We are restoring the splendour of Kruczy Kamień nature reserve – the most important place for the Apollo butterfly in the Polish Sudetes
Kruczy Kamień is an inanimate nature reserve. It was established in 1954 and currently has an area of 12.61 ha. It covers western and south-western slopes of Krucza Skała (681 m above sea level) located in the Krucza Valley, in the Stone Mountains. The subject of the reserve’s protection is an interesting form of trachyte intrusion (a variety of porphyry of volcanic origin) in the sedimentary rocks of the Rotliegend. The area is made up of steep slopes with heights reaching 30 metres in places. Numerous rock formations occur here, and in many places extensive fields of rock rubble are formed as a result of the crumbling of the porphyry rock.
Most of the reserve is covered with artificially planted spruce forest. The reminder is covered mainly by rocky, xerothermic, pioneer and meadow vegetation. Among the more important habitats recorded in the reserve are ecosystems of Pontic-Pannonian character, which form a mosaic with xerothermic and rocky grasslands. At the foot of the escarpment there are rare – Subcontinental Peri-Pannonian shrubby habitats Rhamno-Prunetea thickets with numerous patches of Cotoneaster integerrimus (one of the largest in the Sudetes) and herbaceous plants. The shrubs are also accompanied by Festuco-Stipion Pannonic grasslands, with Sedum species, important for the Apollo butterfly Parnassius apollo. Habitats of ephemeral character have developed on the rock rubble layer and in rock crevices. This is the thermophilic pioneer vegetation of the rock shelves of the Alysso-Sedion association classified as Sempervivetum soboliferi complex. This habitat type is rich in the succulent species Jovibarba sobolifera, Sedum acre, Sedum maximum and Sedum album (artificially introduced). The latter two species provide a food source for the caterpillars of the Apollo butterfly. These ecosystems undergo gradual succession, becoming overgrown with taller vegetation, mainly grasses and perennials and then shrubs and trees. At the foot of the reserve there are habitats rich in nectariferous plants: patches of xerothermic grassland and herbaceous vegetation, and further on, lush and dense meadow vegetation composed largely of Centaurea and Cirsium species.
Rare plant species, including those protected by law in Poland, include: the endemic morphological form of Viola porphyrea, Cotoneaster integerrimus, Festuca pallens, Lilium martagon, Digitalis grandiflora, Melampyrum sylvaticum, Antennaria dioica and Asplenium septentrionale.
A rich insect fauna, especially butterflies, was found in the reserve. However, the most important has always been the local subspecies of the Apollo butterfly Parnassius apollo silesianus, which occurs here. This butterfly became extinct at the beginning of the 20th century, and the Krucze Mountains area was one of the last places of its occurrence in Lower Silesia. The first successful attempt to reintroduce the species in the reserve was made as early as the 1990s, and the butterflies persisted in the site for more than 10 years. Reintroduction continued in the 21st century, when breeding began as part of a project by the Fundacja Ekorozwoju, the Karkonosze National Park and the Stołowe Mountains National Park, which now continues under the Apollo2020 project. The habitat itself has also been cared for. Unfortunately, years have passed since the last conservation measures in the reserve. The sunny slopes have again become overgrown with shrubs and tree undergrowth. The thermophilic habitats have been shaded and the landslides have started to lose their dynamic character.
This winter, Klub Przyrodników carried out conservation measures in the reserve that will help to preserve and, in places, restore its peculiar charm. An area of approximately 1.7 hectares was cleared of shrubs (with the exception of Cotoneaster integerrimus), as well as tree undergrowth, including some larger specimens, the seeds of which are spreading along the slopes of Krucze Kamień reinforcing the succession process. Our further aim is to maintain the effects of these activities and stop the regrowth of felled shrubs and trees by grazing goats.
In spring, Apollo caterpillars can be seen in the reserve, which have hatched from the eggs laid by butterflies last year, and every summer, the spectacle of philutically flying Apollo butterfly plays out before our eyes on the slopes of the reserve and in the meadow at its foot. Our dream is to establish a permanent population of the species in the reserve, which will only need our help to cut the bushes.
