ISSN 2079-0864, Biology Bulletin Reviews, 2018, Vol. 8, No. 3, pp. 203–211. © Pleiades Publishing, Ltd., 2018.
Original Russian Text © A.A. Egorov, A.N. Afonin, 2017, published in Zhurnal Obshchei Biologii, 2017, Vol. 78, No. 1, pp. 67–76.
Ecogeographical Potential of the White Spruce
(Picea glauca (Moench) Voss, Pinaceae),
and the Possibility of Its Introduction into Northern Eurasia
A. A. Egorov
* and A. N. Afonin
St. Petersburg State University, St. Petersburg, 199034 Russia
St. Petersburg State Forest Technical University, St. Petersburg, 194044 Russia
Received May 16, 2016
Abstract⎯We analyzed the factors limiting the distribution of the white spruce (Picea glauca) in North Amer-
ica and the ecological amplitudes of the species in relation to these factors. Based on these data, an ecogeo-
graphical model of spruce dispersal was built. It is shown that the northbound dispersal of White Spruce in
North America is limited by heat supply. The species range is shaped at the southwestern border (from the
central part to the Rocky Mountains) by the lack of humidification and at the southeastern border, presum-
ably, by competitive relations with foliar edificators. For P. gl au ca, the northern limit of heat supply is about
1200°C. At the southern border of the range, the White Spruce has low competitive ability with deciduous
trees, starting approximately from the sum of active temperatures of about 3000°C. The limits of species dis-
persal in arid zones are determined by the hydrothermal coefficient, the value of which should not exceed 1.2.
Validation of the dispersion model for P. gl au ca shows a discrepancy between the actual and model range of
±50–100 km. Formerly unknown populations of P. g l a u ca may be found, as affirmed by a new records of the
White Spruce in the Noatak National Park, within the discrepancy zone, between the potential range and that
ascertained by Little (1971). We compared the ecological boundaries of P. g la uca dispersal with those bound-
aries of the genus Picea in Eurasia. It was found that ecogeographical model designed for P. glauca describes
the dispersal of Eurasian spruce species with high accuracy. This was evidence that the ecological divergence
between North American and Eurasian spruce species was not strong. Deviation of the modeling results for
the White Spruce from the actual Eurasian spruce range was observed in the regions with permafrost and
some others. Therefore, additional environmental factors are required for the ecogeographical model upon
its introduction to another continent.
At the beginning of the 20th century, Mayr (1925)
expressed the theoretical assumption that plants may
be introduced from their natural range into regions
with a similar climate. Developing his theory,
Cajander (1923, 1926) and Ilwessalo (1926) proposed
combining Mayer’s induction method with a tradi-
tional experimental approach based not only on data
on unplanned plant introduction but also on the anal-
ysis of the natural (mainly, climatic) conditions of the
natural range and area of introduction (Maleev, 1933).
For preliminary estimation of plant introduction suc-
cess, Maleev (1933) proposed the use of climatic and
phytogeographic methods, i.e., those based on the
similarity of vegetation types and their life forms.
Sufficient material has been accumulated to date
on the spatial distribution of environmental climatic
factors, which may serve as the basis for ecological and
geographic analysis and modeling of their distribu-
tion. In this paper we analyzed the methodical aspects
of the determination of the ecological and geographi-
cal potential of spruce trees (Picea glauca (Moench)
Voss) growing in northern North America and used
modified methods of climatic analogs to determine its
potential range in northern Eurasia.
The main ecological factors limiting the distribu-
tion of arboreal plants are as follows (Afonin and Li,
2011; Egorov et al., 2014; etc.):
(1) Unfavorable winter conditions, primarily, low
temperatures, which lead to plant freezing;
(2) Low heat provision and short vegetative period,
which does not allow plants to undergo the complete
seasonal cycle of development, form offspring, or pre-
pare for winter;
(3) Moisture deficiency.
Edaphic characteristcs, in particular, the presence
of frozen horizon in the soil, may be a regional factor
influencing the distribution of arboreal plants.