Greenspace morphology and momentary stress: Perceived green quality and variation across activity contexts

Psychological stress is a concern in highly urbanized cities, where urban greenspace may support mental well-being. Yet static measures of greenspace emphasize quantity and may miss how people encounter and perceive vegetation morphology during daily mobility. We combined GPS tracking, ecological momentary assessment (EMA), activity diaries and questionnaires from 738 participants in four Hong Kong communities, yielding 3,871 assessments. Nine LiDAR-derived indicators characterized vegetation within 300-m buffers over the preceding 5 min. Mixed models examined associations with perceived green quality and momentary stress across activity contexts; participant-level models examined daytime exposure and stress symptoms. Greater vegetation amount, aggregation, edge density, shape complexity and height-class areas were associated with better perceived green quality, whereas patch density showed the opposite pattern. Better perceived green quality was associated with lower momentary stress within and between participants, with small indirect associations involving vegetation structure. Activity comparisons identified contrasting experiences at work and leisure and variation in the patch-density–quality association that depended on model specification. Comparable indirect associations were not evident for participant-level stress symptoms. These findings support combining vegetation structure with perceived quality to characterize greenspace exposure during daily mobility.