Lesson 4 - human impact on biodiversity

• What do many scientists believe we are currently experiencing due to human impact?


  The 6th mass extinction
• When did the previous mass extinctions occur?


  65 million years ago during the Cretaceous period
• Why can't wildlife adapt to the changes caused by humans?


  Because the changes are happening too rapidly
• What are the main causes of loss of biodiversity?

  • Habitat Loss
  • Invasive Species
  • Hunting
  • Genetic Loss
• What is the primary reason for loss of species worldwide?

  Habitat Loss
• How does habitat loss affect species diversity?


  As ecosystems are lost, the number of species declines
• What does NPP stand for in the context of biodiversity?


  Net Primary Productivity
• What is the formula for NPP?


  $NPP =$$GPP - R$
• What is habitat fragmentation?


  It isolates populations, disrupting mating and reducing gene flow
• What principle explains competition between species in the same ecological niche?

  The Competitive Exclusion Principle
• What are generalists and specialists in ecology?


  Generalists have a broad niche; specialists have a narrow niche
• What is the second biggest reason for loss of species worldwide?

  Invasive Species
• What is the third biggest reason for the loss of species worldwide?

  Hunting
• What is a significant cultural reason for hunting sharks?

  Shark Fin Soup
• How much have shark populations declined globally over the past 50 years?


  70%
• Why are sharks considered a keystone species?


  They have a top-down trophic cascade effect on biodiversity
• What is the role of bees in our ecosystem?


  They pollinate plants, which is essential for 1/3 of our food
• What percentage of wildflower meadows have been lost since WWII?


  97%
• What are neonicotinoids?


  A group of insecticides harmful to bees
• What is the result of reduced genetic diversity in populations?


  Increased inbreeding and vulnerability to disturbances
• What is monocropping?


  Industrialized farming producing only one type of crop
• What is a genetic bottleneck?


  A significant reduction in population size leading to less genetic diversity
• How many bottlenecks have cheetahs experienced?

  Two
• What is the purpose of conservation of wild spaces?

  To protect ecosystems and species diversity
• What is remediation in the context of biodiversity?


  Actions taken to stop human impacts on ecosystems
• What is an example of mitigation to lessen human impacts?

  Fish ladders for salmon at dams
• What is restoration in biodiversity efforts?

  Restoring impacted areas back to their natural conditions
• What is the role of wildlife corridors?

  To facilitate migration and gene flow between populations
• What does the Endangered Species Act prohibit?


  The import, export, or taking of threatened or endangered species
• What does CITES stand for?

  Convention on International Trade of Endangered Species
• How did the Florida Panther recover from its bottleneck?

  By creating artificial gene flow through interbreeding with pumas from Texas
• What is Island Biogeography?


  • Study of ecological relationships and distribution of organisms on islands
  • Fragmentation creates artificial islands
  • Helps understand species richness in fragmented communities
• How do invasive species affect islands?


  They have a greater negative impact and are the leading cause of extinction on islands
• Why do island species tend to be specialists?


  Due to limited resources and smaller territories
• What is the impact of invasive species on biodiversity?


  They outcompete specialists and reduce biodiversity