Rośliny naczyniowe na starych, nieczynnych cmentarzach Wielkopolski. Tom 1. Analiza danych

The vascular flora of 2211 old cemeteries was studied on the basis of field research conducted in 2005–2020 in the Wielkopolska region (western Poland). The distribution of all plant taxa is presented on a grid of 468 ATPOL squares (10 km × 10 km each). In total, 100 410 items of floristic data were collected and about 3000 herbarium sheets were initially deposited in the POZ herbarium (Herbarium Uniwersytetu im. Adama Mickiewicza w Poznaniu).
The analysed flora of old cemeteries no longer used for burial comprises 1335 taxa. These belong to 119 families, with the Rosaceae being the best represented (188 species). The richest genera are Rosa (40) and Rubus (39), and species from these genera have a symbolic meaning.
Most of the recorded species are rare (frequency classes I, II, and III jointly: 1142 taxa, i.e. 85.6% of the total) or infrequent but widely distributed (class IV: 79 taxa, i.e. 5.9%), followed by frequent species (classes V and VI jointly: 93 taxa, i.e. 6.2%) and common ones (classes VII and VIII: 31 taxa, i.e. 2.3%). The most common taxa (class VIII) include both spontaneophytes, namely Veronica sublobata (1677 localities), Quercus robur (1513), Galium aparine (1437), Chelidonium majus (1408), Urtica dioica (1270), Sambucus nigra (1258), and anthropophytes: Syringa vulgaris (1835), Gagea pratensis (1554), Hedera helix (1364), Robinia pseudoacacia (1360), Ornithogalum umbellatum (1320), and Viola odorata (1215). Thus, despite its distinctness, the vascular flora of the old cemeteries confirms the general rule that rare and infrequent species are more numerous than common ones.
The dendroflora of the studied cemeteries is composed of 67 taxa of trees and 113 taxa of shrubs and subshrubs. Native tree species prevail and are represented mainly by Quercus robur (1513), Acer platanoides (999), Fraxinus excelsior (995), and Tilia cordata (914). Among shrubs and subshrubs, most of the species are alien, especially Syringa vulgaris (1835 localities), Hedera helix (1364), Vinca minor (1036), and Symphoricarpos albus (933).
Some of the recorded taxa are new to Poland, as they were not listed by Mirek et al. (2020), i.e. Allium odorum, Chionodoxa forbesii, Ch. lucillae, Ch. Sardensis, Ch. sardensis ‘Alba’, Ch. sardensis × Ch. forbesii, Crocus speciosus, Deutzia parviflora, Erigeron gallica ‘Plena’ × R. dumalis, R. glauca × R. canina, R. majalis ‘Foecundissima’, R. nitida, R. palustris, R. ‘Poznań’, R. rubiginosa × R. canina, R. rubiginosa × R. inodora, R. rubiginosa × palsutris, R. rugosa × R. duvarica, R. rugosa × R. majalis ‘Foecundissima’, R. rugotida, R. ×spaethiana, Spiraea douglasii, and Viola palmata. Others were new to Wielkopolska: Allium paradoxum and Pilosella obornyana.
In the flora of the studied cemeteries, the contributions of native and alien species are nearly equal (50.7% and 47.8%, respectively), while 1.7% are hybrids between native and alien species. In the group of apophytes most species are ergasiophytes (27.7%), kenophytes (11.5%), and archaeophytes (7.6%). Ephemerophytes are the least numerous (1%). The presence of ergasiophytes is mostly due to the much earlier cultivation of plants, mostly of those with a symbolic meaning (culA), but also recent planting (culB) of mostly ornamental plants. Old cemeteries were subjected to human impact mostly during the period when they were used for burial, but some of them are still affected, primarily those transformed into parks (which are intermediate between the abandoned and currently used cemeteries). These include the Cemetery of the Meritorious on St Adalbert Hill in Poznań and military cemeteries on the slopes of Poznań Citadel. The list of ergasiophytes may change gradually because of the continuous enrichment of horticultural catalogues with new plant taxa.
