Contribution to the knowledge of fungi of the Kampinos National Park (Poland) with particular emphasis on the species occurring in burnt places

Spruce-dominated forests are commonly exposed to disturbances associated with mass occurrences of bark beetles. The dieback of trees triggers many physical and chemical processes in the ecosystem resulting in rapid changes in the vegetation of the lower forest layers. We aimed to determine the response of non-tree understory vegetation to the mass dieback of Norway spruce (Picea abies) in the first years after the disturbance caused by the European spruce bark beetle (Ips typographus) outbreak. Our study area was the Białowieża Biosphere Reserve covering the Polish part of the emblematic Białowieża Forest, in total 597 km². The main data source comprised 3900 phytosociological relevés (combined spring and summer campaigns) collected from 1300 systematically distributed forest sites in 2016–2018 – the peak years of the bark beetle outbreak. We found that the understory responded immediately to mass spruce dieback, with the most pronounced changes observed in the year of the disturbance and the subsequent year. Shade-tolerant forest species declined in the initial years following the mass spruce dieback, while hemicryptophytes, therophytes, light-demanding species associated with non-forest semi-natural communities, as well as water-demanding forest species, expanded. Oxalis acetosella, the most common understory species in the Białowieża Forest, showed a distinct fluctuation pattern, with strong short-term expansion right after spruce dieback, followed by a gradual decline over the next 3–4 years to a cover level 5 percentage points lower than before the disturbance. Thus, our study revealed that mass spruce dieback selectively affects individual herb species, and their responses can be directional and non-directional (fluctuation). Furthermore, we demonstrated that the mass dieback of spruce temporarily increases plant species diversity (α-diversity).

Landslides and erosion processes cause a high level of morphological diversity which, over the course of time, results in an increased level of forest species and habitat biodiversity. According to the principles of landscape ecology, information concerning points of convergence—understood as transition zones between elementary parts of a slope—could be interpreted as a surrogate for biodiversity. To recognize locations of land surface disruption, points of convergence derived from a high-resolution digital elevation model (DEM) were used in the research. It was assumed that relationships exist between landslide geodiversity and biodiversity and that from the DEM it is possible to select bare-earth surface structures where points of convergence can be identified. In order to verify this hypothesis, indicators of biodiversity such as richness of plant species and species diversity were checked. Based on the spatial distribution of points of convergence, locations of sample plots were planned and these indicators were verified during fieldwork. Samples were taken both in areas with a high concentration of points of convergence and in areas with a low concentration (or absence) of points of convergence. The results show that species diversity in the areas having a high concentration of points of convergence was significantly higher than in the areas having a low concentration of points of convergence. The proposed method allows the selection of parts of forested landslides that have the potential to develop a high level of biological diversity; it thus supports the management of areas of forest ecosystems with high levels of biodiversity within the scope of a cutting system. This may entail avoiding the traversal of areas that potentially possess high biological diversity with skid roads, preserving parts of these areas with thick vegetation for forest game purposes or leaving predominant and dead trees. The proposed method may also be used in scientific research into processes of biodiversity appearing on forested landslides.

Traditionally managed patch of Cladonia-Scots pine forest in the Biebrza valley – specifity of the protected forest community shaped by human activity

The experiment conducted in the Kampinos National Park since 2015 is aimed at investigating the relationship between the dynamics of black cherry sprouting response and the type and term of implementation of the mechanical elimination procedure. It also identifies macrofungi colonizing trees undergoing eradication. Three treatments, basal cut-stump, cutting (height: ca. 1 m) and girdling, were performed on 4 terms: early and late spring, summer and winter. Each variant was conducted within two plots, and applied to 25 trees, to 600 trees in total. For two consecutive vegetation seasons, sprouts were removed approximately every 8 weeks with the exception of winter-treated trees. Qualitative data were analysed, that is, the number of trees with and without sprouts at subsequent controls, and at the end of the second season, except winter-treated trees. Initially, almost 100% of the trees cut at the base and cut high responded by sprouting. The share of trees without sprouts gradually increased during the following vegetation season, from 3 ^rd to 5 ^th repetition of the sprouts removal, depending on the variant of experiment. Girdling contributed to a delay in sprouting. The effectiveness of procedures, expressed as share of trees without sprouts at the end of the second vegetation season, ranged widely (12%–84%), and depended statistically significantly on the date of the treatment. The effectiveness was higher for treatments done in early (average 68%) and late spring (average 74%), as compared to those done in summer (average 35%). Mycological research concerned 600 trees, including those treated in winter, without sprouts removal. Occurrence of 26 taxa of macrofungi was confirmed on 25% of trees; most of them having wood-decaying properties. Chondrostereum purpureum was most frequent, colonizing 9% of trees. Impact of plots varying soil moisture on succession and rate of fungi colonization, and on sprouting response dynamics requires further research.