The early successional phase of dune slack development has damp bare sand visible and can be very species-rich, both in bryophytes and higher plant species, with variegated horsetail (Equisetum variegatum), articulated rush (Juncus articulatus), few-flowered spike-rush (Eleocharis quinqueflora) typically present. This young habitat is also important for hosting internationally rare species such as the fen orchid (Liparis loeselii) and petalwort (Petalophyllum ralfsii). However, both the pioneer seral phase of dune slack development and the species associated with it are declining rapidly as a result of succession to closed, mature slack vegetation.