Prunus serotinaEhrh. is an alien invasive neophyte widespread in European forests. So far, no effective methods of its elimination have been developed. For this reason, the aim of our study was to determine how herbicides affect the morphological characteristics of pollen grains. This knowledge may be crucial to control this invasive species. The current study was carried out in a research area of 2.7 ha located in the Zielonka Forest near Poznań, Poland (N 52°31′58.016″, E 17°05′55.588″). We tested morphological differences among ten features ofP. serotinapollen, based on the samples collected from 15 control trees compared to the 50 trees treated with five different herbicides. In total 1950 pollen grains were measured. We confirmed the adopted hypotheses of long-term herbicide influence onP. serotinapollen. Pollen grains from the control trees had a longer equatorial axis, were more elongated in shape and had the largest range of exine thickness compared to the pollen from the herbicide-treated samples. Exine thickness in the control sample was on average 0.74 µm, ranging from 0.42 to 1.19 µm. The average values and the ranges of this trait in the samples treated with herbicides were larger (e.g. average exine thickness was from 0.90 to 0.95 µm). There were differences in the P/E ranges of variability between the control and herbicide-treated samples. In the control sample the P/E ratio was 1.32–2.04 and elongated forms of pollen shapes prevailed, while in the herbicide-treated samples it ranged from 1.03 to 1.47. The share of deformed pollen grains in the herbicide-treated samples was lower than expected, ranging from 8.7 to 25.3%, while in the control samples it was 6%. Logo and Mustang turned out to be the most effective among the herbicides used in the described research. The two used application methods were found to have an effect on pollen quality.

The pollen morphology was studied of 24 Salix species native to Poland, which represented two subgenera, 17 sections and five subsections occurring in Poland. The aim of this study was to discover the taxonomical usefulness of the pollen features under analysis, and to investigate the ranges of their interspecific variability. In total, 720 pollen grains were studied. They were analysed with respect to seven quantitative features (length of the polar axis ˗ P, equatorial diameter ˗ E, length of the ectoaperture ˗ Le, exine thickness ˗ Ex, and P/E, Ex/P and Le/P ratios) and the following qualitative ones: pollen outline and exine ornamentation. The most important features were exine ornamentation (muri, lumina and margo) characters. The pollen features should be treated as auxiliary because they allowed to distinguish eight individual Salix species, and five groups of species. Statistical analysis of the studied traits indicated a high variability among the tested species. The most variable biometric features were P, E and Le, while lower variability occurred in P/E, Le/P and d/E.

The North American Prunus serotina Ehrh. is an invasive neophyte widespread in Polish forests. Due to the negative impact of this species on native vegetation, the most effective methods of its removal from the stands have been searched for. Our research aimed to determine whether herbicides that were applied in spring 2020 influenced morphological features of inflorescences and flowers of P. serotina in the next year of vegetation (i.e., 2021). So far, the effects of herbicides used were analysed in the same year, no later than a few weeks after their application. The experiment was carried out on the research area of 2.7 ha located in the Zielonka Forest near Poznań in Poland (N 52.5330, E 17.1015). The response of 39 P. serotina trees to six different herbicides, containing sulfonylurea derivatives, glyphosate and phenoxy herbicides was investigated. The chemicals were applied directly to the tree, to the holes made in the trunk axis. The plant material included inflorescences from 10 control trees and 29 trees treated with different herbicides. Nine morphological inflorescence and flower features and three ratios were analysed. In total 200 inflorescences and 1000 flowers were measured. Statistically significant differences between inflorescence and flower features collected from trees treated with different herbicides were demonstrated. The largest ranges of values of the studied features were found in inflorescences and flowers collected from the control trees (C-WI, C-DWH). The greatest variability of the studied features was found for C-DWH. Compared to the control trees the reduction in inflorescence size, as well as the smaller number of flowers, were recorded in the trees treated with different herbicides, irrespective of an active substance content. The use of six different herbicides—with different active substance contents to control P. serotina proves to be effective.

The pressure of human activity in river valley environments has always been high. Even today, despite the increasing awareness of societies around the world regarding the need to protect water and biodiversity, there are concerns that the current river valley management systems are insufficient. Therefore, the aim of this study was to assess the state of knowledge about the soils and forest ecosystems of river valleys in terms of the possibility of protecting river valley environments. This study used data obtained from the Forest Data Bank (FDB) database, which focuses on forests in Poland. After analyzing 17,820 forest sections where the soils were described as fluvisols, it was found that forest areas associated with fluvisols (typical, fertile soils of river valleys) are quite well recognized and protected in Poland. Most (55%) forested fluvisols are located in Natura 2000 sites (an important European network of biodiversity hotspots), 4% in nature reserves, and 1% in national parks. Additionally, the main forest habitat type associated with fluvisols is riparian forest, composed mainly of Quercus, Ulmus, and Fraxinus, which is protected as Natura 2000 habitat type 91F0. Preserving the sustainability of the forest is also a form of soil protection. Despite the identification of soils and forests in river valleys, as well as appropriate legal tools, their protection may be ineffective due to the fragmentation of forms of protection and the lack of a coherent system for managing river valleys. Because the conservation status of the river valleys is also influenced by the management of areas located outside the river valleys, in order to protect river valley ecosystems, integrated conservation plans for entire catchments should be implemented. Due to potential conflicts related to the management of areas with diverse expectations of local communities, it would be advisable for such plans to be created by local experts but under the supervision of a specialist/specialists from outside the area covered by a given river basin.

Nowadays, the public needs to be made more aware of the benefits of sustainability for the local environment. It appears that tourism is a particularly effective tool for teaching sustainability and responsibility because it not only provides new experiences but also explains and enhances the visited area. Visitors should become more conscious of the need to preserve the ecosystem as a result of this remarkable experience, which is caused by skillfully planned activities. The authors of this study discuss the effects of tourism in the natural enclave of Poznań (Poland) while presenting the findings of interdisciplinary studies on locally threatened orchid species. The number and condition of individual orchids have not changed significantly as a result of rather strong anthropopressure, according to observations made since 1997. The study area is an ideal place to enhance environmental education and responsible tourism because it is also rich in historical values. Such tourism can be considered responsible urban tourism. According to the questionnaire study, which was based on 1000 surveys, respondents expressed a developing emotional attachment to the area and commended the educational pathways and changes in land use. They also acknowledged that they did not know enough about the location, the environment, or the cultural legacy. The current study demonstrates that, while society has grown to value the Kopanina wilderness, it has also begun to consider nature conservation from a wider perspective.