5. Conclusions
This study revealed that exposure to olfactory–visual stimuli of a garden plant odor and landscape relaxed and refreshed the subjects’ bodies to a certain extent, and this physiological health effect was greater with regards to the integrated response of the autonomic nervous system and central nervous system than the effect of only the visual or olfactory stimulus. Therefore, in the planning and designing of plant smellscapes in garden green space, it should be ensured that plant odors and corresponding landscapes are present at the same time in order to ensure the best health effect or, in other words, to ensure ‘It penetrates people’s hearts and spleens’.Another finding of this study is that the CNS and ANS showed different physiological responses to the stimulus types associated with the smellscape. Under the olfactory–visual stimulation mode, the degree of the activity of the human central nervous system fell between that under the olfactory alone and only visual stimulation modes, with a compromise effect, while the degree of the excitation of the sympathetic nervous system was much higher than that under any of the single stimulus modes, with a cumulative effect being recorded.All of these findings support the possibility that short-term exposure to olfactory–visual stimuli associated with garden plant smellscapes can induce physical and mental pleasure. From the late 1990s to the early 2000s, people’s interest in aromatherapy soared, but its influence is remains relatively limited. People need specific space and time and must pay certain costs to engage in aromatherapy. In today’s busy society, if people were to take in the interacting stimuli of the fragrant scent of garden plants and beautiful scenery when they visit park green spaces or walk in street green spaces, they may be able to relieve pressure and relax, could be very beneficial to public health. The results of this study provide valuable data for the realization of this possible approach, in addition to contributing to the development of a theoretical basis for the design of odor landscapes in garden plant landscapes.However, this study is subject to some limitations. In terms of the study’s research objects, the subjects were mainly young college students; people of other age groups, education levels and living backgrounds were not involved. More population samples should be included in future studies to further validate the results of this study. Furthermore, although the study’s experimental design, which involved olfactory, visual and olfactory–visual stimuli, was scientific and innovative, there is still a variety of other components in garden green space environments, such as sound. Other environmental stimuli such as sound should be incorporated into future studies as evidence to support the health benefits of garden green space. In terms of the study’s measurement indicators, we only focused on the measurement of physiological indicators, not psychological indicators. Psychological indicators should be measured in future studies in order to verify the results of this study more comprehensively.Although smell, which is directly related to aromatic odor, is the primary factor that triggers the perception of a smellscape, such perception not only involves the sense of smell but also the interaction of multidimensional senses. The future design of garden plant smellscapes should not only focus on odor elements but also make full use of all the perception elements related to smellscapes, i.e., those interacting multidimensional senses, so as to improve the environmental quality of garden green space and give full play to the health effects of garden plant smellscapes.