ISSN 1067-4136, Russian Journal of Ecology, 2009, Vol. 40, No. 3, pp. 154–159. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © L.P. Lytkina, S.I. Mironova, 2009, published in Ekologiya, 2009, No. 3, pp. 168–173.
Forests of central Yakutia, especially in alass–taiga
ecosystems, are exposed to the impact of natural and
anthropogenic factors among which forest ﬁres are the
most frequent and destructive. From 1998 to 2005, for
example, the number and area of ﬁres increased by fac-
tors of 1.3 and 5.2, respectively, compared to the period
1990 and 1997 (Lytkina and Protopopova, 2006). Con-
sequently, the number and size of burned-out areas also
Since permafrost is widespread in the region, forest
ﬁres may have irreversible consequences. Therefore,
studies on postﬁre forest regeneration in the cryolitho-
zone are of special importance.
OBJECTS, MATERIAL, AND METHODS
Burned-out forest areas of different ages, at different
stages of succession, and control areas of larch forests
in central Yakutia (Megino-Kangalasskii and Tattinskii
forest enterprises) were studied over seven years
(1998–2004). As in other permafrost regions, these
areas appeared after low forest ﬁres, which lead to sig-
niﬁcant transformations in habitat conditions and in the
composition and structure of plant communities (Pozd-
nyakov, 1963; Utkin, 1965; Shcherbakov et al., 1979;
…, 1994; Abaimov et al., 1996).
Studies were performed by the route and stationary
procedures. In the former case, we used conventional
forest-geobotanical methods (Sukachev and Zonn,
1961) in test plots established in burned-out areas and
in the forest. Forest regeneration in burned-out areas was
studied by the stationary method according to Pobedin-
skii (1966), making forest-geobotanical descriptions in
plots sized 1
1 or 2
2 m (a total of 130) and in
10-m (350) plots. In the course of data processing,
the descriptions were grouped with respect to the age of
the burned-out area: less than 3, 3–15, 15–25, (25) 50–
60, and over 60 years. The last group (larch forest over
60 years of age) was used as the control.
To characterize the composition, structure, and
course of succession, we used parameters such as the
alpha-diversity (Whittaker, 1975; Mirkin and Nau-
mova, 1998), the Sørensen coefﬁcient of similarity
(Mirkin et al., 1989) and the succession dynamism
index (Titlyanova et al., 1993).
RESULTS AND DISCUSSION
Low ﬁres destroy mainly lower forest layers, includ-
ing the herbaceous layer, undergrowth, and tree sap-
lings. The tree layer is usually preserved to a variable
extent (10–90%) but may perish almost completely
because of ﬁre damage to the surface root system.
In central Yakutia, forest regeneration often takes
place in areas where the plant cover was completely
destroyed by ﬁre. Studies on vegetation regeneration
dynamics (in particular, those of herbaceous and
lichen–moss layers) have shown that consistent low
ﬁres in larch forests lead to profound transformations in
the composition and structure of vegetation. In the
Postfire Succession in a Forest of the Cryolithozone:
The Example of Central Yakutia
L. P. Lytkina
and S. I. Mironova
Institute for Biological Problems of the Cryolithozone, Siberian Branch, Russian Academy of Sciences,
Yakutsk, pr. Lenina 41, 677007 Russia;
Institute of Applied Ecology of the North, Academy of Sciences of the Republic of Sakha (Yakutia),
Yakutsk, pr. Lenina 35, 677007 Russia
Received August 13, 2007
—The results of studies on postﬁre succession in larch forests of the permafrost zone are discussed.
The main directions of successional processes in burned-out areas of different ages are described. It has been
shown that secondary pyrogenic successions in larch forests follow the scheme of rapid regeneration without
tree species replacement and the model of succession tolerance. Groups of plant species with different life strat-
egies and indicator species characterizing different stages of the overgrowing of burned-out areas have been
: postﬁre succession, cryolithozone, burned-out areas, regeneration, vegetation, indicator species.