Cross-scale influences of habitat and urbanisation on terrestrial vertebrates in coastal wetlands

Abstract Context Biodiversity in wetlands is impacted by expanding and intensifying urbanisation. While aquatic species spatial use of mangroves and saltmarshes is well established, little is known about how terrestrial vertebrates use these habitats in Australia and under what contexts. Objectives We surveyed terrestrial vertebrates in mangroves and saltmarshes in a diversity of estuarine seascapes, scaling from areas with extensive nearby urbanisation to more natural areas, and quantified the relative influence of habitat structure and composition, and landscape configuration on assemblage structure. Methods We surveyed terrestrial vertebrates using baited camera traps deployed for 48 h (i.e., four tidal cycles) across seven estuaries and 115 sites (57 mangrove and 58 saltmarsh) in southeast Queensland, Australia. We also quantified site-level habitat structure and landscape configuration metrics. Results We recorded 45 species within mangroves and 38 species within saltmarsh sites. Native species peaked at intermediate saltmarsh proximity and remnant land extent in mangroves, while saltmarsh native species increased with mangrove and remnant land area, and peaked with intermediate agriculture extents. Introduced species in mangroves increased with proximity to urban land, decreased with protected land extent, and peaked at intermediate saltmarsh and agriculture area, while saltmarsh introduced species increased with urban extent but decreased with remnant, protected land and mangrove extent. Minor habitat structure effects occurred in both habitats but were mediated by broader landscape effects or general structural components. Conclusions Landscape configuration, particularly connectivity to natural habitats versus urban matrices, fundamentally structures terrestrial vertebrate assemblages in mangrove–saltmarsh seascapes, overriding local habitat effects.