Hao and colleagues disaggregate “green” into structure, species richness and colour diversity, challenging the blunt equivalence between vegetation quantity and environmental quality. Their factorial experiment finds that each dimension can increase preference and perceived restoration, but their interactions are neither simply additive nor indefinitely beneficial. Medium complexity can outperform maximal complexity, and colour exerts a particularly strong influence. The iconic idea is therefore that ecological and perceptual diversity must be composed, not merely accumulated. Methodologically, the paper uses controlled virtual scenes and a 2×2×2 design to isolate coupled effects that conventional green-space metrics conceal. The broader intellectual bridge is to landscape architecture and information theory: urban vegetation is read as a structured field of difference whose effects depend on relations among components. The work makes “green space” epistemically finer-grained, moving urban environmental research from area-based measurement toward compositional intelligence.
