ABSTRACT

Cross-cutting of felled trees into logs (“bucking”) is a critical step in converting standing timber into end products, as it predetermines and limits number, type and value of products that can be produced from the logs. Bucking by chainsaw is currently not aided by information technology and volume and value recovery depend on the chainsaw operator’s proficiency. A recently presented novel mobile device-based application (“T4E Bucking App”) for assisting value-maximized bucking by chainsaw was evaluated during harvesting in a mature beech stand regarding taper curve estimation accuracy. Further, its bucking patterns were benchmarked against an experienced chainsaw operator’s choice and time consumption for app operation was determined. Taper curves were inadequately approximated and log mid diameters (1.0 cm, SD=2.4) and log volume (0.02 m³ under bark [UB] m³, SD=0.04) were significantly overestimated. Consequently, total observed volume (–8.7%) and value (–8.1%) were smaller than estimated. Inappropriate pricing and insufficient top diameters caused further reductions. Thus, total recovered volume (59.61 m³ UB; –8.8%) and value (€2,099.66; –8.6%) were smaller than estimated. Chainsaw operator’s totals differed marginally (58.59 m³ UB; €2,117.99). About 85% of the variation of time consumption for working with the app was explained by tree volume and number of grade sections. After accounting for time consumption, net value recovery was 5.1% lower than in the chainsaw operator’s case. The T4E Bucking App nevertheless represents a first step towards digitalization of motor-manual bucking and may soon be enhanced by more accurate taper curves derived from terrestrial laser scanning data.

摘要

将砍伐的树木横切成原木（“弯曲”）是将立木转化为最终产品的关键步骤，因为它预先确定并限制了可从原木生产的产品的数量、类型和价值。电锯锯切目前没有信息技术的帮助，数量和价值的恢复取决于电锯操作员的熟练程度。最近提出的一种基于移动设备的新型应用程序（“T4E Bucking App”），用于在成熟的山毛榉林架上收获期间，评估了电锯进行价值最大化的弯曲估计的锥度曲线估计精度。此外，根据经验丰富的链锯操作员的选择对其反冲模式进行了基准测试，并确定了应用程序运行的时间消耗。锥度曲线未充分近似，对数中径 (1.0 cm, SD=2.4) 和对数体积 (0.02 m³树皮下 [UB] m ³，SD=0.04) 被显着高估。因此，观察到的总体积 (–8.7%) 和值 (–8.1%) 小于估计值。定价不当和顶部直径不足导致进一步减少。因此，总回收量（59.61 m ³ UB；–8.8%）和价值（2,099.66 欧元；–8.6%）小于估计值。电锯操作员的总数略有不同 (58.59 m ³UB; 2,117.99 欧元）。大约 85% 的使用该应用程序的时间消耗变化是由树木体积和等级部分的数量来解释的。计入时间消耗后，净值回收率比链锯操作员的情况低 5.1%。尽管如此，T4E Bucking App 代表了电动手动降压数字化的第一步，并且可能很快会通过来自地面激光扫描数据的更准确的锥度曲线得到增强。