Spatial Patterns of Michelia macclurei and Mytilaria laosensis plantations after 24 Years of Near-Natural Transformation

The spatial pattern of plantations changes after near-natural transformation, but the underlying driving mechanisms remain unclear. To address this issue, we established three permanent plots in monoculture and mixed plantations of native tree species Mytilaria laosensis Lecomte and Michelia macclurei Dandy in southern China. Trees were classified into planted trees and regenerations, and regenerations were further divided into shade-tolerant and shade-intolerant functional groups based on light adaptability. We applied the univariate pair correlation function g ₁₁ ( r ) to analyze the distribution patterns of planted trees and regenerations, and bivariate pair correlation function g ₁₂ ( r ) to analyze spatial correlations between planted trees and regenerations, as well as between functional groups. Results indicate: (1) planted trees exhibited aggregated distributions in all stands at small spatial scales ( r  = 0–2 m, r  = 0–3 m), regenerations showed aggregation across a wider range of spatial scales; (2) spatial correlations between planted trees and regenerations were positive in the Mytilaria laosensis Lecomte monoculture stand and the mixed stand ( r  = 0–2 m), while it was negatively correlated in monoculture stand of Michelia macclurei Dandy ( r  = 2–20 m); (3) spatial correlations between shade-tolerant and shade-intolerant regenerations was negatively correlated in all stands, but at slightly different scales ( r  = 0–2 m, r  = 0–3 m, r  = 0–5 m). These results suggest that planting patterns and functional traits jointly drive spatial pattern shifts in plantations, leading to increased spatial complexity within stands and deepening our understanding of the near-natural transformation process of plantations.