Biodiversity at the species and individual levels is one of the fundamental elements characterizing an ecosystem. It is assumed that the greater the level of biodiversity, the more tolerant the environment is to changes in external conditions. In recent years, dynamic climate change has negatively impacted the health of many forest trees across Europe, in particular Scots pine. Tree health is commonly characterized by crown defoliation. The study presented here describes and correlates crown defoliation with biodiversity indicators at the species and individual tree levels. Research was conducted in two national parks in Poland (Kampinoski and Bory Tucholskie). Since stands have been under legal protection for many years and forest management is not practiced there, stand development processes taking place there are similar to natural ones. This study provided empirical data on ecosystem response to external stresses based on species and genetic structure. The results confirm differing health of the populations, which results from, among other factors, stand age and the environmental conditions in which they grow. Pine stands in both national parks are genetically diverse but with low genetic variability. Differences in stand health are related to the number of alleles forming the genetic pool. This conclusion is supported by a high correlation coefficient for interactions between defoliation, the number of alleles, and the Shannon index for genotypes. This suggests that greater gene diversity is likely to provide a wider range of phenotypic responses to environmental change.

W pracy przedstawiono nowe stanowiska 25 rzadkich (lub regionalnie rzadkich) roślin naczyniowych w Polsce, tj. Allium angulosum, Asclepias syriaca, Bromus sterilis, Carex davalliana, Claytonia perfoliata, Dactylorhiza incarnata subsp. incarnata, Erechtites hieraciifolius, Euthamia graminifolia (Solidago graminifolia), Festuca myuros (Vulpia myuros), Gentiana cruciata, Gentiana pneumonanthe, Gypsophila paniculata, Lithospermum officinale, Najas marina, Pilosella aurantiaca (Hieracium aurantiacum), Pistia stratiotes, Scutellaria altissima, Senecio inaequidens, Silene coronaria (Lychnis coronaria), Stachys annua, Stellaria pallida, Typha shuttleworthii, Valeriana locusta (Valerianella locusta), Xanthium orientale (Xanthium albinum) oraz Zannichellia palustris.

Pulsatilla × hackelii Pohl. is the most common hybrid between Pulsatilla patens and Pulsatilla pratensis. It occurs in the natural environment, most often in sites together with parental forms. Pulsatilla × hackelii is morphologically intermediate between the pure Pulsatilla species. Separation of hybrid individuals from pure Pulsatilla species requires a whole set of morphological features. Completed plastid genome provides molecular evidence for the hybrid origin of Pulsatilla × hackelii. In our study, we present the—genotypic characteristics of Pulsatilla × hackelii based on microsatellite markers developed for Pulsatilla vulgaris. A specimen of the hybrid was found in the Świętokrzyskie Mountains, near Bocheniec village, in the vicinity of a forest road in a fresh mixed coniferous forest (Querco roboris-Pinetum (W. Mat. 1981) J. Mat. 1988). We amplified a set of 10 microsatellites in two multiplex PCR reactions. From the 10 analyzed loci, we successfully amplified eight. The analyzed microsatellites in population studies of three Pulsatilla species showed some species-specific alleles. In the case of the Pulsatilla × hackelii sample, we obtained PCR products in the case of 5 loci developed for P. vulgaris but successfully crossamplified in P. patens and P. pratensis. Additionally, we obtained results for two loci, which crossamplified only for Pulsatilla patens and one only for Pulsatilla pratensis. Among the investigated markers, two were monomorphic and the remaining six were polymorphic, which makes them highly informative in population studies for pasque-flower species as Pulsatilla patens, P. pratensis, and P. vernalis. The obtained results indicated that analyzed microsatellite markers could be used for hybrids identification, although there is a need for further research on a larger number of hybridized individuals.

Impatiens parviflora DC. occurs in various plant communities. Its occurrence has been confirmed in Poland across 13 natural habitats protected under the Habitats Directive. The aim of our work is to determine the differences between the plots with and without I. parviflora in terms of the species richness and ecological conditions of the 9180* habitat-type forest. Using data from 315 plots on which a phytosociological relevés was carried out, we analyzed the geographical variability, the Shannon-Winner index and the indicator species for old forests. Flora diversity was represented using the DCA, and the IndVal index was calculated to determine the species that best characterize the differentiated groups. The highest percentage of monitoring plots with I. parviflora is located in the Sudetes Mountains (67.7%) and the lowest in the Bieszczady Mountains (7.5%). Plots with I. parviflora were characterized by significantly lower tree cover, a higher number of tree species in the stand, a lower height of both the understory and herb layer and a lower number of old forest species. Impatiens parviflora does not affect the total number of species in the understorey but is associated with a lower proportion of species typical of old forests. The presence of I. parviflora also correlates with a higher proportion of young trees in the understorey, suggesting a link with successional processes and habitat disturbance. The spread of I. parviflora is limited by shade-loving trees such as Abies alba Mill. and Fagus sylvatica L. The diversity of the distribution of I. parviflora depends on local conditions, so conservation efforts should take into account the local ecological context.

Antipredator responses of prey are important because of their potential trophic cascade effects. Predator responses are especially important for species that impact the economy, such as ungulates. Past research has focused on the behavioral adaptation of roe deer, the most common ungulate in Europe, to human and lynx pressure. However, the European wolf population has increased in the last decade and in some recently recolonized parts of Poland roe deer constitute the largest food source for wolves. Unlike in moose and red deer, no evidence has yet been found for changes in the vigilance-foraging time ratio in roe deer in response to wolves. We took the unique opportunity to study the behavior of roe deer during the partial recolonization by wolves of a large forest complex (Tuchola Forest) in Poland. Using video cameras, we found that roe deer react differently to the presence of wolves compared with humans. Wolf predation increases roe deer movement. In comparison, anthropopressure causes roe deer to mainly use an avoidance strategy, limiting their activity to times of day when people are not present. This temporal avoidance strategy was similar whether human pressure resulted from recreation or hunting.