Janderková Jana, Matějů Jan, Schnitzerová Petra, Petruš Josef, Sedláček Jan, Uhlíková Jitka (2011):
Soil characteristics at Spermophilus citellus localities in the Czech Republic (Rodentia: Sciuridae) [Charakteristika půd na lokalitách sysla obecného (Spermophilus citellus) v České republice (Rodentia: Sciuridae)]:
Lynx, nová série, 42: 99–111.

Abstract

Many rodent species, including ground squirrels, inhabit underground burrows used as a shelter for night, protection from predators and adverse weather, for reproduction or hibernation. Although soil is an important part of environment of the critically endangered Spermophilus citellus, almost no data on this habitat component are available. In 2008 and 2009, basic pedological survey was carried out at 34 extant and four recently extinct localities of S. citellus in the Czech Republic. Altogether 43 test pits were excavated at the study localities. Basic soil characteristics were described, such as taxonomic affiliation – soil group with qualifiers order, suborder or variety, thickness, colour, structure, presence and type of soil skeleton and moisture. In the samples taken, soil texture and basic physical characteristics (maximum capillary water capacity, minimum and actual air capacity, bulk density and porosity) were determined and vulnerability of the soil towards pedocompaction was assessed. Most often, deep soils free of skeleton originating from loess and loess soils loam (39% of test pits), but also shallow soils with a high content of skeleton were recorded. Mean soil depth was 70 cm. No semi-hydromorphic and hydromorphic soils were recorded. Soils with medium and light texture (65% of test pits) prevailed at the study localities, however, rather heavy soils were also represented. Very light and very heavy soils were recorded only marginally. Most of the soils showed good water retention and usually medium aeration. Vulnerability of the soils towards pedocompaction was evaluated as medium in most cases. In summary, S. citellus is quite adaptable to soil conditions, avoiding only soils affected by water. Current distribution of the species in the Czech Republic is thus probably not directly determined by soil conditions.