beach scences dune flora encroaching sand old fence posts sand sand dunes coast coastline colors colours conservation conserve conserving cultivating cultivation dune-flora dunes environment environmental flora grass grasses green greenery growing growth natural nature ocean ocean edge planting plants protect protection reclaim reclamation replanting rough salt-resistant sand-dunes scrub vegetation beach levels low tide ocean waterline receded receding receding tide Sandbar tidal tides water waterline backdrop background coastal contrast contrasting foliage leafy leaves light ocean-edge ocean-waterline