The turn of October and November is always saturated with the atmosphere of Halloween or All Saints' Day. So why not come up with a bit of a ghost article? Whether American or Czech tradition, both are in a way tied to the cemetery environment. This article is about the cemetery, or rather what and where it grows there.
Each of us must have noticed at one time that there are tombstones, but also other surfaces covered with lichens. They have innumerable species, differing in symbiotic relationships with fungi and algae, their body or preferred substrate. Their diversity, attachment to various surfaces and the influence of the environment on growth were investigated by a team of scientists from the Faculty of Forestry and Wood Sciences in cemeteries in Eastern Bohemia.
For a total of 65 species of lichens, the researchers determined the pH requirements of the substrate (acidic, nitrogenous, calcareous or neutral environment), whether they fall into the category of stone, tree bark or soil-dwellers, what is their status in the Red List of Endangered Species and what type of substrate they prefer.
These records show that lichens have a higher species diversity in urban cemeteries than in rural cemeteries. The majority (61.5%) grew on a stony surface, with sandstone being the most preferred substrate. If lichens grew on trees, then they were mostly deciduous tree species. In 44.6% of cases, lichens preferred acidic substrates. The most common species was Lecanora dispersa, growing on concrete or granite. Amandinea punctata had the highest record in the trees.
Although there were fewer lichens on the trees, it is clear that woody plants contribute to the species diversity of lichens. Cemeteries are specific for their park planting with alleys or solitary trees and it is necessary to constantly support it and take care of the woody plants. Lichens are important fighters with dust in the air and also noise due to the absorption of pollutants, and since they do not find suitable substrates in built-up localities, cemeteries are one of the few refuges for them.
When you go to the grave to light a candle, look around and notice how many lichens of diverse colour and shape grow there. You will surely be surprised at how many differences you find between them.
Josef P. Halda, Vladimir Janecek, Jakub Horak. Important part of urban biodiversity: Lichens in cemeteries are influenced by the settlement hierarchy and substrate quality, Urban Forestry & Urban Greening, Volume 53, 2020, 126742, ISSN 1618-8667.
Ing. Vladimir Janecek, Ph.D.
Dr. Janeček is a teacher at the Department of Forest Ecology. He is a popular teacher among students because he brings much more to class than just the subject matter itself. As part of his scientific work, he focused on the inconspicuous endangered bog orchid or agroforestry in urban environments.
Prepared by Lucie Hambálková