Outdoor tourism can provide nature therapies. Implementation research for mental healthcare aims to establish psychological mechanisms and specify designs, doses and durations for medical trials. As one component, we tested simultaneous links from senses to emotions, and emotions to self-perceived wellbeing, for 524 tourists at 27 forest reserves in China. We used quantitative surveys, in person, with: 5-point Likert-type scales to measure links; free-text descriptions of their most memorable sensory and emotional experiences during these forest visits; and 7-item Personal Wellbeing Index (PWI) and 10-item Kessler stress index (K10) to measure mental health and wellbeing. We found that Chinese forest tourists perceive strongly (p < 0.00001) that sensory experiences drive emotions, and emotions determine wellbeing. Senses reported were: sight by 86%, sound by 36%, smell by 41%, touch by 18%, temperature by 42%, and humidity by 20%. The number of senses engaged during forest experiences ranged from 1, for 39%, to 6, for 9%. The K10 stress-reduction measure of wellbeing was significantly (p = 0.0272) but weakly (R2 = 0.009) correlated with the number of senses engaged. Future research on mechanisms for mental health benefits to outdoor tourists, and tourist choreography by tour guides and trail signs, should therefore focus on intensity of senses and emotions.