Fróðskaparrit - 01.01.2007, Blaðsíða 119

GRÓÐURIN Á FLAGTEKJUM í FØROYUM OG Á GRASLENDINUM UTTANUM
- EIN KANNING ÚR SANDOYNNI
117
more typically, birch (Betula spp.) bark
was imported from Norway and placed be-
neath the turfs to provide a waterproof
layer (Taylor, 1997). Constructed in this
way the turf roofs would remain servicea-
ble for 40 to 60 years whereas the barley
thatch would be renewed at more regular
intervals of 4-5 years (Stanley in West
1976).
At the start of the twentieth century, Os-
tenfeld (1905-1908, p. 1012) observed,
“that nearly all the Færoese houses are
thatched with turf.” By the middle of the
century, Williamson (1948) obseiwed the
removal of turfs from the roofs in Koltur
and their replacement with asbestos sheets.
This replacement of turf by more modern
materials has continued throughout the
Faroes, so that by the end of the twentieth
century only outbuildings and occasional
modem houses were roofed in such a way
(cf. Hansen and Jóhansen, 1982). How-
ever, with a few exceptions (e.g. Dúvugar-
dur museum in Saksun), the traditional ap-
pearance of these remaining roofs belies
their more modern mode of construction
that incorporates plastic sheeting in place
of the more traditional birch bark (næver).
The species composition of the turfs
initially reflects that of the vegetation it is
removed from, usually within the outfíeld
or hagi (Ostenfeld, 1905-08). Attention has
been drawn to the decreasing plant diver-
sity of the turfs once they are lain upon the
roof and this has been presumed to be a
consequence of summer drought condi-
tions favouring a predominance of grasses
over the other phanerogams and associated
cryptogams (Lyngbye, 1822; Ostenfeld,
1905-08; Hansen, 1966; Hansen and Jó-
hansen, 1982). In some cases, the vigorous
growth of the grasses could be harvested to
supply hay (Hansen and Jóhansen, 1982)
and chickens would also exploit the roofs
as they searched for food (Williamson,
1948).
The grass species prevalent on the roofs
are those that are best able to tolerate the
presumed limiting factor of summer
drought, such as Anthoxanthum odoratum,
Festuca rubra var. fratercula and Poa triv-
ialis (Jóhansen, 1985). While some or all of
these taxa may have lieen present in the
vegetation of the original turf, and it may
have been chosen for this reason, it was a
common practice to collect seeds or grown
plants of desirable species for incorpora-
tion into the roof. F. rubra var. fratercula or
Poa trivialis were especially favoured, pre-
sumably because of the waterproofing pro-
vided by the long, procumbent and “flow-
ing” habit of the leaves of these grasses.
Aims and hypotheses
The first aim of this paper is to offer some
observations and data on an interesting as-
pect of traditional Faroese building that is
currently in the process of becoming lost to
more modem materials and methods. ln so
far as the data sets allow, the paper also in-
tends to test three hypotheses concerning
the lower species diversity of the roof turfs
in comparison to the ground vegetation
from which they were probably derived:
Hypothesis one: there is a reduction of
species diversity due to summer drought
conditions (this was proposed informally