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Abstract
FVS simulations that do not account for natural tree regeneration after silvicultural treatments that harvest trees, or natural disturbances that kill trees, may overestimate tree growth and underestimate tree mortality, stem density, and ladder fuel development over time. The Westside Fire- and Carbon-Oriented Forest Management Modeling (FCOMM) project aims to quantify fire resistance across forests of western Oregon, Washington, and northwestern California using FVS simulation of business-as-usual management practices (i.e., silvicultural treatments) across >10,000 FIA conditions. Given that abundant tree regeneration post-harvest can reduce the long-term effectiveness of silvicultural treatments aimed at enhancing stand-level fire resistance, accounting for natural tree regeneration within FCOMM FVS simulations is paramount. To address this issue, a natural tree regeneration imputation procedure was adapted from prior research methods (Vandendriesche 2010) using field-observed natural tree regeneration (average small sapling density; 1-3" diameter) measurements across thousands of FIA conditions (stands) and a range of forest structure condition classifications (percent canopy cover * overstory quadratic mean diameter [QMD] classes) as the imputation basis. Two distinct imputation procedures were developed for comparison, based on shade-tolerance groups (aggregated species responses) and species-specific responses. We present the imputation procedure logic and FVS simulation results from its application across 3,799 West Cascades (WC) variant stands, nested within the FCOMM study area.
Parent Publication
Keywords
forest management,
forest planning,
growth and yield,
vegetation dynamics,
habitat modeling,
carbon inventory,
landscape dynamics,
fire,
fuels,
climate change,
economics,
tree-rings
Citation
Busby, Sebastian; Fried, Jeremy. 2024. An FIA-based imputation procedure to account for natural tree regeneration post-treatment in FVS. In: Shaw, John D; Battaglia, Mike A.; Castle, Mark, [comps.]. Sixth Forest Vegetation Simulator Conference; 2023 March 7-9; Fort Collins, CO. Proceedings RMRS-P-81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 10-13.
