| Bryophytes Bryophytes
are surely the Cinderellas of the plant world; they are there in the background
but they are unseen. Look under the next patch of Nettles and you will very likely
find masses of the big moss Brachythecium rutabulum. There will be more moss plants
than nettles and quite possibly the moss will have the greater biomass: but to
many people, there are just nettles. And yet bryophytes are often of ecological
importance as colonisers. The sand dunes of the Sefton and Flyde coast are justly
famous for their flowering plants; but how does vegetation get established in
shifting, wind-blown sand? Look in loose sand around the Marram grass and you
will find clumps of the beautiful gold-green moss Tartula ruraliformis binding
the sand and providing a foothold for bigger plants. The
moist slacks on thelandward side of the Sefton dunes are the home to a number
of rare bryophytes of National and even European importance. Several of these
are species of Bryum, superficially resembling Bryum capillare which is common
on many wall tops and conspicuous for its large drooping capsules, but it is difficult
to distinguish the different species. However, there is no mistaking our prize
liverworts of the dune slacks, Petalophyllum ralfsii; the problem is finding it!
Although spectacular it is tiny, and best searched for on hands and knees. This
species and some of the Bryum species are protected by law and must not be interfered
with in any way. The
Trough of Bowland and the South and West Pennines provide a range of bryophyte
habitats and a remarkable diversity of species; this has been quantified in recent
surveys by counting species numbers in 2km square areas (tetrads). Among the richest
areas are deep rocky cloughs with fast-flowing streams, especially those with
woodland. Many tetrads in Bowland have well over 100 species and around Leck Beck
there are a couple of tetrads with well over 200 species. Even the Pennines fringes
adjoining industrial areas are remarkably rich, with around 100 species in the
tetrads containing Lead Mines Clough (east of Chorley) and Gorpley Clough near
Todmorden. In such habitats one finds some spectacular large mosses such as Dicranum
majus and Ryytidiadelphus loreus and the streams will have big green cushions
of liverwort Scapania undulata and perhaps Nardia compressa which is nationally
rather scarce but quite frequent in Lancashire. The
moorland around these rocky cloughs is generally less species-rich but there is
still much of interest. In particular, the springs and flushes have beautiful
and colourful green Philonotis fontana (often with spherical capsules above the
slick-like shoots) mingle with patches of bright green Dicranella palustris, and
it is likely there will be Bryum pseudotriquetrum, darkish green touched with
red. If there is wet rock, perhaps around a little waterfall, it may be draped
with coppery-brown Sphagnum denticulatum. Many bryophytes are, like litchens,
sensitive to air pollution. Any naturalist who learns to recognise these interesting
mosses can make useful records of their recolonisation of our country. | |
