Using terrestrial laser scanning to support biomass estimation in densely stocked young tree plantations

The total area of short-rotation tree plantations is increasing globally, one reason being the need to grow sustainable biomass for bio-energy production. Such stands are usually established with a very high stem density, and inventories for biomass estimation require the adaptation of traditional methods. In this study, we tested a novel, efficient, and non-destructive method for biomass estimation relevant to a high-density, short-rotation oak stand of about 16,500 stems ha−1. We used terrestrial laser scanning (TLS) in a single-scan design to measure diameter at breast height (DBH) of all trees within 2 m-radius sample plots. Allometric models were then used to predict the tree biomass from their diameter. Biomass estimates were compared to the true biomass determined after harvesting of the sample plots. Mean absolute error and mean relative error were 12.9 kg and 16.4%, respectively, and the coefficient of determination of the relationship between traditionally measured and scan-based biomass was r2 = 0.65 (p < 0.001). This TLS-based approach is promising as it considerably reduces fieldwork efforts in dense stands compared with traditional diameter tallying by calipers or tapes.