Farris, S., Dempsey, N., McEwan, K., Hoyle, H. and Cameron, R. (2024) ‘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’, PLOS ONE, 19(2), e0297179. https://doi.org/10.1371/journal.pone.0297179.

The experiment distinguishes ecological variation from the perception of ecological variation. After a mild stress induction, 372 participants watched panoramic recordings of the same urban woodland manipulated to present four degrees of species richness. Negative affect decreased across the conditions without significant differences between biodiversity levels; positive affect, however, was greater among participants who perceived the scene as more biodiverse. Attention to flowers and trees appeared in comments associated with more positive responses. This is neither proof that biodiversity is irrelevant nor proof that subjective appreciation overrides ecology. The controlled visual exposure establishes a narrower but crucial asymmetry: materially varied scenes and noticed differences do not map onto one another automatically. The use of mediated, stationary observation also prevents unqualified transfer to mobile encounters in an actual woodland. Precisely in that separation lies the paper’s conceptual value. Environmental design, experimental psychology and visual media meet at the point where a landscape’s measurable properties cease to predict the full range of its experiential consequences.