ISSN 1067-4136, Russian Journal of Ecology, 2008, Vol. 39, No. 2, pp. 92–98. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © E.A. Kurbanov, O.N. Vorob’ev, 2008, published in Ekologiya, 2008, No. 2, pp. 103–109.
Coarse woody debris (CWD) in a forest stand refers
to dead wood such as dead standing trees, stumps and
snags, and fallen trees or branches with a crosscut
diameter of more than 10 cm, i.e., to woody necromass
at all stages of decomposition, up to transformation into
humus (Harmon et al., 1986; Treifel’d, 2002). The
number of publications dealing with the study of CWD
has increased markedly in recent years due to concern
about climate warming and biodiversity conservation
and the adoption of relevant international conventions
(Harmon et al., 1990, 1994; Amaranthus et al., 1994;
Esseen et al., 1997; Crowford et al., 1997; Hart, 1999;
Bowman et al., 2000; Kurbanov, 2002). Almost
5000 plant and animal species have direct biological
connections with woody debris in forest ecosystems
(Siitonen, 2001). Moreover, only CWD is a suitable
substrate for many endangered species. For example,
28% of red-list macrofungi in Finland are dependent on
decomposing wood (Rassi et al., 1992). Some special-
ists attribute the loss of biodiversity on a global scale to
the dramatic reduction of old-growth forests, which are
a natural environment for the majority of endangered
species (Kirby and Drake, 1993; Bobiec, 2002).
The stock of CWD varies depending of forest-form-
ing tree species, forest type, climate, and stand age
(Demakov, 2000; Kurbanov and Krankina, 2000; Kur-
banov, 2002; Norden et al., 2004; Wilcke et al., 2005).
The main factors providing for signiﬁcant CWD accu-
mulation are natural disasters such as forest ﬁres and
pest or disease invasions. In the subsequent period, the
CWD stock decreases at the middle stages of forest suc-
cession and increases again in mature and overmature
stands (Sturtevant et al., 1997; Siitonen, 2001).
Utilization of decomposing wood by plants and ani-
mals depends not only on the total stock of CWD but
also on the degree of its decomposition and the source
tree species (Harmon et al., 1986; Bader et al., 1995;
Sverdrup-Thygeson and Midtgaard, 1998; Krankina
et al., 1999; Carmona et al., 2002). In turn, the degree
of CWD decomposition depends on tree species and
size, wood quality, and the local microclimate, which
determines conditions for wood-decomposing organ-
isms (Hytteborn and Packhan, 1987; Hofgaard, 1993;
Storozhenko, 2001; Karjalainen and Kuuluvainen,
2002; Kreutzweiser et al., 2005). In boreal forests, the
complete decomposition cycle of a large tree may take
up to 100 years (Hofgaard, 1993). Pine CWD is usually
decomposed less actively that spruce or hardwood
CWD (Krankina and Harmon, 1995).
The pattern of CWD distribution over the forest area
is a factor determining differentiation of the soil cover
in forests (Radyukina, 2004; Tinker and Knight, 2001).
Comprehensive studies performed by several scientiﬁc
teams (Isaev et al., 1995; Usol’tsev and Sal’nikov, 1998;
Shvidenko et al., 2000; Utkin et al., 2001; Usol’tsev,
2002; Zamolodchikov et al., 2005) allowed these teams
to accumulate vast data on the biomass of forest stands
in the boreal zone of northern Eurasia and generalize
them in several theoretical models. Despite the large
number of relevant publications, however, the spatial dis-
tribution of CWD has not been studied sufﬁciently.
Meanwhile, an analysis of spatial variation in the amount
and quality of CWD can provide important information
on tendencies of its accumulation in a forest stand.
The purpose of this study was to estimate the spatial
pattern of CWD accumulation in pine forests growing
in the Transvolga region of the Marii El Republic.
On this basis, it would be possible to draw up guide-
lines for forest management aimed at the conservation
of biological diversity in these forest stands.
Spatial Distribution of Coarse Woody Debris in Pine Forests
of the Marii El Transvolga Region
E. A. Kurbanov and O. N. Vorob’ev
Mari State Technical University, pl. Lenina 3, Yoshkar-Ola, 424000 Russia
Received May 10, 2006
—The spatial distribution of coarse woody debris in pine forests has been studied in the Transvolga
region of the Marii El Republic. For this purpose, 30 test plots have been established in pine (
stands of the study region. The results are indicative of a tendency toward the spatial grouping (clustering) of
woody debris by fractions, decomposition classes, and stocks along with increase in stand age.
: woody debris, spatial point analysis, pine stands, phytomass.