Network biogeographical analysis of the central Aegean archipelago
Although the factors shaping plant species richness patterns across the islands of the central Aegean are well known, the processes driving the assembly of these island communities remain unclear. To shed light on these processes, we identified biogeographical modules within the phytogeographical area of the Cyclades and tested for nestedness across the islands.
The Cyclades, Greece.
We used a network approach to detect island biogeographical roles and modules, based on a large and detailed database of the Greek endemic plant taxa of the Cyclades, and we tested for nestedness in the island–species matrices.
The Cyclades were significantly modular and divided into five biogeographical modules. Three of the modules were significantly nested and two displayed all four possible biogeographical roles (connectors, module hubs, network hubs, peripherals). Most of the network's taxa are classified as peripherals and widespread endemics.
The borders of the five modules correspond remarkably well to the palaeogeographical and climatic compartmentalization of the Cyclades. The flora of the Cyclades has not yet reached the relaxation phase and the region may act as an ecogeographical filter for the distribution of several plant lineages. Naxos, Milos and Anafi play an important role for the network's connectivity, while at least five adjacent phytogeographical regions affect the distribution patterns of the endemic taxa present in the Cyclades.