Island Biogeography Theory: Emerging Patterns and Human Effects
Islands are conventionally (and narrowly) referred to as isolated lands in surrounding waters. However, in broad senses and when loosely defined, ‘islands’ also include insular areas or entities such as mountain tops, lakes (e.g., potholes in northern Great Plains in North America), oasis (in deserts), and springs (especially in deserts) that support unique species assemblages relative to surrounding habitats (e.g., Brown, 1978; Lomolino et al., 2006). Mostly because of the insular nature, habitats on oceanic islands are often different from those on the nearest mainland even when latitudes (climates) and the sizes (areas) are the same. For example, islands often support unique species assemblages with proportionally more rare and endemic species with small population sizes (e.g., reduced body size or the so-called insular dwarfism and dispersal). Partly because of their unique features (e.g., isolation) and conservation values, islands are extremely attractive for intensive efforts in exploration, research, and conservation (e.g., Kalmar and Currie, 2006).