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

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TABLE 10.4
Climate data of the chernozem-steppe.
Sum of mean daily
temperatures over 10°C
Precipitation
mm/year
Grasslands of the world
January, mean temperature
(°C)
Northern Caucasus 3 000-3 500 400-600 0 to -7
Central Chernozem 2 600-3 200 350-500 -5 to -12
Volga Territory 2 200-2 800 300-400 -12 to -16
Ural 2 000-2 900 300-400 -15 to -17
Western Siberia 1 800-2 100 300-350 -16 to -19
Eastern Siberia
SOURCE: Chibilev, 1998.
1 600-2 000 200-400 down to -30
Steppe
The steppe zone covers an area of 143 million hectares. The climate (Table 10.4)
is more continental but becomes more humid towards the foothills of the
mountain ranges (Caucasus, Urals and Altai foothills).
The principal soils of the steppe are chernozems and dark chestnut soils.
However, in the Rostov (Salsk and Primanchy steppe) and Volgograd regions,
as well as in Kazakhstan , solonetz and solonchaks are numerous.
Characteristic of the steppe are treeless plains with a dominance of Stipa spp.
and Festuca sulcata . Trees and shrubs are confined to depressions and ravines
and include Caragana frutex , Spiraea spp. , Amygdalus nana , and Cytisus spp.
Steppe grasses, including the xerophytic types , cease activity in summer and
dry up entirely. With new rains in late August and early September, tillering
recommences. In sharp contrast to the forest and forest-steppe zones , ephemerals
and ephemeroids appear in spring and conclude their cycle of development
in 60–70 days. From the husbandry point of view, the following subdivision
seems useful: 1. Virgin steppe and old fallows . 2. Mid-term fallows of 2–3 to
7–10 years. 3. Young fallows.
Virgin steppe
Only small isolated islands of steppe were preserved in the European part of the
FSU: Askaniya, Starobelsk, Khrenovskaya, Streletskaya (Olikova and Sycheva,
1996). Larger areas used to occur in Russia in the Salsk and Primanchy steppe
in Rostov Oblast [region], in Volgograd Oblast and in Stavropol Kray. Closer
to the Caspian Sea, in the northern parts of the Dagestan Republic, stretches
the sandy, semi -arid Nogayskaya steppe. The largest areas are in Kazakhstan ,
but, apart from the solononetz and solonetzic soils, millions of hectares were
sacrificed to cropping in the 1950s and 1960s.
As pointed out earlier, the distinguishing lines between the vegetation of
virgin steppe and old abandoned fallows are blurred, so that much of the
uncropped land may soon return to steppe and not bear much sign of having
been cropped for so long. The underlying processes that help to facilitate this
return are emphasized here, with a focus on the work done in the period when
virgin steppe still formed a formidable grazing and hay resource.