Sometimes its all about the light, about the light, and mossy woodland...
No really, "Big shaggy moss" is the name of Rhytidiadelphus triquetrus, which grows on calcareous ground in woodland, and also on acidic ground in woods of native pine (Pinus). It can also be found in open grassland on chalk, on sand dunes and in churchyards, so is a natural contender for the Corsican pine and sand dune habitat of Holkam and Wells-next-the-Sea beach and SSSI.