Island biogeography

Definition

Island biogeography is the study of the distribution and diversity of species on islands and the factors that influence these patterns. It examines how the size, isolation, and habitat diversity of islands affect species richness and extinction rates, providing insights into ecological processes and species interactions. This field also emphasizes how these principles apply to habitat fragmentation in larger landscapes, influencing biodiversity and ecological succession.

5 Must Know Facts For Your Next Test

1. Larger islands tend to support more species due to greater habitat variety and lower extinction rates compared to smaller islands.
2. Isolated islands often have unique species not found elsewhere due to evolutionary processes such as adaptive radiation.
3. The distance from a mainland source influences colonization rates; closer islands generally have higher immigration rates.
4. Ecological succession on islands can lead to changes in species composition over time as new species colonize and others become extinct.
5. Island biogeography principles apply not only to oceanic islands but also to isolated habitats like mountain ranges and forest fragments.

Review Questions

• How do size and isolation of an island impact its species diversity according to island biogeography?
  • According to island biogeography, larger islands can support more species because they offer a greater variety of habitats and resources, which reduces extinction rates. On the other hand, isolated islands are less accessible for potential colonizers, leading to lower immigration rates. The balance between these factors determines the overall biodiversity found on different islands.
• Discuss the implications of island biogeography principles for conservation efforts in fragmented landscapes.
  • The principles of island biogeography highlight the importance of maintaining large, connected habitats to support diverse species populations. In fragmented landscapes, preserving corridors between habitat patches can enhance connectivity, allowing for better movement of species and increased genetic diversity. Understanding how size and isolation affect biodiversity can guide conservation strategies aimed at minimizing extinction risks in these altered environments.
• Evaluate the role of ecological succession in shaping the biodiversity of island ecosystems over time.
  • Ecological succession plays a crucial role in shaping island biodiversity by determining how communities change following disturbances or colonization events. As new species arrive, they interact with existing ones, leading to shifts in community structure and potentially creating new niches. Over time, these interactions can result in a more stable ecosystem with increased complexity, influencing overall species richness and providing insights into how resilience can be fostered in changing environments.

Related terms

Equilibrium Theory: A theory that predicts the number of species on an island based on immigration rates and extinction rates, balancing the two to reach a state of equilibrium.

Habitat Fragmentation: The process where large, continuous habitats are divided into smaller, isolated patches, affecting species distribution and biodiversity.

Biogeographic Regions: Areas defined by distinct plant and animal distributions, which can be influenced by historical factors, geographic barriers, and ecological conditions.