The lunar nodal cycle controls mangrove canopy cover on the Australian continent.

Long-phase (interannual) tidal cycles have been shown to influence coastal flooding and sedimentation, but their role in shaping the extent and condition of tidal wetlands has received little attention. Here, we show that the 18.61-year lunar nodal cycle, popularly termed the "lunar wobble," is a dominant control over the expansion and contraction of mangrove canopy cover over much of the Australian continent.