Archipelago bird habitat suitability evaluation based on a model of form-structure-function-disturbance

Abstract

Archipelagos are always the key nodes of bird migration routes, but they exhibit ecological vulnerability and heterogeneity due to their unique natural conditions and various human disturbances. An evaluation of archipelago bird habitat suitability that focuses on archipelago features is essential for island ecosystem conservation under human disturbances and for optimisation of bird migration routes. A form-structure-function-disturbance (FSFD) model for archipelago bird habitat suitability was established, and the spatial distributions of habitat suitability were analysed at the island and grid scales on Miaodao Archipelago, which are important islands in North China. Results indicated that form values were high in islands with large areas and centre position; structure values were high in areas with simple terrain condition and landscape pattern; function values were lower in traffic, building and bare lands than those in plantation and grassland; and disturbance values were closely related to human activities, which were lower in inhabited islands than those in uninhabited islands, and in traffic and building lands than those in other areas. The archipelago bird habitat suitability showed evident spatial heterogeneity. At the island scale, five islands were in status of good suitability, and 27 islands were in status of ordinary suitability; the different suitability levels at the grid scale were ordinary suitability, good suitability, poor suitability and best suitability in the descending order of areas. FSFD were determined by natural and anthropogenic factors, and human disturbance was the major factor that influences the spatial distribution of archipelago bird habitat suitability.