Malacofauna of Bolków castle (Lower Silesia, SW Poland) – trends and perspectives

Bolków castle is located in the Lower Silesian voivodeship near the Kaczawskie Mountains. Malacological studies were carried out in 2006, 2010 and 2021. In 2006, specimens were collected only by hand, but in 2010 and 2021 samples were also made by litter sieving and from material taken from rock shelves and walls. Overall, 35 species were found, but the numbers declined over time: 28 species in 2006, 26 in 2010 and 20 in 2021. Two species recorded before our studies were not found again. Abundance declined greatly between 2010 and 2021. Over this period, open-country species declined the most, and shade-loving species increased as a proportion of the whole. In particular, the open-country Pupilla muscorum, eudominant in 2010, was absent in 2021, while the tolerant Alinda biplicata increased greatly over the same period. While more widespread environmental or climatic change may be involved, the castle has been subject to increased human pressure and a renovation programme in 2015. Castle faunas, here and elsewhere, are not only refugia for locally or nationally uncommon species, but provide a basis for regular monitoring of faunal change. Other castles in the region, most especially those at Stary Książ and Książ have similar faunas, and can be used in the same way.