An analysis of fungi species in the arboretum Kostelec nad Černými lesy.
The arboretum Kostelec nad Černými lesy, which is today an integral part of the Faculty of Forestry and Environment, Czech University of Agriculture, Prague (Czech Republic), is an important dendrological collection holding more than a thousand taxons of predominantly non-native woody plants. A mycological survey was conducted in the late summer and autumn of 2004, throughout the year in 2005 and in the spring of 2006. The collection of fruiting bodies was undertaken at two-week interval with the aim of covering as large area as possible. Observations were predominantly focused on macromycetes; from micromycetes only pathogens of woody plants were collected and identified. Mycological data were sampled and analysed by standard methods. There were found 157 species of fungi on the area of the Arboretum. In respect of genera abundance the order Russulales was found to have the highest level of representation, followed by the order Polyporales from the libriform fungi. Some rare or sparsely occurring species were also found - Amanita rubescens var. annulosulphurea, Exidia truncata, Boletus subtomentosus, Hygrocybe mucronella, Macrolepiota excoriata, Russula delica, R. galochroa, R. gracillima, R. integra, Boletus rubellus and Suillus placidus. Among the pathogenic fungi an increased occurrence of foliar scald (Apiognomonia errabunda) and mildew (Microsphaera alphitoides) was recorded. Needle cast Lophodermuim pinastri and L. seditiosum on various species of Pinus were represented in the analysed samples by L. pinastri (60%), L. seditiosum (40%). Another needle cast Cyclaneusma minus was found on species Pinus jeffreyi, P. ponderosa and P. nigra, and Lophodermium juniperinum on various species of junipers. Genera Pestalotia was sporadically found on the bark of dying branches of Pinus sylvestris. Fruiting bodies of recently introduced Sphaeropsis sapinea were found in 2004 and 2005 on Pinus nigra and the three-needle Pinus spp. White pines (Pinus strobus) have been attacked for a long time now by white pine blister rust Cronartium ribicola. Even though the systematic monitoring of fungi occurrence was conducted only in 2005 (in 2004 late summer and autumn were included, in 2006 spring was included), the figure of 157 species is relatively large but not final. From the continuance of the survey we expect to find interesting and rarer taxons, and eventually new relationships between native pathogens and non-native woody plants.