ERT-2.I.3: An indicator species is a plant or animal that, by its presence, abundance, scarcity, or chemical composition, demonstrates that some distinctive aspect of the character or quality of an ecosystem that is present.
ERT-2.J: Describe the effects of ecological succession on ecosystems.
- ERT-2.J.1: Pioneer members of an early successional species commonly move into unoccupied habitat and over time adapt to its particular conditions, which may result in the origin of new species.
- ERT-2.J.2: Succession in a disturbed ecosystem will affect the total biomass, especially richness, and net productivity over time.