Schwingmoor is a German word that translates into "swinging moorland". It is often used by those studying wetlands to refer to floating peat bogs formed by a layer of vegetation spreading across the surface of a body of water.
In most bogs the water underneath would fill up with sediment, and this may eventually happen with a Schwingmoor. But in the meantime, the layer of organic matter often becomes thick enough to walk on (carefully!), and gives an interesting bobbing and swaying effect to the ground.
Trees may grow on the Schwingmoor, and will sway when someone walks near them. When they become big enough, they break through the surface and fall to a watery death, leaving a temporary open pool.
Some people use Schwingmoor to specifically refer to a formation largely composed of the bog-moss Sphagnum, although I don't believe that there is any firm convention on this. As Sphagnum is the typical moss that grows in bogs, it may simply be a matter of fact that any Schwingmoor is bound to be largely composed it.
A Schwingmoor is a type of quaking bog.
'Schwingmoor' is always capitalized. Unlike many words borrowed from foreign languages, it is not usually written in italics.