Macromycetes of the Palace Park in Poznań-Radojewo (Wielkopolska Region, Poland)

This work aimed to present the diversity of fungal species in the PoznańRadojewo park. It was characterized based on literature data, unpublished master’s theses, the authors’ data, as well as data collected during two mycological trips organized by the Mycological Section of the Polish Botanical Society. Between 1980 and 2017, as many as 333 species of macromycetes have been found within the park in Poznań-Radojewo (among them 19% are rare and endangered), including eight protected species (Mitrophora semilibera, Morchella esculenta (var. esculenta and var. umbrina), Geastrum corollinum, G. fornicatum, Hericium coralloides, and Myriostoma coliforme), as well as two species new to the Polish mycobiota: Psathyrella bipellis and P. larga. The park in Poznań-Radojewo is very important for maintaining a high species diversity of fungi within the city of Poznań. During revitalization works, it is of paramount importance to take the needs of rare, threatened, and protected species under consideration and to preserve the natural character of plant communities. It is also vital to ensure the presence of coarse woody debris at different decomposition phases, which serves as an important substratum type for rare fungi.

The park is included in the Natura 2000 Biedrusko PLH300001 area (Directive of the Regional Directorate for Environmental Protection in Poznań, 2013) and it is a listed object (reg. No. A407). At the beginning of the nineteenth century, a palace was built in the park, around which a landscape park with romantic elements was created (Łukasik & Targońska, 2010). The park is partly located on a high slope and its tree stand harmoniously merges into the forests, meadows, and fields in the Warta River valley. From the analysis of the nineteenth-century maps, we can infer that the park was created in a deforested area (Łukasik & Targońska, 2010). At present, according to Łukasik and Targońska (2010), there are 29 tree species in the park (only three coniferous ones), in which: Quercus robur L. (28.5%), Fraxinus excelsior L. (23.4%), Acer platanoides L. (14.1%), Robinia pseudoacacia L. (10.8%), and Tilia cordata Mill. (6.5%) have the largest share. Czarna et al. (2009) reported 16 species in the tree stand. Originally, trees such as Abies sp. and Picea sp. also grew there. The flora consists of 165 plant species, creating about 20 different plant communities (Czarna et al., 2009). There are riparian forests, Querco-ulmetum minoris violetosum odoratae, growing in the largest part of the park. In the southern part, there grows Galio sylvatici-Carpinetum, and the rest of the park is Chelidonio-Robinietum. The shrubs represent communities with lilacs, Syringa vulgaris, as well as Aegopodio sambucetum nigrae and Euonymo-Prunetum spinosae. Open spaces are meadows Arrhenatheretum elatioris (Czarna et al., 2009). It is currently planned to adapt the park for tourism using its natural values (Mikołajczak & Borowiak, 2013).
Mycosociological studies have been carried out in the park in Radojewo, and the results have either been published (Lisiewska & Ratyńska, 1984) or are unpublished in master's theses (Gabor, 1985;Jaśkowiak, 1999). Reports on single fungi species have been published from this area (Kujawa & Gierczyk, 2007, 2011a, 2011bZychla, 2007). In May and October 2017, there were two field trips by members of the Mycological Section, Polish Botanical Society (PBS) covering its monthly meetings. This work aims to show the diversity of fungi species within the Poznań-Radojewo park.
The fungal nomenclature follows that of Knudsen and Vesterholt (2012), and for other taxa -Index Fungorum (http://www.indexfungorum.org/). Threatened species categories have been listed according to the red list (Wojewoda & Ławrynowicz, 2006), and the protected species according to the regulation (Regulation of the Minister of Environment, 2014).
The list of species has been presented according to the following scheme: species [synonyms according to the checklists (Chmiel, 2006;Wojewoda, 2003), status, source of data (the name according to the quoted source)]. Short descriptions of macro-and microscopic features are provided for species new to Poland.

Discussion
There is high fungal diversity and species richness in the park in Poznań-Radojewo. A similar level of species diversity has only been noted from the Kórnik Arboretum -325 species (Lisiewska, 2004), the Gołuchów Arboretum -about 300 (Lisiewska & Płaczek, 1993), and the Przelewice Arboretum -300 (Friedrich, 2010). These objects are twice (Kórnik and Przelewice) or 8 times (Gołuchów) as large as the park in Poznań-Radojewo, and more floristically diverse.
Mycological studies in urban and rural parks provide important information on the possibility of the survival of fungi (including forest species) in habitats, which are strongly influenced by humans.
Nowadays, the biodiversity is in decline, these substitute habitats are very important for its conservation. It implies the urgent need for cooperation between conservation officers (if the park is a historical monument), landowners or park managers (in the case of the Poznań-Radojewo park -State Forests) with biologists (botanists, zoologists, mycologists) and landscape architects. This cooperation is crucial in the planning of cultivation activities and revitalization practices.
The park in Poznań-Radojewo is a very important site for maintaining a high level of fungal species diversity within the city of Poznań. During revitalization works it is of paramount importance to take the needs of rare, threatened, and protected species under consideration, and to preserve the natural character of plant communities. It is also vital to ensure the presence of coarse woody debris (Figure 7)