crossarchipelago

Crossarchipelago is a term used in ecology and biogeography to describe processes that connect populations across different archipelagos, including dispersal, gene flow, colonization, and community assembly across islands separated by water.

The concept applies to both marine and terrestrial organisms and emphasizes patterns of connectivity over ecological time scales, influencing genetic diversity, population structure, and the potential for speciation across archipelago systems.

Key mechanisms include natural dispersal by flight, drifting in currents or on rafts, larval dispersal in marine species, and occasionally human-mediated transport. Islands can act as stepping-stones, creating a network of connectivity that spans multiple archipelagos.

Researchers study crossarchipelago dynamics with phylogeography and population genomics to infer historical and contemporary gene flow, and with models that incorporate ocean currents, wind patterns, and species dispersal traits.

Crossarchipelago analyses have been used to understand biodiversity patterns in archipelagic regions such as Southeast Asia, the Caribbean, the North Atlantic and the Pacific, and to inform conservation planning by identifying networks of habitat and corridors across islands.

The term emerged from general island biogeography and metapopulation theory and has grown as genomic data allow finer resolution of inter-archipelago connectivity; it is sometimes called cross-archipelago connectivity or inter-archipelago dispersal.

See also: island biogeography, metapopulation, phylogeography, dispersal ecology, conservation biology.