Linking forests, coasts, and people: social media insights into sentiment and wellness perceptions in China’s nature reserves

• Forest reserves offer restorative and immersive experiences for individual psychological well-being. • Coastal reserves promote social bonding and relaxation through group activities and open environments. • Forests mainly support personal health, while coasts foster collective wellness. • Landscape structure and trail systems drive wellness in forests. • Climatic comfort and blue-green space are key for coastal wellness experiences. Nature reserves (NRs) are vital for ecological conservation and play an increasingly important role in public well-being in China. However, the social and emotional dynamics underlying visitor wellness perceptions across different reserve types remain underexplored. In this study, we analyzed a dataset of 549,682 valid comments collected from Douyin and CTrip, covering 474 National Nature Reserves (NNRs) in China between 2016 and 2024. Using natural language processing and StructBERT-based sentiment classification, we quantified the Perceived Sentiment Index (PSI) and identified wellness-related themes via Latent Dirichlet Allocation (LDA) topic modeling. We further integrated correlation analysis and SHAP-based machine learning interpretation to assess how ecological, climatic, infrastructural, and socioeconomic factors shape the Wellness Topic Score (WTS). The results revealed that forest and coastal NNRs received the highest levels of positive sentiment, with PSI values of 0.82 and 0.88, respectively. Forest reserves were most strongly associated with restorative and immersive experiences, while coastal reserves emphasized social bonding and relaxation. Spatial and temporal analysis indicated significant regional and seasonal variations in wellness perception, with forest NNRs showing peaks in spring and autumn, and coastal NNRs peaking in summer. SHAP interpretation demonstrated that wellness perception in forest reserves was primarily driven by landscape structure and trail systems, whereas in coastal reserves, climatic comfort and blue-green space ratio were dominant factors. Our findings provide robust quantitative evidence for differentiated health management in protected areas and enhance understanding of how digital narratives reflect and shape collective well-being in the context of large-scale nature–human interactions.