Does increasing biodiversity in an urban woodland setting promote positive emotional responses in humans? A stress recovery experiment using 360-degree videos of an urban woodland

possible that the differences in Positive Affect between commenters and non-commenters (who represented over 40% of the sample) might be explained by boredom with the lengthy procedure. However, even though boredom was mentioned in the comments by 30 partici- pants, the completion rate suggests that most of the participants did their best to engage with the experiment. There were notable differences in results from people who noticed elements of nature and those who did not (or did not report doing so). Future research should focus on this aspect. How much do we need to notice nature–to gain a restorative benefit? Are there differences due to more nuanced demographics? Future research could take a stratified approach to deter- mine if nature engagement/knowledge impacts on well-being. Asking people to notice nature seems to help with engagement and subsequently well-being [72–74], but how do background levels of nature literacy impact on emotional responses? It may well be that both a complete lack of knowledge/interest (not noticing or valuing what is seen) or high levels of nature knowledge (e.g. in conservation workers with consequential understanding of negative fac- tors–biodiversity declines, habitat loss etc.) act negatively in terms of promoting well-being. Perhaps only those with a moderate understanding of nature actually have the capacity to receive the health benefits? These factors need testing. Conclusions This study explored the impact of biodiversity on emotional responses but differed from

many previous studies by artificially manipulating, in a controlled manner, the amount of biodiversity on view or inferred through sound. Although the study noted that being in a green (woodland) space decreased negative emotions, there was no significant additional benefit due to increased biodiversity. Being exposed to green space (and different levels of biodiversity) had little impact on the Positive Affect participants reported, but perceiving the location as more biodiverse had a greater effect. Those participants who had positive percep- tions about the environment (e.g. how biodiverse they thought it was) and their engagement with it (by noticing and appreciating its elements) reported more Positive Affect. Noticing biodiversity, therefore, could be a key factor in eliciting positive emotions, however, fewer than 10% of participants indicated they noticed any additional plantings (flowering plants). If perceiving and engaging with biodiversity is necessary to receive an extra boost to mental well-being, a lack of noticing may be preventing many people from gaining the maximum mental health benefit from their green space. In essence, whilst acknowledging some psycho- logical recovery provided by green space in general, one may have to “notice” the good things in nature to optimise those benefits. This data has important implications for policymakers, because not only do urban green spaces need to be engaging and biodiverse, but certain edu- cational processes may need to be included before citizens reap the health benefits such

places can elicit. In essence, “nature blindness” may undermine the salutogenic potential of many green spaces. Supporting information S1 Appendix. Supporting information. Species lists, codes description and perceived biodi- versity crosstabulation. (DOCX) S1 Dataset. Dataset and statistics outputs. (ZIP) PLOS ONE Does increasing biodiversity in an urban woodland setting, promote positive emotional responses in humans? PLOS ONE | https://doi.org/10.1371/journal.pone.0297179 February 7, 2024 15 / 20