The vegetation of the studied cemeteries represents six syngenetic groups of plant communities. However, most of the recorded plant taxa (461) are in group 16, i.e. they are not characteristic of any plant community because many of them are aliens introduced in the past (culA) or recently (culB). In the analysed flora, the best-represented groups are plants typical of communities of fertile deciduous forests, shrub communities, and forest edge communities (138 taxa), as well as open oak forests and xerothermic grasslands (132), but also acid oak forests, mixed coniferous forests, their substitute communities in logged plots, meadows, and dry grasslands (114). These three groups jointly account for 30% of the total flora. Group 9 is the least represented, as it includes only Trifolium fragiferum, whereas the second least represented is group 15, i.e. epilithic communities (5).
Some taxa are good and common plant indicators of former cemeteries. These include the following in the herb layer: Hedera helix (1364 localities), Vinca minor (1036), Saponaria officinalis (1020), Scilla sibirica (489), Sedum spurium (460), Hemerocallis fulva (408), Aquilegia officinalis (296), Iris germanica (282), Myosotis sylvatica (220), Narcissus poëticus (184), Lilium bulbiferum (170), and Dianthus barbatus (71), while in the shrub layer Syringa vulgaris (1835), Symphoricarpos albus (933), Spiraea chamaedryfolia (365), Ligustrum vulgare (387), Philadelphus coronarius (143), Rosa gallica ‘Plena’ (133), R. ×francofourtana (101), Caragana arborescens (96), Sorbaria sorbifolia (90), Rosa majalis ‘Foecundissima’ (75), Lonicera periclymenum (40), and Rosa spinosissima (35).
Some kenophytes and ergasiophytes tend to escape from cemeteries to adjacent plant communities. Most species of this group spread to nearby wooded patches chiefly vegetatively: Syringa vulgaris (1835 localities), Symphoricarpos albus (933), Sedum spurium (460), Spiraea chamaedryfolia (365), Aquilegia vulgaris (296), Lilium bulbiferum (170), Sorbaria sorbifolia (90), Jovibarba sobolifera (77), Dianthus barbatus (71), Chionodoxa sardensis (11), Scillla bifolia (5), and Chionodoxa forbesii (3). Only Aquilegia vulgaris (296) and Mahonia aquifolium (278) were noted far away from cemeteries.
The results suggest that some species should be added to the list of kenophytes in Poland, e.g. Anthriscus cerefolium, Asparagus officinalis, Cannabis sativa, Chionodoxa forbesii, Ch. sardensis, Hedera helix, Saponaria officinalis, Scilla sibirica, Silene armeria, and Vinca minor. In the Wielkopolska region, the last two mentioned taxa are usually found on anthropogenic sites. Hedera helix, if found in forests, is linked with the herb layer, so it does not flower. In contrast, flowering specimens were nearly always observed in old cemeteries. Supposedly, it is dispersed to deciduous forests by birds.
Among Raunkiaer plant life-forms, hemicryptophytes prevail (501), followed by nanophanerophytes (239 taxa), annual therophytes (226), megaphanerophytes (129), and geophytes (127). Geophytes include mainly spring species introduced in the past (culA) or recently (culB), because after long winters people waited for the first colourful plants. Group 9 is the least represented, as it includes only Trifolium fragiferum, whereas the second least frequent is group 15, i.e. epilithic communities (5).
Considering site fertility, the best-represented were mesohemerobic sites (1144 taxa) and euhemerobic ones (427). In contrast, 232 taxa were recorded on oligohemerobic sites and only 5 on polyhemerobic ones.
The analysed flora includes 48 plant species protected by law (20 strictly and 28 partly protected). Moreover, 121 of the recorded vascular plant species are classified as rare or threatened in Poland, thus they account for nearly 9% of the total flora.
Studies of the vascular flora of old cemeteries no longer in use are of great importance for advancing chorological research in Poland and for practical reasons, such as planning how they are managed. Thus, further studies are required in other regions. This applies especially to the cemeteries where the renovation of tombstones and sculptures is planned.