ORIGINAL ARTICLE: Not as the crow flies: assessing effective isolation for island biogeographical analysis

摘要: Aim  To evaluate the role of island isolation in explaining distribution vascular plant species a dense freshwater archipelago, specifically comparing conventional measures with landscape isolation. Location  Data were collected from 35 islands within Massasauga Provincial Park on eastern shores Georgian Bay, Ontario, Canada. Methods  Sampled located using stratified random selection based location and size variation. The number was recorded along transects. Island variables included distance to mainland, nearest island, largest gap stepping-stone sequence, closest upwind point land, measure isolation. quantified as percentage land area 100, 250, 500, 1000, 1500 2000 m each island’s perimeter. calculated geographical information system (GIS). Dependent regression analyses richness, logarithm richness residuals species–area relationship. Independent their logarithmic transformations. Results  Isolation plays role, albeit small, study area. In analyses, provided better fit than Islands less water 250-m buffer more effectively isolated had fewer present surrounded by greater proportion water. Main conclusions  Consistent species–isolation relationship, area, elucidated series buffers GIS. Applying similar dense, archipelagos may elucidate patterns not evident through conventional, straight-line measurements low value coefficients well history high density suggests caution extending results, especially dissimilar archipelagos.