Background and Objectives: Physical activity, recreation and walks successfully counteract negative symptoms of stress in people, especially in large cities, and have many positive psychological and physiological effects. There are many studies showing that contact with nature plays an important role in the regeneration of the human body. The city is not without green enclaves such as forests, parks or greenery along the streets. However, it is not entirely clear how the different physical characteristics of the urban space affect mood improvement, increase of positive feelings, vitality level, etc. Materials and Methods: In the study, two urban environments (apartment and green suburbs) were used, as well as two forests (coniferous and deciduous) to measure the impact of these environments on human physiological and psychological relaxation during a walk in a randomized experiment. The participants of the experiment were 75 young adult Poles studying in the largest Polish agglomeration, Warsaw. Before each experiment, the physiological and psychological state of the participant was measured indoors (pre-test). Four psychological questionnaires were used in the project (Profile of Mood States; Positive and Negative Affect Schedule; Restorative Outcome Scale; Subjective Vitality Scale), and physiological measurements (heart rate, blood pressure) before and after the short walking program were evaluated. Results: As a result of the analyses, it was shown that both staying in an urban environment with greenery and staying in a forest environment have a positive effect on the physiological and psychological relaxation of the subjects. A short walk in the suburbs was no less attractive than a walk in the forest in fall. The above indicates that various places with urban vegetation can be successfully used for recreation, just as in a forest where forest bathing is practiced. This indicates that different places with urban greenery can be successfully used for recreation, as can the forests where forest bathing is carried out.

The positive effect of forest bathing on the mental health and wellbeing of those suffering from post-traumatic stress disorder or experiencing stress has been proven. It is not known, however, how ‘forest therapy’ affects the mental health of people who are treated in a psychiatric hospital for affective or psychotic disorders. Potentially, forest therapy could bring many benefits to these people. To test the potential effectiveness of this therapy, a quasi-experiment was carried out in a psychiatric hospital in Olsztyn (north Poland). In the summer and autumn of 2018, the patients of the psychiatric hospital in Olsztyn participated in forest therapy interventions. The proposed forest therapy consisted of participating in one hour and forty-five minutes walks under the supervision of a therapist. Subjects filled out the Profile of Mood States Questionnaire (POMS) and the State Trait Anxiety Inventory (STAI-S) before and after the study. In the case of a group of patients with affective disorders, forest therapy had a positive effect on nearly all POMS scale subscales, with the exception of the ‘anger–hostility’ subscale, which did not change its values significantly after the intervention. In these patients, the greatest impacts were noted in the subscales ‘confusion’ and ‘depression–dejection’; the level of anxiety measured with the STAI-S scale also significantly decreased. In the case of patients with psychotic disorders, the values of the ‘confusion’ and ‘vigour’ subscales and the STAI-S scale exhibited the greatest changes. These changes were positive for the health of patients. Regarding the ‘fatigue’ subscale, no significant changes were observed in patients with psychotic disorders. The observed changes in psychological indicators in psychiatric hospital patients with both kinds of disorders indicate that the intervention of forest therapy can positively affect their mental health. The changes observed in psychological indicators were related to the characteristics of the given disorder.

Forest recreation is an activity that could be successfully used to alleviate negative symptoms of stress in individuals. Multiple positive psychological and physiological effects have been described in the literature, especially regarding works describing research from Asian countries such as Japan, Korea, and Taiwan. In East-Central Europe, however, the effectuality of forest recreation has not been addressed in scientific research. Thus, a special recreation program was developed, and its usability was examined with the involvement of 21 young Polish adults. A pre- and post-test design was used, wherein four psychological questionnaires were applied (Profile of Mood States, Positive and Negative Affect Schedule, Restorative Outcomes Scale, Subjective Vitality Scale), and physiological measures were assessed (pulse rate, blood pressure) before and after the program. A field study was also conducted at the nature reserve Redykajny, near the suburban forest of the city of Olsztyn. The recreational program had a significant impact on psychological and physiological parameters. After recreation, the negative mood markers of the negative affect decreased and the positive affect, including restoration and vitality, increased. Furthermore, pulse rates, systolic blood pressures, and mean arterial pressures of the participants were significantly lower after the program. These results reveal that the short forest recreation program may be effective in reducing negative symptoms of stress.

