Fiveable Unit 2: Biodiversity
2.1: Intro to Biodiversity
*biodiversity is key to sustaining life in the constantly changing world
3 Different Forms
- Genetic
- Species
- Habitat
↳ each form plays a role in the survival of a population (with change organisms must be able to withstand these changes)
↳ a diverse gene pool (or species diversity) will allow for greater survival of individuals
Richness: how many different species inhabit the ecosystem (decline with distance from equator)
↳ measured with Simpson’s Diversity Index
Evenness: measures how the population sizes of each species in the ecosystem compares
2.2: Ecosystem Services
| SupportingThese services are necessary for other services to function | ProvisioningServices that can be traded in markets or used in households |
|---|---|
| RegulatingServices that you can’t see in actionEx. air quality, water flow, etc… | CulturalServices used for tourism, recreation, or aesthetic beauty |
2.3: Island Biogeography
↳ the size and distance from the mainland effect the number of species that a island can support
↳ immigration and extinction rates also play a part in the number of species on the island
Endemic Species: sensitive to change and are often wiped out by invasive species
Specialists: narrow niche
Invasive Species: species with few to no native predators
Generalists: broad niche
2.4: Ecological Tolerance
↳ conditional in habitats that are optimal for certain populations
↳ all populations need certain factors in order to survive
2.5: Natural Disruptions to Ecosystems
↳ the planet is constantly changing which has short term and long term effects on ecosystems
↳ randomly, periodically, or episodically
Resistance: measurement of how much an ecosystem changes after a disruption
Resilience: measure of how quickly the ecosystem can “bounce back” from the disturbance (recovery time)
↳ maximum species diversity is reached when an ecosystem experience an intermediate level of disturbance
2.6: Adaptations
↳ in order for a population to live in an ecosystem, they need the right traits in order to survive
Survival of the Fittest: species that have the right genes for the ecosystem tend to live longer
Evolution: as ecosystems change species must change as well (inevitable)
Reproductive Isolation: two populations are no longer able to reproduce with each other
Allopathic Speciation: physical barrier
Sympatric Speciation: same area but do not reproduce (different times/seasons)
2.7: Ecological Succession
↳ gradual change an ecosystem experiences over time until it reaches stability
Climax Community: stable ecosystem
Primary Succession: when there is only rock in the area (volcanoes or glaciers)
Secondary Succession: the soil is present (less time)
Keystone Species: species depended upon by other species in the ecosystem such that if it were removed the ecosystem would change dramatically
Indicator Species: species that reflects the health of its ecosystem