Relationships Among Plant Species Richness, Carbon Density and Habitat Availability Under Forest Management

Forest management regimes are associated with broad-scale variation in relationships among habitat conditions, plant diversity, and biomass carbon stocks, but these relationships remain difficult to compare across management regimes because global datasets differ in resolution, date, and method of construction. We integrated 73,767 forest management locations with raster products for vascular plant richness, terrestrial habitat availability, and biomass carbon density using five forest management categories identified in five analytical fields: F11, F31, F32, F40, and F53. Habitat availability was defined as the fractional coverage or availability of terrestrial habitat types derived from the habitat classification of the International Union for Conservation of Nature, rather than a direct measure of soil fertility, moisture, or site-level microhabitat quality. Habitat availability was weakly associated with ln-transformed plant species richness overall (Pearson r = 0.072, p < 0.001) and moderately associated with ln carbon density (r = 0.427, p < 0.001), whereas ln species richness and ln carbon density were weakly to moderately associated (r = 0.228, p < 0.001). Management-specific correlations differed in strength and direction; the habitat availability–richness relationship was strongest in F32 (r = 0.318, p < 0.001), while the habitat availability–carbon relationship was strongest in F11 (r = 0.320, p < 0.001). Overall, the results support management-dependent, weak-to-moderate global associations rather than causal management effects or site-level thresholds.