*2: Tregawn, Withiel,
1889, RVT (B) (Paton 1969a: 732). This record
is older than that listed as new for vc2 by Warburg (1961:
168).
S.
ampullaceum is a widespread moss in upland regions of
northern and western Britain where it
grows in small patches on dung of cattle, sheep and deer on
wet heaths, moorlands and bogs. Investigations of the ecology
of this and other species of Splachnum (summarised
by Koponen 1990
and Marino 1997) have showed that a strong odour from their
ripe capsules attracts dung flies, resulting in dispersal of
the sticky spores to the widely scattered patches of herbivore
dung.
During the 1960s S. ampullaceum was
frequent on Bodmin Moor (SX17, SX18, SX27), with isolated
records also from Rosenannon Downs (SW96N) and E. of Woolley Barrows
(SS21T). It grew in small patches on dung on wet heaths and in
boggy valleys and was frequently fertile, with capsules mature
7-8 (Paton 1969a: 732).
There have been no records since then despite
extensive surveys of the bryophytes in mires on Bodmin Moor,
so the species must now be feared extinct in Cornwall.
Disappearance of the species from most of its former range in
south-eastern England over the past century has been
attributed to habitat destruction through drainage (A.C.
Crundwell in Hill et
al. 1994: 48), coupled perhaps with a decline in the
grazing of stock on common land and village greens (Cox 1999:
35). However, these factors seem unlikely to be responsible
for its recent loss from Bodmin Moor which still has extensive
mires and stocking levels that are too high in many areas.
Instead, it is feared that loss of S. ampullaceum may be an
indirect result of the widespread use since the 1980s of
ivermectin (an avermectin; used as an endectocide) to remove
helminths and other gastrointestinal parasites from domestic
stock. Very low concentrations of these drugs kill dung flies,
and it is now established that ivermectin usage has caused
large and widespread declines of these and other coprophilous
insects (Cox 1999: 34). Loss of the community of insects
responsible for breakdown of herbivore dung has resulted in
longer persistence of the dung, which might have been
beneficial for Splachnum were it not
for the concommitant loss of the dung flies that disperse the
moss spores.