REGIMPUTE: A Customizable Forest Inventory-Based Mean Imputation Method to Account for Natural Tree Regeneration in the Forest Vegetation Simulator (FVS)

Natural tree regeneration is an important component of forest development that affects stand growth, mortality, and the severity of natural disturbances (e.g., wildfire) over time. The Forest Vegetation Simulator (FVS) largely lacks endogenous tree regeneration models, and thus does not simulate this key process of forest development by default. To date, few exogenous models or tools exist to account for natural tree regeneration in FVS, and especially those that were developed to interface directly with FVS, can be operationalized by non-experts, and applied systematically across broad geographies. To address this issue, we developed REGIMPUTE – a customizable forest inventory-based mean imputation methodology that can add natural tree regeneration into FVS simulations over time. REGIMPUTE utilizes an open-source workflow and a robust sample of empirical observations (Forest Inventory and Analysis [FIA] data) to summarize observed mean natural tree regeneration responses by species at the FVS variant level, across a broad range of forest structural states. REGIMPUTE is operationalized via customizable keyword files that can be edited for varying simulation timelines, conditionality, and user-desired complexity and precision. As stand structure changes over time due to growth, mortality, and disturbance, REGIMPUTE adds species-specific and structural-state appropriate natural tree regeneration into simulations, while accounting for natural tree regeneration that may already be present.

File package includes (1) methodology documentation, (2) data files and templates, (3) FVS-ready regen keyword files for all FVS variants, and (4) R script workflow that can be used to largely automate custom empirical sample estimation and keyword file generation based on user-defined criteria.

Please use citation:

Busby, S., Giovannoni, L., Swann, D. & Castle, M. 2024. REGIMPUTE: A customizable forest inventory-based mean imputation method to account for natural tree regeneration in the Forest Vegetation Simulator (FVS). Version 1.1. Dataset. Figshare. https://doi.org/10.6084/m9.figshare.26876338