Poor Fen

14th May 2012, Monday

Not a term of commiseration, or criticism, but the name for one of the scarcest habitats in the RX region.
Poor fen habitat
The poor fen communities in the Cladium Pit at Dungeness RSPB reserve are bursting into life at the moment following the cutting back of tall reeds last autumn.  Bottle sedge Carex rostrata is starting to flower and is more widespread than at any time since the clearing of shading willows allowed it to reappear from the seed-bank fourteen years ago.  Although it grew in scattered locations across Kent in 1899 this is the only location where this plant was found in Kent, despite targetted searches, during the surveys that resulted in the 2010 New Atlas of the Kent Flora by Eric Philp.  It has declined generally over southern England due to habitat loss.

Flowering bottle sedge

Another plant that is abundant in this fen is marsh fern Thelypteris palustris.  

Marsh fern

This nationally scarce plant is found in most of the natural pits at Dungeness, and unlike bottle sedge can thrive under shading willows, but it was good to see it thriving in the absence of trees.

These plants were growing on a ridge of acidic peat in the centre of the pit, created by the accumulation of plant remains over hundreds of years, including Sphagnum  squarrosum.

Sphagnum squarrosum

In the lower-lying areas around the outside of the pit fen plants typical of more neutral conditions can be found, with yellow flag iris Iris pseudacorus starting to flower, a valuable source of forage for many of the scarcer bumblebees that are found at Dungeness at this time of year.

Yellow Flag Iris in the Cladium Pit