Management Recommendations Based on Physical Forces Driving Land-Covers and Habitat Preferences of Polychaete and Bird Assemblages for a Mangrove-Vegetated Estuary

Mangrove overexpansion monopolizes estuarine landscapes by diminishing land-cover type diversity and hence biodiversity. Preferences of land-cover types by polychaete and bird assemblages as they relate to associated physical driving forces warrant investigation. In a mangrove-vegetated nature reserve, six land-cover types were found and aligned along elevation, inundation and sedimentary gradients. However, only three land-cover types were preferred by polychaetes, mainly tidal flats with intermediate and high inundation, and mangroves. Each land-cover type was differentiated by a distinctive species. The density of the nereid, the prey of shorebirds, was well explained by increasing flow velocity of the tidal flats. Five land-cover types were preferred by birds. Shorebirds recognized tidal flats for foraging where large, open surface areas shaped the places. Wintering egret also preferred feeding on open tidal flats and the residential egret favors nesting on tall and thick trunk mangroves. These egret-differentiated land-covers were regulated by lengthening inundation. Foliage and ground gleaners preferred dense, tall and thick trunk mangroves. The shorebird abundance could be enhanced 2.25 times if the open tidal surface area increased 1.5 times more than the current level. Our results identify useful, applicable physical driving parameters and suggest effective management strategies for conserving mangrove-vegetated wetlands. ? 2021, Society of Wetland Scientists.