Antitrichia curtipendula, Neckera pumila, Zygodon conoideus. Cryphaea heteromalla, Ulota crispa,
and Orthotrichum lyellii, have long since gone from the Forest, but Tortula laevipila and Homalia
trichomanoides are relatively recent losses. With the dramatic fall in SO2 in recent years, however, we
can hopefully look forward to the return of some of these epiphytes.
Hypnum cupressiforme var. resupinatum, Amblystegium serpens, Brachythecium velutinum, B.
rutabulum, Isothecium myosuroides, Lophocolea heterophylla and surprisingly, Hypnum
mammillatum seem to have survived the worst of the pollution, but species such as Homalothecium
sericeum, Neckera complanata and Zygodon viridissimus, only survived in any abundance in
raintracks fed by hollow bosses (filled with a neutralising slurry of rotting leaves), on a handful of
reclining beech trees. Otherwise they were only to be found as tiny scraps on gnarled roots, well away
from the acid ram ducted down the trunks from the canopy.
Zygodon forsteri, our most famous Essex moss, now on the national Red Data list, has its U.K. and
probably its European stronghold, in the hill-top beechwoods of Epping Forest. It fluctuates markedly
in abundance from year to year, depending on the annual rainfall, and grows exclusively on old gnarled
beech trees in Great Monk Wood, with a few isolated colonies in Little Monk Wood and the Upper
Wake Valley. Prior to the 1987 hurricane it occurred in quantity in extensive raintracks fed by
humus-filled bosses in the crowns of three reclining beeches. Deprived of their canopies by the gales,
these trees and their Zygodon colonies, are slowly dying. The remaining Z. forsteri patches are
ephemeral, and confined to knarled bosses and tree roots, where they compete with grey squirrels for
the smooth callus around knotholes, often growing in the grooves gnawed by the latter only to be
removed by them the following year.
Birch and oak have a more acid bark than beech or hornbeam, and on their stumps and lower trunks
the acidophil Tetraphis pellucida and Orthodontium lineare predominate, particularly encouraged on
the Forest by over a century of acid rain.
O. lineare is a sub-tropical alien, first discovered on the Forest in 1946, since when it has explosively
colonised the U.K. to become a ubiquitous moss of tree bases and peaty banks over a variety of soils.
Curiously. Tetraphis on the other hand is only found where its phorophytes grow on markedly acid
soils. In some way as yet unknown, the soil type must influence the nutrient status of the bark on
which it grows. Rarely found fruiting, and then only in well-lit clearings, Tetraphis colonises new
sites by the copious production of vegetative gemmae, borne in terminal splash cups.
In the 1920 s the rare leafy liverwort Ptilidium pulcherrimum became established on at least six
trees on the Forest. Today it is still to be found on the very oak that J. Ross described it on in 1917,
but it has yet to be rediscovered elsewhere. A more recent newcomer. Dicranum tauricum, which
propagates from its fragile leaf tips, is now abundant on logs and tree branches on the Lower Forest
north of Epping: and in a broad swathe south from the Bell Common tunnel to Ambresbury Banks;
with an outlier on Blackweir Hill.
The once extensive heathy grasslands of Long Running. Jacks Hill and Deer Shelter Plain, are now
largely scrubbed over by birch, and the small remaining patches, thanks to the demise of deer and
rabbit, are a virtual monoculture of the coarse Purple moor-grass, Molinia. Typical heathland
bryophytes such as Pleurozium schreberi. Pseudoscleropodium purum. Rhytidiadelphus squarrous,
Dicranum bonjeanii (damp hollows). Campylopus pyriformis and Gymnocolea inflata, are still to be
found on the Forest though in ever decreasing quantity. The S02 sensitive Hylocomium spendens.
Rhytidiadelphus loreus. R. triquetrous and Bartramia pomiformis are all however extinct. P. schreberi
is declining in abundance through continued loss of suitable damp heathland habitat, while D.
bonjeanii is now only sproadic in appearance and dependent on a wet autumn and spring. Both are
likely to become extinct over the next few years.
Prior to the levelling, drainage and metalling of some 22 miles of Forest rides during the 1970 s
and 1980 s. the leafy liverworts Scapania irrigua. S. nemorea. Nardia scalaris. Jungermannia
(Solenostoma) gracillima, Fossombronia wondraczekii and F. pusilla together with the mosses
Pohlia annotina and P. wahlenbergii, were frequently found along the more open well-lit rides in hoof
holes, wheel ruts and marshy borders. Today these species together with the vascular plants; Hard
fern. Round-leaved Sundew, Lousewort and Golden Rod, are all but extinct through loss of habitat,
though once widespread along the Forest rides.
The deep steep-sided drainage ditches accompanying the metalled rides provide a unique moist
habitat however, particularly where vegetation overhangs the margins. Ephemeral colonies of
Pogonatum nanum. P. aloides. Riccardia chamedryfolia and Dicranella cerviculata occur here from
time to time, together with large luxuriant colonies of common bryophytes such as Pellia epiphylla
and Atrichum undulatum.
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