APES unit 2

• Biodiversity

  The diversity of different life forms found in an ecosystem
• Levels of biodiversity

  • Genetic Biodiversity
  • Species Biodiversity
  • Ecosystem Biodiversity
• Genetic Biodiversity

  The variance of genes or traits found within individuals of a population
• Species Biodiversity

  The diversity of different types of organisms found in an ecosystem
• Ecosystem Biodiversity

  The variance in the different ecosystems found in a given area
• The three levels of biodiversity are nested within each other
• Genetic Biodiversity example

  • A population of sparrows with high genetic diversity will increase the likelihood that some of them have bigger beaks that can still crack open harder seeds during a drought.
• Species Richness

  A count of the total number of different species found in a given ecosystem
• Species Evenness

  The distribution or balance of the population sizes of all the different populations present
• Species Biodiversity example

  • Forest 1 has higher species evenness than Forest 2, so if a disease spreads, Forest 1 would have more species to repopulate.
• Ecosystem Biodiversity example

  • A tropical rainforest has high ecosystem biodiversity with diverse ecosystems, while a desert biome has low ecosystem biodiversity.
• Ecosystem Services

  • Provisioning Services
  • Supporting Services
  • Regulating Services
  • Cultural Services
• Ecosystem Services example

  • The Deepwater Horizon oil spill disrupted ecosystem services like fisheries, tourism, and mangrove swamps.
• Theory of Island Biogeography

  • The closer an island is to the mainland, the higher its species richness
  • The larger the island, the higher its species richness
• Ecological Tolerance

  The range of conditions an organism or species can tolerate before death or serious injury ensues
• Physiological Stress

  When an organism moves outside of its optimal range, it enters the zone of physiological stress
• Genetic Diversity

  Acts as a buffer against environmental disturbances, allowing some individuals to have a wider range of tolerance
• Types of Environmental Disturbances

  • Periodic Events
  • Episodic Events
  • Random Events
• Variations in Earth's Orbit

  • Eccentricity
  • Axial Precession
  • Obliquity
• Adaptation

  A genetic mutation that gives an organism a higher likelihood of surviving and reproducing in a changed environment
• Adaptation example

  • Opposable thumbs in early humans allowed for a tighter grip, tool use, and access to energy-rich marrow
• Primary Succession

  The process of pioneer species colonizing a bare rock ecosystem, followed by the growth of intermediate and climax communities
• Secondary Succession

  The process of pioneer species colonizing disturbed soil, followed by the growth of intermediate and climax communities
• Keystone Species

  A species that plays a vital role in its ecosystem, and whose removal can cause the entire ecosystem to collapse
• Keystone Species examples

  • Wolves, Beavers, Mangroves