Larger Islands

Definition

Larger islands are land masses that have a greater surface area compared to smaller islands, which significantly influences the biodiversity and species richness they can support. These islands often have more varied habitats, leading to higher levels of ecological niches and, therefore, a greater number of species. The size of an island is a crucial factor in island biogeography, as it affects both immigration rates and extinction rates of species.

5 Must Know Facts For Your Next Test

1. Larger islands typically have higher species richness because they can provide a variety of habitats and resources for different organisms.
2. The size of an island impacts the balance between immigration and extinction rates; larger islands generally experience lower extinction rates due to larger populations and more diverse ecosystems.
3. Larger islands can also serve as 'source' islands for smaller nearby islands, facilitating the movement of species through dispersal.
4. Habitat diversity is often greater on larger islands, leading to the presence of more ecological niches that can be filled by various species.
5. Some larger islands may exhibit unique evolutionary pathways, leading to the development of endemic species that are not found anywhere else.

Review Questions

• How does the size of an island affect the biodiversity it can support?
  • The size of an island plays a significant role in determining its biodiversity because larger islands offer more varied habitats and ecological niches. This increased habitat diversity allows for a greater number of species to coexist, as different organisms can exploit different resources. Additionally, larger areas can sustain larger populations, which reduces the risk of extinction due to demographic fluctuations.
• Evaluate the implications of the Species-Area Relationship for conservation efforts focused on island ecosystems.
  • The Species-Area Relationship highlights that conservation efforts should prioritize preserving larger habitats to maintain or enhance biodiversity on islands. Since larger areas support more species, conserving large tracts of land can help mitigate extinction risks for vulnerable species. This relationship also emphasizes the need for connecting smaller habitats through wildlife corridors, ensuring that species can migrate and colonize new areas, ultimately maintaining genetic diversity and ecosystem health.
• Synthesize how the concepts of isolation and larger island size work together to shape the evolutionary outcomes of island species.
  • Isolation combined with larger island size creates a unique environment for evolutionary outcomes in island species. Larger islands provide a greater number of resources and habitats, allowing for diverse ecological niches where species can adapt and evolve. However, isolation limits gene flow between populations, leading to distinct evolutionary paths. Over time, this isolation on larger islands may result in the emergence of endemic species, which are uniquely adapted to their environments and play specific roles within their ecosystems.

Related terms

Species-Area Relationship: The principle stating that larger areas tend to support more species due to increased habitat diversity and available resources.

Isolation: The degree to which an island is separated from mainland or other islands, impacting species immigration and colonization.

Endemic Species:

Species that are native to and found only within a specific location, often thriving on larger islands due to their unique habitats.