Pochválovská stráň National Nature Reserve

The Pochválovská stráň NNR is a notable geomorphological phenomenon in the west of the Středočeský kraj- Central Bohemian region, to the north of the town of Rakovník and near the villages of Pochválov and Smilovice. The protected area was declared in 1989 on an area of 24.3 ha. The main subject of the protection is the natural communities of the marlstone outcrops with the occurrence of the alpine bearberry and shrubby milkwort, natural thermophilous shrub growths, thermophilous oakwoods and talus and ravine forest.

The NNR lies on the north-western edge of the Džbán plateau, which is built of  Cretaceous rocks. The reserve includes a steep marlstone (opoka) rock scarp with the neighbouring slopes and the high peneplain. The national nature reserve stretches along the north-west facing slopes and is around 1.8 km in length but only 85 m wide at its narrowest point.
 
The most valuable parts of the territory are the very steep to perpendicular marlstone (opoka) cliffs with cushion colonies of alpine bearberry (Arctostaphyllos uva-ursi). The natural vegetation cover was probably of thermophilous (subxerophilous) oakwoods, which is indicated on the forest fringes and in glades by the occurrence of the Irish fleabane (Inula salicina), bloody cranesbill (Geranium sanguinea) and bastard balm (Melittis melissophyllum). At present, the plateau above the scarp slopes is decalcified and supports acidic oakwoods with Scots pine (Pinus sylvestris), together with shrubby milkwort (Polygala chamaebuxus), bilberry (Vaccinium myrtillus) and cranberry (Vaccinium vitis-idaea). On the cliffs where fresh areas of marlstone are exposed we can findgrasslands, which have a similar species composition to the so-called “white slopes”. These grasslands gradually pass into open canopy stands at the foot of the scarps with hazel (Corylus avellana), dogwood (Cornus sanguinea), Scots pine (Pinus sylvestris) and small-leaved lime (Tilia cordata). Other species which grow here are blue moor-grass (Sesleria caerulea), common wintergreen (Pyrola minor), the Bavarian bastard toadflax Thesium bavarum and the smelly wallflower (Erysimum odoratum). In the talus and ravine forests we can find variegated monkshood (Aconitum variegatum), with mezereon (Daphne mezereum) and European columbine (Aquilegia vulgaris) in places, in addition to cornelian cherry (Cornus mas) and the St.Bernards lily (Anthericum ramosum). The critically-endangered small limestone moss Seligeria campylopoda which was found here in 2000, only grows in the Džbán hills, Hostýn Hills and Krkonoše Mountains on the territory of the Czech Republic.
 
The geological basement is of Bílá Hora Opokas from the Lower Turonian, which lie on softer glauconite marls, under which there are Cenomanian sandstones, which have been uncovered by a landslide in the central part of the territory. The older Permian-Carboniferous strata are not visible in the territory as they are covered by landslides and rockslides.

This is a territory which lies on the geomorphological border of one of the structural plateaux of which the whole Džbán region is built and on the western edge of this plateau. The highest part of the NNR is the almost horizontal edge of the structural plateau at 472 – 489 metres which ends in a sharp morphological line of landslide scars – under which we can find a near-vertical and more than 20-metre-high rock-scarp formed of spiculitic marlstone (opokas). The foot of this slope is covered to various heights witha lining of thick landslide bodies, the fronts of which are far below the borders of the NNR. The mass movements are still active, as we can see from the sabre-shape of most of the trees and also the sunken surface levels of the detaching blocks which are in the process of breaking off from the upper edge of the slope and the dilated joints in the cliff below them. Landsliding follows liquefied clays underlying the marlstones and the sliding masses form a very uneven surface with a local height difference of several metres between the crests and bases of the individual landslides.
 
A rich community of forest molluscs lives among the rock falls at the foot of the walls. The dominant gastropod is the hairy snail Helicodonta obvoluta and other sensitive typical forest species include the Orculid snail Sphyradium doliolum, the glass snail Aegopinella pura, the typical snail Isognomostoma isognomostoma and the door snail Macrogastra plicatula. The marlstone rock-scarps play host to characteristic communities with the door snails  Laciniaria plicata and Clausilia dubia.
 
Pochválovská stráň NNR lies in an area with a long settlement history and more accessible areas were economically utilised over many centuries. Animal bedding was gathered here, animals were grazed here and stone was probably quarried too. Evidence of prehistoric settlement has been found near the western edge of the reserve, where remnants of the defensive banks and foundations of the Slavonic Dřevíč fortress can still be seen today. The current forest stands have a modified species and spatial structure and were mostly planted as commercial forests.

No marked tourist trails lead to the reserve and it is not open to the public. A forest trail leading from the village of Pochválov passes close to the reserve and offers views over the landscape around the town of Louny.