Important part of urban biodiversity: Lichens in cemeteries are influenced by the settlement hierarchy and substrate quality

Abstract

Cities, towns and villages are important places with almost specific greening in comparison with open landscapes. Cemeteries are one of the most common land-use types in Central European settlements; however, they are still rather marginal regarding their total extent. In this study, we focused on the diversity of lichens in these important artificial habitats.Our study was done in the Czech Republic and we analyzed 164 substrates (trees and gravestones) in 19 cemeteries located in a city, a town and in villages between them.Our results reveal that the majority of 65 species of lichens were rock-dwellers, preferring silicate substrates. Notably, ten species were red-listed. We found greater species richness in the town cemeteries, followed by village cemeteries, with those in the city most species-poor. Gravestones hosted a significantly higher number of lichen species than did trees. For tree-associated species, broadleaf species supported greater lichen species richness than did conifers. For rock-dwelling species, sandstone gravestones supported greatest lichen species richness, while those of concrete hosted the fewest species.The results of this study indicate that cemeteries are important habitats for lichen diversity in human settlements. Cemeteries hosted a diverse community of lichens, including a number of threatened species. Even though trees were not as species rich as gravestones, they did support a different community of lichens in these cemeteries, suggesting that trees, particularly broadleaf species, provide important habitat in cemeteries to support a diverse lichen community. Planting of broadleaf trees and especially the retention and management of existing trees appears to be one of the most important management considerations for cemeteries to support diverse lichen communities.