1067-4136/01/3201- $25.00 © 2001
Russian Journal of Ecology, Vol. 32, No. 1, 2001, pp. 22–28. Translated from Ekologiya, No. 1, 2001, pp. 25–32.
Original Russian Text Copyright © 2001 by Stasyuk.
The Terek River delta is characterized by the most
intense land use among the alluvial plains of the Cas-
pian Lowland, and the problem of the anthropogenic
evolution of its soil cover is central in studies on delta
soil formation. The analysis of the spatial and temporal
dynamics of soil salinization is especially important:
this process eventually determines the ecological state
of soils, as more than 90% of them contain salts at dif-
ferent depths and in different amounts.
MATERIALS AND METHODS
Long-term studies on the soil cover in the delta basi-
cally consisted in mapping the soils and their saliniza-
tion in ten key land plots with a total area of 140 000 ha.
This work was performed twice, at a 20-year interval,
in each taxon of the soil-ecological zoning of the delta
(ﬁgure) by the same method of large-scale on-land
mapping with the use of aerial photographs. The result-
ing maps made at different periods of time were com-
pared with analogous maps made in the 1930s.
In addition, the comparative analysis of soil-geobo-
tanical maps and maps of land use over the past
60 years was performed (Vinogradov and Tolchain,
, 1934; Chilikina
, 1975, 1991a, 1991b; Molchanov
, 1987). Temporal changes of the soil cover were
studied in areas differing in conditions and methods of
land use. In the delta, these are irrigated lands, irrigated
and ameliorated lands under rice, and lands used as dis-
tant ranges for livestock breeding.
The speciﬁc features of the soil cover in the delta are
as follows: type diversity of evolutionarily related soils;
salinity; heterogeneity with respect to age, composi-
tion, and salinization in a greater part of the area; and
dynamism (instability) of the spatial pattern. Alluvial
calcareous soils with recent or relic hydromorphism are
dominant. They include meadow-bog and meadow
soils, solonchaks (meadow, anciently hydromorphic,
typical, hummocky, and puffed), light chestnut and
meadow light chestnut soils, and irrigated bog soils.
Their proportions in the soil cover vary in different taxa
of zoning; however, meadow soils dominate in the allu-
vial region and typical solonchaks dominate in the sea-
side region. Light chestnut relic-hydromorphic soils
cover 12% of the delta, on average. The soil cover of
the alluvial region has a more complicated pattern
(Table 2), as it mainly consists of small areas with dif-
ferent soils. A sharp structural contrast is most apparent
in the soil cover of the ancient delta areas of both the
alluvial and seaside regions (Tables 2, 3; subregions
Temporal Dynamics of Soil Cover Salinization in the Terek Delta
N. V. Stasyuk
Moscow State University, Vorob’evy gory, Moscow, 119899 Russia
Received December 17, 1999
—The results of long-term land use in the Terek delta was analyzed, including the temporal anthro-
pogenic dynamics of the soil cover and its salinization. A matrix description of salinization dynamics was given,
and the prognosis of further changes in the soil cover was made.
: delta, soil-ecological zoning, soil cover, salinization, spatial and temporal dynamics, matrix
description, prognosis, land use.
Scheme of soil-ecological zoning of the Terek delta (Dobro-
, 1975; Stasyuk and Fedorov, 1994): (
ecological region of alluvial plains with the subregions of
) degradational differentiation, (
) anthropogenic trans-
formation and degradation, (
) degradation, and (
) soil-ecological region of the accumula-
tive marine plains with the subregions of (
degradational differentiation, (
) transgressive degrada-
tion, and (
) focal desertiﬁcation of the soil cover.