This national nature reserve is the most valuable Moravian locality with halophytic flora. Soluble salts necessary for occurrence of these vegetation species come from the bedrock sediments of the Tertiary sea and from mineral springs used in the past by the sulphuric spa in Sedlec. The rarest plants found in the territory include serpent root, halophytic aster, seaside ribwort, halophytic rush etc. Among other animal species found here there are six endangered butterfly species, such as moths, etc. The saline land is situated by the largest Moravian pond called Nesytu (315 ha), part of one of the oldest pond systems in Moravia, the Lednice Ponds. The ponds are internationally significant marshlands. At the same time they are valuable bird land of the Natura 2000 system. The ponds are nesting place for our rarest red-headed red-nib duck.