ISSN 1067-4136, Russian Journal of Ecology, 2008, Vol. 39, No. 4, pp. 299–301. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © I.A. Goncharova, 2008, published in Ekologiya, 2008, No. 4, pp. 315–317.
Mosses have efﬁciently adapted to dehydration and
can resume normal functioning after the water deﬁcit is
over, without any noticeable harmful consequences.
Each live cell of moss can survive long-term drying to
the air-dry weight in a plasmolyzed state (Tumanov,
1929). The amount of hygroscopic moisture (water that
ensures the survival of dehydrated mosses and is
released upon heating at 100–105
C) varies in different
species of mosses and characterizes the moss moisture
in the air-dry state. This amount of water, which is the
amount that has to be additionally evaporated for the
plant to reach the absolutely dry weight, depends on the
ratio between the amount of strongly bound water,
which can be removed only at a high temperature, and
the amount of weakly bound water readily evaporating
at room temperature (Arinushkina, 1961). Analysis of
the hygroscopic moisture contents of various species of
mosses is important for evaluation of their resistance to
The study was performed at a forest–bog station of
the Sukachev Institute of Forestry of the Siberian
Branch of the Russian Academy of Sciences located in
the Timiryazevskii District Forestry of Tomsk oblast in
the northern part of the Ob–Tom’ interﬂuve during four
ﬁeld seasons. The objects of the study were located in
bogs with different water–mineral trophic statuses: oli-
gotrophic, oligomesotrophic, and eutrophic.
The following species of mosses were sampled from
bogs of different types: from oligotrophic bogs,
(Russ. ex Russ.) C. Jens.,
(Brid.) Mitt., and
Brid.; from oligo-mesotrophic bogs,
Hedw.; and from eutrophic bogs,
C. Jens. ex H. Arnell et C. Jens.,
(Web. et Mohr.) Warnst.,
(Hueb.) T. Kop.
The species composition of the mosses was deter-
mined using the
Key to Leafy Mosses of Tomsk Oblast
(Mul’diyarov, 1990); the specimens were examined by
means of an MBS-9 binocular magnifying glass and an
MBI-3 microscope. The names of the mosses are indi-
cated according to Ignatov and Afonina’s (1992) anno-
tated list of bryophytes. Samples of mosses (in ﬁve rep-
licates) were dried at 100–105
C. The hygroscopic
moisture content was calculated according to Arinush-
is the hygroscopic moisture content,
weight of evaporated water, and
is the weight of the
moss sample in the absolutely dry state.
mosses substantially differed
in the hygroscopic moisture content (Fig. 1). Most
mosses studied (except for
) have no ana-
tomical adaptations, such the cuticle, fuzz, etc. Their
water-retention capacity is accounted for by their phys-
iological and morphological characteristics.
Green mosses lost from 1.7 to 5.5% of water upon
the transition from the air-dry to the absolutely dry
had the lowest hygro-
scopic moisture content (1.7%). In other words, plants
of this species lost almost all water upon drying to the
air-dry state; hence, most of the water was weakly
bound. The low water-retention capacity of this species
is determined by a low content of strongly bound water.
In the mosses found on prominent elements of the
microrelief of oligotrophic bogs (
), the hygroscopic mois-
ture content was almost twice as high as in mosses
grown in eutrophic bogs (
). In oligotrophic bogs,
ground water is 10–50 cm below the surface.
mosses readily take up water via hyaline cells,
because the bottom ends of their stems reach deep into
the substrate. Since 60–75% of the water content of the
The Hygroscopic Moisture of Mosses in Bogs of Tomsk Oblast
I. A. Goncharova
Sukachev Institute of Forestry, Siberian Branch, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036 Russia
Received May 31, 2006
: green mosses, sphagnum mosses, hygroscopic moisture.