Experiences in natural environments can enhance human wellbeing and promote the recovery of physiological and psychological health. During the COVID-19 pandemic, university students' activity off-campus was limited, thus, the campus environment was particularly important for the recovery of students' physiological and psychological health. Although the benefits of sustained natural exposure are obvious for people's physiological and psychological health, the effects of brief exposure on physiological and psychological are unclear. In the present study, four types of campus environments, including square space, dense forest space, sparse forest space, and waterfront space, were selected to explore the transient recovery effects of different types of campus environments. Sixty university students were recruited, measuring their systolic blood pressure, diastolic blood pressure, and heart rate as physical parameters to assess stress recovery. Respondents also reported scores about their personal feelings in questionnaires to evaluate their psychological states. Both physiological and psychological indicators responded to the brief natural exposure (5 min), and physiological and psychological health was restored. However, only the recovery amounts of psychological indicators were significantly different in waterfront space, dense forest space, and sparse forest space. These results indicate that being compare with other spaces, the brief exposure in the waterfront space was the most beneficial to students' psychological health recovery. This recovery was attributed to the great role played by the sense of escape, but after the brief exposure, the attraction and compatibility of the environment would hinder the psychological health recovery. In conclusion, according to tests on both physiological and psychological aspects, the waterfront environment on campus is the best choice for students' transient health recovery.

As an ornamentally and medicinally worthy plant, Hosta plantaginea (Lam.) Aschers. has the adapted capacity to survive cold temperate monsoon climates in Northeastern China. However, its use is limited by the soil alkalization of urban gardens. Our pre-experiment found that Hosta ‘Golden Cadet’ has the potential to be alkali-tolerant. Hence, tissue-cultured seedlings of Hosta ‘Golden Cadet’ were used as experimental material. Its related growth, physiology, and transcripts were examined to reveal the molecular mechanism of Hosta plantaginea in response to alkali stress. The results show that the development of Hosta ‘Golden Cadet’ was affected by alkali stress. In comparison with the control, malondialdehyde (MDA) content increased by 4.28-fold at the 24th hour, superoxide dismutase (SOD) activity increased by 49% at the 6th hour, and peroxidase (POD) activity and soluble sugar (SS) content increased by 67% and 30% at the 12th hour, respectively. The RNA-seq analysis revealed that Hosta ‘Golden Cadet’ gene expressions at 0 h, 6 h, 12 h, 21 h and 48 h differed after 200 mmol/L NaHCO₃ treatment. During 48 h under alkali stress, 2366 differentially expressed genes were found. The transcription factors MYB, AP2/ERF, and WRKY were activated in differentially expressed genes. The KEGG analysis found that phytohormone signaling pathways, starch and sucrose metabolism, and phenylpropane production were activated in Hosta ‘Golden Cadet’ in response to alkali stress. In summary, Hosta ‘Golden Cadet’ can reduce membrane damage by improving osmoregulation and antioxidant capacity, increase sucrose and starch metabolism, and regulate phenylpropane biosynthesis by activating transcription factors and inducing related phytohormone signaling, mitigating the effects of alkali toxicity. These findings guide an investigation into the mechanism of alkali tolerance in Hosta plants, screening alkali tolerance genes, and selecting and breeding novel alkali-tolerant Hosta plantaginea cultivars.

Cadmium (Cd) is widely dispersed in the environment and has emerged as a major environmental contaminant. Although Salix viminalis shows potential for phytoremediation of Cd pollution, the defence mechanism of its roots against heavy metals remains unclear. This study explores the adaptive response of S. viminalis roots to Cd stress from physiological, transcriptomic, and metabolomic perspectives. The results suggest that Cd stress exerts inhibitory effects on root growth and development. Compared with the control (Cd-free), the root volume and dry weight of S. viminalis exposed to Cd decreased by 26% and 29%, respectively. After exposure to Cd stress for 14 and 21 days, the Cd content in the roots increased by 117-fold and 134-fold, the hydrogen peroxide content increased by 89% and 110%, and the malondialdehyde content increased by 82% and 88%, respectively. This phenomenon can be attributed to the fact that the continuous accumulation of Cd in the roots may have aggravated the degree of lipid peroxidation. A total of 9171 differentially expressed genes (DEGs) and 169 differential metabolites (DIMs) were identified through transcriptomic and metabolomic analyses. Further combined analyses revealed the potential roles of several pathways in the defensive response of S. viminalis roots against Cd stress, including plant hormone signal transduction, thiamine metabolism, glycolysis, glycerophospholipid metabolism, and other pathways. Notably, the feedback regulatory effects formed by thiamine metabolism and hormone signal transduction related to auxin, jasmonic acid, and salicylic acid play a crucial role in the early stage when roots are exposed to Cd stress. These effects mobilized osmotic adjustment in roots by enhancing saccharide metabolism and activated the Cd detoxification process by altering lipid metabolism, thereby contributing positively to the defence of willow roots against Cd stress. These findings provide insights into the adaptive mechanism of S. viminalis roots in response to Cd and the application of fast-growing woody plants in heavy metal phytoremediation.