The protected flora of long-established cemeteries in Hungary: Using historical maps in biodiversity conservation

Assessing the conservation value of cemeteries to urban biota worldwide

Cemeteries are key urban green spaces with multifaceted societal and ecological importance. Their biodiversity is shaped by unique environmental and cultural factors. They can potentially protect rare and endangered species, yet their conservation value compared with other urban green spaces remains largely unexplored. We sought to fill this gap by systematically reviewing literature to investigate the conservation value of cemeteries relative to other urban green spaces (botanical gardens, institutional premises, natural remnants, and parks) by comparing species richness and proportions of native and unique species. We analyzed data from 70 papers covering 50 cities in 27 countries with linear and binomial mixed-effects models at both site and city level. Cemetery conservation value was similar to urban parks, except for the proportion of unique species, for which parks had significantly higher proportions (21.9% vs. 14.2%, p < 0.001). Cemeteries hosted slightly higher proportions of native species at the city level than botanical gardens (99.7% vs. 99.6%, p < 0.001) and institutional green spaces (96.3% vs. 94.1%, p = 0.034) and proportions comparable to parks and natural remnants (p > 0.05). They also had similar or higher values than institutional premises in species richness and unique species proportions (p > 0.05) and a higher site-level proportion of native species (p < 0.001). In contrast, species richness (slopes = -0.11 and -0.25, respectively) and unique species proportions (4.4% and 6.9%, respectively, p < 0.001 for both) were lower in cemeteries than in remnants of natural areas and in botanical gardens. The conservation value of cemeteries and parks was similar for animals, but parks had a higher value for plants. Overall, cemeteries were generally at least as valuable as some other green spaces for urban biodiversity and mostly native biota. Their religious and cultural significance suggests they will remain intact in the long term; thus, it is essential to prioritize and further promote their biodiversity in conservation and sustainable urban design plans.

Orchids of Azerbaijani Cemeteries

In order to explore their orchid flora, we performed surveys of 96 Azerbaijani burial places in 2018 and 2019. Altogether, 28 orchid taxa were found in 37 visited cemeteries. In the orchid diversity a remarkable pattern was observed: geographic latitude was significantly and positively related to the number of taxa and number of individuals. The most widespread and abundant orchids in Azerbaijani graveyards were Anacamptis pyramidalis and A. papilionacea (found in 23 and 8 cemeteries, respectively). Azerbaijani cemeteries can be important refuges for rare and threatened orchids, e.g., Himantoglossum formosum (three cemeteries), Ophrys sphegodes subsp. mammosa (eight), Orchis adenocheila (two), O. punctulata (three), O. stevenii (one) and Steveniella satyrioides (one). Epipactis turcica, detected in a single locality, was previously unknown to the flora of Azerbaijan. Additionally, we documented orchid tuber (salep) collection in two cemeteries.

To Care or Not to Care? Which Factors Influence the Distribution of Early-Flowering Geophytes at the Vienna Central Cemetery (Austria)

Cemeteries not only serve as burial sites but also as a habitat for many animal and plant species, as the specific management of cemeteries creates conditions that hardly exist anywhere else. So-called stinzen plants are those plant species that show a connection to old garden cultures and need precisely these conditions. Many stinzen plants are early-flowering geophytes. We examined which factors influence the distribution and abundance (=cover values) of early-flowering geophytes at the largest cemetery in Austria, the Zentralfriedhof in Vienna, and tried to identify such stinzen populations. In spring 2020, we performed two vegetation surveys in 143 plots and recorded the occurrence and abundance (in %) of early-flowering geophytes. Then, we collected four variables for each plot: (1) cemetery type (architectural cemetery, park cemetery, and memorial), (2) care intensity, (3) type of use (path between graves, abandoned graves, free space between road and grave, and open meadow area with adjacent graves), and (4) distance to the next path. We recorded a total of nine different early-flowering geophyte species. All nine species were found on plots with very low care intensity. Only two species were found on paths between graves. Six species are listed as threatened on Vienna’s Red Data List. Two species, Eranthis hyemalis and Galanthus nivalis, are ornamental plants. Plots in the park cemetery have significantly lower average cover values of early-flowering geophytes than plots in the other two cemetery types. This can be explained by high maintenance measures and increased visitor pressure due to its location. Additionally, the data revealed that high care intensity seems to harm early-flowering geophytes. This study showed that cemeteries are refugia for protected species in urban areas and should, therefore, be considered in urban nature conservations.

Linking environmental heterogeneity and plant diversity: The ecological role of small natural features in homogeneous landscapes

Small natural features (SNFs), such as road verges, midfield islets, rocky outcrops and ancient burial mounds, provide safe havens for species of natural habitats in human-modified landscapes; therefore, their great ecological importance is in contrast to their small size. SNFs often have a high topographical heterogeneity and abiotic conditions, which differ from their surroundings; therefore, they provide a unique opportunity for establishing links between environmental heterogeneity (EH) and biodiversity. However, no study has so far investigated the EH components of topographically heterogeneous SNFs in a comprehensive framework, by linking environmental and biotic parameters. To fill this knowledge gap, we evaluated the EH components and their effect on biodiversity on ancient mounds covered by semi-natural grasslands in the Pannonian (Hungary) and Continental (Bulgaria) biogeographical regions. We designated 16 study sites, each containing a few-metre-high mounds with five microsites (top, north-, east-, south- and west-facing slopes) and a nearby plain grassland. At each microsite, we measured soil moisture, soil chemical properties, solar radiation and microclimate; and recorded the cover of vascular plants in a total of 480 plots. On the mounds, topographical heterogeneity was associated with sharp differences in microclimate and soil properties. Besides the contrast between mild north-facing and harsh south-facing slopes, east- and west-facing slopes also sustained unique microsites characterised by dynamic diurnal changes in air temperature and vapour pressure deficit. Various combinations of the EH components resulted in unique plant species compositions within the microsites, and supported the co-occurrence of species typical of contrasting habitat types, even within a couple of metres. By combining high-resolution measurements of abiotic factors with fine-scale vegetation sampling, our study provides evidence that widespread SNFs with complex topography harbour several grassland-specialist plant species and introduce a high level of EH to otherwise homogeneous plain landscapes, which cover one third of the global land area.