Friday, December 21, 2012

East European Forest Steppe (7)


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The forest steppe is the area marked '11' here
There is some confusion in the literature over where the East European forest-steppe begins and ends. Some sources (such as Rusnature.info)  suggest that as part of the high biodiversity of the deciduous forests of the East European plain, there is an east European broadleaf forest zone between the Sarmatic Mixed forest  and the forest-steppe itself, while others treat these two zones as the same. It is treated as a single zone by the World Wildlife fund, so this is the solution adopted here.  


The East European Forest steppe extends from the eastern foothills of the Carpathians in Romania in the west to the Ural Mountains in the east. It forms a series of transition ecoregions between the temperate broadleaf and temperate mixed forests and grasslands biomes (the Central European and Sarmatic mixed forests to the north and the Pontic-Caspian steppe to the south). On the Middle Volga and in the Southern Urals, the strip of forest is about 150 kilometers in width. The zone comprises a combination of forest and grassland sites, and includes areas characterized by the highest biodiversity within the deciduous forest zone of Northern Eurasia.

The composition of deciduous forests changes notably across the region. In the western regions and the European part of Russia, Central European deciduous species occur. In the westernmost areas (the Carpathian foothills and lower slopes), Beech (Fagus) stands with a small admixture of Sycamore Maple (Acer pseudoplatanus), Oak (Quercus petraea), and Lime (Tilia tomentosa) occur. Lime is less common in the habitat than in the past, this due to athropogenic changes (cattle grazing and fibre production). These forests have thick litter, supporting shade-enduring plants, but an almost complete absence of undergrowth. The herbaceous cover is represented only by nemoral species.

Beech forest in Carpathian Mountain foothills (Encyclopedia of Ukraine).

Further east, in the European part of Russia, the vegetation is dominated by Oak (Quercus petraea) forest with an admixture of other species including Ash (Fraxinus excelsior) Beech (Fagus sylvatica), Hornbeam (Carpinus betulus), Lime (Tilia tomentosa), Sweet Chestnut (Castanea saliva), Sycamore Maple (Acer pseudoplatanus), sometimes together with coniferous species Slver Fir (Abies alba) and Swiss Pine (Pinus cembra). The shrub layer comprises Hazel (Corylus avellana), Cornelian Cherry (Cornus mas) and Spindle (Euonymus europaeus). The Central Russian deciduous forests are best preserved in the belts of preserved primary forests, several kilometres wide called 'zaseki', which served as a protection from the Medieval Mongol invasions.

According to the Encyclopedia of the Ukraine:
A warm summer and a moderately cold winter are characteristic of the forest-steppe. The climate becomes more continental towards the east; the average July temperature is 18°C in the west and 20°C in the east, while the average January temperatures are –4°C and –8°C. The number of days above 0°C is 230 in the northeast and 270 in the southwest. The number of days above 5°C is 190 and 220. Annual precipitation is usually 450–550 mm in the east and 550–700 mm in the west. Eighty percent of the precipitation falls when the temperature is above 0°C. In the summer the rain comes in downpours. The main soils of the belt are deep chernozems and high-humus chernozems (particularly in the southern regions), some of which have been degraded into podzolized and meadow chernozems and gray podzol soils under the influence of forests.


A forest in Ukraine's forest-steppe region  (Encyclopedia of Ukraine).


A forest-steppe landscape in Poltava oblast (Encyclopedia of Ukraine)


Velikoanadolskiy Forest on Donetsk steppe - not actually forest steppe per se  (Ukraine Adorable Land)

Velikoanadolskiy Forest on Donetsk steppe - not actually forest steppe per se  (Ukraine Adorable Land)
The occurrence of Central European species decreases gradually from west to east, and participation of Siberian species increases. Hornbeam disappears first, and further eastwards Ash. In  Zavolzhje - Maple and Elm become more frequent, while in Asia their position is taken by Birch and Aspen (Populus tremula), with an admixture of pine and larch (Larix sp.).

The fauna of this zone comprises a mixture of forest and steppe species: forest martens, squirrels, dormice, occasionally encountered are elk, deer, ground squirrels, jerboa (earth hare), marmots, steppe polecat, bustard, little bustard, in the rivers - the beaver and muskrat.

Sources:
Rusnature.info,'Mixed and Deciduous Forests of the East European Plain'.

Volodymyr Kubijovyč, 'Forest-steppe' Encyclopedia of Ukraine, vol. 1 (1984)

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