Trees in urban and industrial areas significantly help to limit the amount of particulate matter (PM) suspended in the air, but PM has a negative impact on their life. The amount of PM gathered on leaves depends on quantity, size, and morphology of leaves and can also be increased by the presence of epicuticular waxes, in which PM can become stuck or immersed. In this study, we determined the ability of PM to accumulate on leaves in relation to the species of tree and PM source. We tested saplings of three common European tree species (Betula pendula,Quercus robur, andTilia cordata) by experimentally polluting them with PM from different sources (cement, construction, and roadside PM), and then assessing the effects of PM on plant growth and ecophysiology. In all studied species, we have found two types of PM accumulation: a layer on the leaf surface and an in-wax layer. Results showed that the studied species accumulate PM on their leaf blade, reducing the efficiency of its photosynthetic apparatus, which in a broader sense can be considered a reduction in the plants’ normal functioning. Saplings ofQ. robursuffered the least, whereasB. pendula(especially photosynthetic rate and conductivity) andT. cordata(especially increase in leader shoot length) exhibited greater negative effects. The foliage ofB. pendulacollected the most PM, followed byQ. robur, and thenT. cordata, regardless of the dust’s source. All tested species showed a tendency for higher wax production when growing under PM pollution stress. We believe that, potentially,B. pendulabest enhances the quality of the PM-contaminated environment; however, faster leaf fall, reduced productivity, and worse quality of wood should be considered in urban forest management.

Forest recreation can be successfully conducted for the purpose of psychological relaxation, as has been proven in previous scientific studies. During the winter in many countries, when snow cover occurs frequently, forest recreation (walking, relaxation, photography, etc.) is common. Nevertheless, whether forest therapy conducted in a forest environment with a snow cover will also have a positive effect on psychological indicators remains unknown. Furthermore, male subjects frequently participate in forest therapy experiments, whereas females are rarely involved. Thus, in this study, the effectuality of forest recreation during winter and with snow cover was tested on 32 young females. For these reasons, the experiment involved 15 min periods of relaxation in a forest environment or in an urban street environment, in addition to a pre-test under indoor conditions (randomized controlled study). Four psychological questionnaires Profile of Mood States (POMS), Positive and Negative Affect Schedule (PANAS), Restorative Outcome Scale (ROS), Subjective Vitality Scale (SVS)) were administered to participants before and after interventions. Results showed that participants’ levels of negative mood, as measured by different aspects of the POMS questionnaire (tension/anxiety, anger/hostility, depression/dejection, confusion, and fatigue), decreased after exposure to the forest environment. In contrast, both tension/anxiety and anger/hostility increased in the urban street environment. The indicator of negative affect from the PANAS questionnaire also increased after exposure to the urban street environment, whereas the indicator of positive affect based on PANAS was higher in the forest environment than in the urban street environment. Restorativeness and subjective vitality exhibited higher values after exposure to the forest environment in comparison to those from the control and pre-test. The changes in these indicators demonstrate that forest recreation in the snow during winter can significantly increase psychological relaxation in females, as well as show that recreation can be successfully conducted under these winter conditions.

Urbanized areas are struggling with the problem of air pollution and as the number of people living in cities is increasing, the situation is likely to deteriorate. One of the most harmful pollutants is particulate matter (PM). Increased levels of PM in the atmosphere are likely to have a negative impact on human health. Phytoremediation technology could be a solution. It involves plants acting as bio-filters by accumulating particles on, and in the leaves, thus removing the particles from the atmosphere. This study investigates the accumulation of PM including heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs), on the foliage of small-leaved lime (Tilia cordata Mill.) in five Polish cities. There were significantly different PM amounts found in the trees between the cities which related to the different quantities of PM in the atmosphere at these cities. Significant differences were found between cities for the amounts of the different particulate size fractions, and the HMs and PAHs in leaves. Strong winds reduced the amount of PM on leaves, especially the smallest fractions, but no relationship with precipitation was found. The results suggest that T. cordata improves the air quality in cities and can be used as an effective bioindicator for PM air pollution.