Data and code: relative density and forest disturbance on the FIA subplot design (conterminous United States, 1999 to 2026)

Aggregate results, figures, and analysis code for the manuscript "Forests at higher relative density are disturbed more often, mainly by insects, disease, and weather" (in preparation). Relative density (RD, stand density index divided by its site maximum) at one Forest Inventory and Analysis (FIA) visit is related to disturbance recorded at the next for 228,797 remeasured plot visits on 98,525 plots in the 48 conterminous US states, 1999 to 2026, treating the four fixed-area subplots of each plot as the sample with no division by FIA condition. The primary odds ratio of disturbance per 0.5 RD is 1.25 (95% CI 1.16 to 1.35 with errors clustered by ecological section). The record holds the occurrence curves, agent-specific odds ratios, ten model specifications, density-measure comparisons, the SDI and SDImax decomposition, stress checks, hexagon and ecological section summaries behind the maps, subplot-scale checks, and an audit of the earlier condition-based frame. A graphical abstract (00_rd_disturbance_subplot_graphical_abstract.png) is the lead file, and README.md gives the file guide, order of execution, inputs not deposited, and a correction to the latest-remeasurement specification. No FIA plot identifiers or coordinates are included. The plot frames are rebuilt from the public FIA DataMart with the deposited scripts, and the maps use the public perturbed coordinates only to assign plot visits to cells. This analysis replaces the condition-based analysis of earlier preprint versions (10.5281/zenodo.23673228).