Grasslands of the World.pdf - Disasters and Conflicts - UNEP

The Russian Steppe 399
MEADOW TYPES
Liman
Due to the exceptional flatness of the surrounding area, semi -desert rivers
that spread out over enormous areas in spring often never reach the Caspian
Sea, and form the meadow areas called limans (Mamin and Savel’eva,
1986). Such areas can be 30–40 km wide, but shallow enough for wheeled
transport to pass. Intense evaporation and high watertables promote the
development of solonchaks and solonetz, with predominance of halophytes
or tolerant plants (Artemisia spp. (Plate 10.6), Puccinellia spp. , Atriplex
verrucifera and Agropyron repens ). Patterns of concentric rings emerge,
with water receding from the perimeter towards the centre, a pattern that
is reflected in the vegetation . Artemisia monogyna and Atriplex verrucifera
are in the outer rings that are rarely flooded and then only for a few days.
The area may be hundreds of hectares in size. Further towards the centre,
the rings or strips flooded once in two to three months with water in a layer
of 30–60 cm until June/July produce stands of almost pure Agropyron spp.
that grows up to 150 cm and gives hay yields of 6 000–7 000 kg/ha. The
centre and lowest parts of the liman may consist of reed thickets. In the
FSU, limans used to occupy over 7 million hectares. Needless to say, limans
are of great economic significance in the Saratov and Volgograd region, and
may take much of the pressure off the surrounding catchment grazing areas.
Only minor ditches need to be constructed to lead water to areas with the
most valuable fodder plants (Agropyron repens, Agropyron pectiniforme and
Euagropyron spp., with Medicago sativa ssp. falcata, Bromus inermis and
Beckmannia spp. ).
Typical plants of the favourable parts of the sandy (loam) stretches
are Artemisia arenaria , A. astrachanica , Carex colchica , Kochia prostrata ,
Agropyron sibericum , Stipa capillata and S. joannis . In lower places, the water
table may be at 100–200 cm. Agropyron sibericum is the most valuable grass in
this environment, yielding up to 1 000 kg DM/ha. Heavy grazing is believed
to pulverize the top soil and increase Agropyron sibericum at the expense of
Artemisia astrachanica.
Floodplain meadows
The steppe is traversed (Plate 10.7), in a north-south direction, by some of
Europe’s largest rivers. When in spate, large areas on either side are inundated.
First in early spring , with the snow melting in the region itself; second, in late
spring, when the waters of snow melting in the north arrive. Flood meadows
are found over the whole length of the river course. The limans, in contrast, are
confined to the lower reaches and in flat semi -desert country.
In the FSU, the total area covered by floodplain meadows (Plate 10.8) was
over 30 million hectares, divided equally between hay and grazing . Their value
is rated higher the drier the nearby catchment. As with the limans described