Modeling Juvenile Stand Development and Fire Risk of Post-Fire Planted Forests under Variations in Thinning and Fuel Treatments Using FVS–FFE

In the past, dry mixed conifer forests of California’s Sierra Nevada mountains experienced frequent low to severity fires. However, due fire suppression and past management, forest structure has changed, new regimes are characterized by large, high fires which kill a majority overstory trees. These disturbance patterns require novel approaches regenerate as they not adapted We forecasted growth behavior young plantations for 100 years into future using Forest Vegetation Simulator (FVS) its Fire Fuels Extension (FFE). these simulations, we tested combinations different fuel treatments (mastication only, mastication with prescribed burning, no fuels treatments) thinning intensities (residual densities 370 SDI (stand density index), 495 SDI, 618 (TPH), thinning) on stand potential analysis variance. compared crowning index at end simulation age when flame length, basal area mortality, type reached between treatment, intensity, original management stands (plantation PCT [precommercial thinning], plantation without PCT, natural regenerating stands). comparisons essential identify treatment categories reduce risk. found an overall pattern decreasing crown occurrence induced mortality across all simulations increasing canopy base height bulk density. particular, burning transitioned from types surface 10 earlier only or treatment. Furthermore, pre-commercially thinned states in un-thinned naturally stands. Stands went below 25% reference threshold 11 17 before respectively. addition, 9 5 regenerated stands, Mastication (MB) was most effective quickly reducing consuming fuels, thus drastically lowing length (e.g., MB 0.6 m [1.3 m] [1.4 m]). intensive reduced risk active spreading through stand. Prioritizing possible, (both below) ways improve resistance plantations. Our results highlight stressors that post-fire planted experience how silvicultural interact over time risk, demonstrates importance treating early effectiveness treatments.