Coupling analysis of community structure and color composition in autumn near-natural plant landscapes: a case study of Hefei City

To investigate the systematic coupling relationship between near-natural plant community structure and color characteristics, quantitatively analyze the nonlinear response mechanisms between structure-color interactions affecting visual quality, and provide theoretical support for scientific optimization of urban green space plant configurations.

Typical near-natural plant communities in Hefei urban green spaces were selected as research subjects. A comprehensive evaluation framework incorporating 8 structural indicators and 11 color indicators was established through the integration of scenic beauty estimation (SBE), HSV color quantification, and coupling degree analysis.

1) Visual quality of near-natural plant landscapes in the study area exhibited distinct “moderate” characteristics, with Grade III (medium) landscapes predominating (42.2% exterior landscapes, 33.3% interior landscapes), while the proportion of Grade IV (better) interior landscapes (35.6%) was significantly higher than that of exterior landscapes (17.8%); 2) Color quantity (r=0.30, P<0.01), saturation ratio (r=0.34, P<0.05), and dominant hue ratio (r=0.29, P<0.01) demonstrated significant positive correlations with visual quality, whereas hue ratio showed a negative correlation (r=-0.20, P<0.01); 3) Factor analysis extracted four structural factors accounting for 73.5% of cumulative variance, among which the community density factor exerted the strongest regulatory effect, with coupling degrees exceeding 0.6 across multiple color indicators.

The visual quality of existing near-natural plant community configurations requires enhancement. From a color characteristic perspective, moderate color complexity best promotes landscape visual quality; structurally, community spatial organization most significantly influences color richness and hierarchical perception. For near-natural plant landscape development, we recommend prioritizing vertical structural design to enrich spatial experience, implementing color configuration strategies with “clear primary-secondary hierarchy and rich layering,” and employing precise adaptive management to ensure sustained landscape effects.