threats to biodiversity

• HIPPO

  habitat destruction

  invasive species

  population

  pollution

  overharvesting
• population bottleneck

  sharp reduction in the size of a population for at least one generation. this reduces the genetic diversity of a population due to a chance of alleles being lost
• consequences of a population bottleneck

  • genetic diversity is lost and does not recover
  • small populations may lose the genetic variation necessary to enable evolutionary responses to environmental change
  • inbreeding occurs which can result in poor reproductive rates
• naturalised species

  species that become established within wild communities
• invasive species

  naturalised species that spread rapidly and eliminate native species, therefor reducing species diversity
• habitat fragmentation

  when a habitat is divided into several smaller habitat by roads, agriculture or urbanisation

  decreases species richness
• consequences of habitat fragmentation

  suffer from degradation at edges, reduces size

  increased competition between species

  lower species diversity

  decrease in biodiversity