Buglossoporus quercinus is widely distributed across Europe, within the range of Quercus robur. Throughout the area, in which it appears, it is rare or very rare. B. quercinus is associated with large old oaks (Quercus, usually Q. robur), whose numbers are decreasing due to ongoing changes in the environment. It was added to the Red Lists of fungi in a number of countries, along with awaiting inclusion in the IUCN Red List. In this study we have critically analysed the existing data on the occurrence of B. quercinus in Poland. We have presented two new localities of the species in Poland, as well as new records in the Białowieża National Park, the only place, where this species had been previously recorded in Poland. Selected trees and logs inhabited by B. quercinus were characterized. We have indicated the number of observed basidiomata, their phenology, and the sizes of the largest specimens. We have identified eight fungal species (Bisporella citrina, Daedalea quercina, Hapalopilus croceus, Hymenochaete rubiginosa, Laetiporus sulphureus, Mycena galericulata, M. inclinata, Xylobolus frustulatus) that coexist with B. quercinus. Based on the new distribution data for B. quercinus in Poland, this species should be classified as Endangered (EN) according to the IUCN Red List criteria.

Keywords: wood-decay fungi, rare species, fungi protection, Red List, Central Europe, oak

   The health condition of European ash (Fraxinus excelsior) stands in Ukraine has become worse since 2006. Firstly, in 2011 an alien invasive pathogenic fungus Hymenoscyphus fraxineus was identified in the eastern part of the country and, subsequently, its presence was confirmed in the western and central parts. The aims of our research were to evaluate the health of ash trees and identify the main causes of ash decline in different regions of Ukraine with emphasis on ash dieback and its association with collar rots.

   Results showed that since 2013 the number of trees with ash dieback symptoms has been gradually increasing, reaching up to 92 % in 2018. Total mortality due to ash dieback was up to 9 % in 2018. Disease intensity remains high in northern and central Ukraine comparing with the east. Branch dieback, collar rots, epicormic shoots and bacterial disease of ash occurred more often in the eastern region, some symptoms were observed simultaneously. Ash bark beetle galleries, as well as foliage browsing insects, were found mostly in weakened and/or dying trees.

   It was indicated that collar rots significantly increase the mortality of ash trees. Armillaria spp. fungi were found to be frequently associated with ash dieback on living stems and fallen trees in 2017, causing high rates of mortality in the northern and central regions. For further ash conservation and breeding programmes, resistant trees in severely damaged regions should be selected to preserve genetic diversity in ash populations.

Keywords: Fraxinus excelsior, ash dieback, collar rot, bacterial disease, epicormic shoots, Hymenoscyphus fraxineus, Armillaria spp.

   Seeds from seed orchards and seed stands may differ in morphology and quality, both determined during the seed assessment. The study aims at the comparison of phenotypic characters of cones and seeds originating from economic seed stands and seed orchards of Scots pine from western Poland. The study was conducted in 5 seed stands and 5 clonal seed orchards, representing five Scots pine populations. The analyses included the following measurements: length and width of cones, the number of empty and full seeds in the cone and the weight of 1,000 seeds. Moreover, the measurements of the length and width of the seed surface were carried out.

   The analysed seed stands and orchards were characterized by high variability in terms of the size and weight of cones and the amount of seeds. An ANOVA treatment showed that seed stands and orchards significantly differed in length and width of cones and seeds. Both seeds and cones from the seed orchards were characterized by higher values of analyzed traits than ones from the economic seed stands. Differences in mass of cones and 1000 seed weigh were of low significance (p = 0.022 ÷ 0.037). Significant differences between the length of seeds and seed area among all of the examined populations were demonstrated. The percentage contribution of empty seeds for all of the analysed sites of origin was not statistically significant.

Keywords: Scots pine, population, seed orchards, variation, seeds, cones

   The aim of this study was to define effects of cadmium (Cd) applied alone and in combination with citric acid, on the plant tolerance, accumulation, translocation and photosynthesis in willows (Salix viminalis, S. matsudana and S. alba). Low metal bioavailability in soil is often the limiting factor for phytoextraction, thus citric acid was used as a chelating agent aiming to improve metal solubility and therefore accelerates phytoextraction. Willows were grown by soil culture method in semi-controlled conditions (greenhouse) with two different Cd concentrations (3 and 6 ppm), applied separately and in combination with citric acid (20 mM/kg of dry soil), followed by control plants. The reduction of plant growth, biomass, photosynthesis parameters, chlorophyll and carotenoids were induced by Cd supplied. The addition of citric acid (CA) showed beneficial effects on different morpho-physiological levels through alleviate stress conditions as well as enhancing overall phytoextraction. Citric acid has increased transport of the accumulated Cd from the roots to aerial part in S. viminalis and S. alba in comparison with same treatments without CA, as well as tolerance of analyzed clones. Significant depressive effect on photosynthetic CO₂ assimilation was evident in plants grown in soil with Cd applied. A significant negative correlation between biomass production, leaf area, and photosynthesis due to the presence of Cd in plant tissue was observed in S. viminalis. Bioaccumulation factor among selected willow clones was higher than 1, reliably suggesting good potential of selected genotypes for phytoextraction.

Keywords: willows, cadmium, citric acid, soil phytoextraction, photosynthesis, accumulation, translocation, tolerance.