The Botany of Iceland - 01.12.1945, Blaðsíða 67

THE VEGETATION OF CENTRAL ICELAND
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4. THE MEADOW SERIES
To the meadow series I refer the formations whose demands to
moisture are moderate and in which the snow-covering is considerably
above the mean both as to duration and to thickness. This series com-
prises the “vaillendi” (grass field), the “blómlendi” (herb field), and
the “geiri” (snow-patch) of earlier authors. These formations have so
many characters in common that they form a natural series, which
takes its place between the mýri series and the heath series. There are
no sharp limits between the meadow series and the mýri series, since
the jaðar, especially the Calamagrostis jaðar, as stated above, forms the
transition between the two series. On the other hand, transitions to the
two divisions of the heath series, the shrub heath and the Grimmia
heath, are also found. The snow-patches constitute a formation which
in part falls outside the limits of the meadow series, notably the snow-
patches situated at the highest levels or such as have the most prolonged
snow-covering. The snow-patches at lower levels, however, and those in
which the snow-covering approaches the mean, come entirely within the
meadow series, and I consider it unnatural to divide the snow-patches
into two formations. I therefore follow several Scandinavian authors in
referring the snow-patches to the meadow series.
Samuelsson (1917, p. 192) defines the meadow series as fol-
lows: “Zur Wiesenserie rechne ich die Pflanzengesellschaften, wo meso-
phile Graser und Kráuter die Hauptrolle in den Feldschichten spielen
... die Bodenschicht fiir die meisten Wiesen schwach entwickelt... Die
Feldschichten sind zumeist allzu dicht geschlossen, um das Auftreten
einer reicheren Moosvegetation zu erlauben.” A similar definition is
given by H. Smith (1920, p. 41), who says as follows (translated from
the Swedish) : “Plant communities belonging to this [the meadow]
series are distinguished by the herb layer being constituted by meso-
philous herbs and grass; shrubs are lacking. The ground flora is most-
ly slightly developed.” The formations I here refer to the meadow
series fulfil these demands. Grasses and herbs are the most conspicuous
and as a rule form a closed “Feldschicht”. The formations are rich
in species, and the species density is fairly high. Gompared with the
other alpine formations the A percentage is relatively low and the H
percentage high. The “Bodenschicht” is poorly developed except in
a few snow-patches. These formations occur mainly on the lower parts
of the mountain sides, above the shrub heath but below the Grimmia
heath and the fell-field formation. Exceptions are, however, formed by
The Botany of Icland. Vol. III. Part IV.
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