Use of Multi-Temporal LiDAR to Quantify Fertilization Effects on Stand Volume and Biomass in Late-Rotation Coastal Douglas-Fir Forests

Forest fertilization is common in coastal British Columbia as a means to increase wood production and potentially enhance carbon sequestration. Generally, the effects of are determined by measuring sample plots pre- post-treatment, resulting being for limited portion treatment area. Applications remote sensing-based enhanced forest inventories have allowed estimations expand wider forested However, these applications not focused on monitoring silvicultural treatments. The objective this research was examine if multi-temporal application LiDAR area-based method can be used detect volume, biomass, height second-growth Douglas-fir (Pseudotsuga menziesii) stand. study area Vancouver Island fertilized January 2007, were established 2011. acquisitions made 2004, prior fertilization, 2008, 2011, 2016, covering both treated untreated areas. A total 29 paired blocks, comprised four 20 m resolution raster cells, selected either side boundary analysis across several different stand types differing percentage Douglas-fir, site index, age. Random (RF) plot-level models developed estimate stem volume biomass each year acquisition using an approach. Plot level results showed 13% over control from 2005 which similar 14% above-ground stocks estimated tree-ring reconstruction Plot-level RF R2 values 0.86 (volume) 0.92 (biomass) with relative cross-validated root mean square errors 12.5% 11.9% (biomass). For statistical indicated no significant differences or between increments detected treatments blocks. highlight promising potential use inventory methods rapidly assessment beyond stand, block, landscape level.