Matějů Jan, Šašek Jan, Vojta Jaroslav, Poláková Simona (2011):
Vegetation of Spermophilus citellus localities in the Czech Republic (Rodentia: Sciuridae) [Vegetace na lokalitách sysla obecného (Spermophilus citellus) v České republice (Rodentia: Sciuridae)]:
Lynx, nová série, 42: 133–143.

Abstract

The European ground squirrel (Spermophilus citellus) is a typical inhabitant of the steppe but it also occurs in a variety of man-made habitats such as pastures, lawns or sports fields. In our study we attempt to present a complete survey of vegetation types and environmental conditions on recent ground squirrel localities in the Czech Republic. We carried out vegetation research of 42 localities and recorded 110 phytocoenological relevés at the sites recently occupied by ground squirrels. The relevés were classified using the Twinspan classification and general patterns of vegetation were analysed using the principal component analysis (PCA). Environmental factors were assessed using the Ellenberg indicator values. The classification analysis showed six distant groups of relevés/vegetation types (in descending order according to group size): (i) Cynosurus pastures, (ii) Undifferentiated grasslands, (iii) Xerophilous ruderal vegetation with biennial and perennial species, (iv) Xerophilous natural grasslands, (v) Annual vegetation of arable land, and (vi) Acidophilous grasslands on shallow soils. The PCA showed relation, although limited, of the ground squirrel occurrence to three groups of plant species characterized by (i) Lolium perenne, (ii) Festuca rupicola, and (iii) Poa angustifolia and Festuca rubra agg. The Ellenberg indicator values characterized vegetation present at ground squirrel localities as hemi-heliophilous, sub-atlantic and adapted to average temperature and lower humidity conditions. The soil productivity and soil reaction values were considerably variable. Occurrence of the European ground squirrel in the Czech Republic thus seems to be related rather to low vegetation cover than to habitats possessing some specific plant species or vegetation types.