Stress Recovery of Campus Street Trees as Visual Stimuli on Graduate Students in Autumn.

Human stress recovery response to landscapes is under discussion in Chinese settings. The present study aimed to clarify the stress recovery effects of campus street trees on graduate students in autumn. A total of 150 participants (23.75 ± 1.01 years old) completed the Trier Social Stress Test (TSST) and were then randomly assigned to view one of five virtual environments, including the street trees Sophora japonica, Ginkgo biloba, Platanus acerifolia, Koelreuteria paniculata, and the indoor environment (control). Physiological responses were measured by R-R interval and electroencephalography (EEG). Psychological responses were examined through the state version of the State-Trait Anxiety Inventory (STAI-S) and the Perceived Restorativeness Scale (PRS). Results showed that R-R intervals significantly increased while viewing all street trees. Both alpha and beta brainwave activities while viewing S. japonica and G. biloba were remarkably higher than those while viewing P. acerifolia and K. paniculata. The STAI-S scores significantly decreased, and the positive PRS scores were registered after viewing street trees. We concluded that a brief virtual visual experience of campus street trees in autumn has stress recovery effects on graduate students, and the different levels of stress recovery are associated with different types of street trees.

Psycho-Physiological Effects of a Peony-Viewing Program on Middle-Aged and Elderly Individuals at Different Phenological Stages.

To address the question of whether the behavior of humans to view different phenological peony flowers has various effects on their physical and mental parameters, we investigated psycho-physiological responses of 74 participants (61.3 ± 10.78 years old) to environments of pre- and post-viewing tree peonies at four stages, including the exhibition leaf stage (ELS), initial bloom stage (IBS), full bloom stage (FBS), and terminal bloom stage (TBS). Physiological factors were examined using systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), fingertip pulse (FP), blood oxygen saturation (SpO2), and psychological evaluation, which was carried out using the Profile of Mood States (POMS) and State⁻Trait Anxiety Inventory (STAI). The results indicated that the SBP, DBP, HR, and FP levels of participants were significantly reduced after viewing tree peonies, whereas no remarkable alterations in SpO2 were found. The POMS scores of anger⁻hostility (A⁻H), fatigue⁻inertia (F⁻I), tension⁻anxiety (T⁻A), confusion⁻bewilderment (C⁻B), and depression⁻dejection (D⁻D) were significantly lower, but of vigor⁻activity (V⁻A) was higher post-viewing than pre-viewing. Furthermore, participants exhibited markedly decreased anxiety levels according to the STAI. Notably, the changes in measurement indices were more pronounced at the FBS. Our studies demonstrated that a short peony-viewing program, especially at the FBS with completely opened and large tree peony flowers, would be a promising therapeutic method for improving physiological functions as well as an effective psychological relaxation strategy for middle-aged and elderly individuals.