ABSTRACT

Forest productivity is a crucial variable in forest planning, usually expressed as site index (SI). In Nordic commercial forest inventories, SI is commonly estimated by a combination of aerial image interpretation, field assessment and information obtained from previous inventories. Airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) data can alternatively be used for SI estimation, however the economic utilities of the inventory methods have not been compared. We compared seven methods of SI estimation in a cost-plus-loss analysis, by which we added the expected economic losses due to sub-optimal treatment decisions to the inventory costs. The methods comprised direct and indirect estimation from combinations of ALS, DAP and stand register data, and manual interpretation from aerial imagery supported by field assessment and information from previous inventories (conventional practices). The choice of method had great impact on both the accuracy and the economic value of the produced estimates. Direct methods using bitemporal ALS and DAP data gave the best accuracy and the smallest total cost. DAP was a suitable and low-cost data source for SI estimation. Estimation from single-date ALS and DAP data and age obtained from the stand register provided practical alternatives when applied to even-aged stands.

摘要

森林生产力是森林规划中的关键变量，通常表示为站点指数（SI）。在北欧商品林清单中，SI通常是通过航空影像解释，现场评估和从先前清单获得的信息相结合来估算的。可以将机载激光扫描（ALS）和数字航空摄影测量（DAP）数据用于SI估算，但是尚未对清单方法的经济实用性进行比较。我们在成本加损失分析中比较了SI估计的7种方法，通过这些方法，我们将由于次优处理决策而导致的预期经济损失添加到了库存成本中。这些方法包括根据ALS，DAP和林分寄存器数据的组合进行直接和间接估算，以及通过实地评估和以前清单中的信息（传统做法）支持的航空影像人工解释。方法的选择对所产生的估计数的准确性和经济价值都有很大的影响。使用双时态ALS和DAP数据的直接方法可提供最佳准确性和最小的总成本。DAP是用于SI估计的合适且低成本的数据源。从单日ALS和DAP数据估算以及从摊位寄存器获得的年龄，将其应用于均匀老化的摊位是可行的选择。DAP是用于SI估计的合适且低成本的数据源。从单日ALS和DAP数据估算以及从摊位寄存器获得的年龄，将其应用于均匀老化的摊位是可行的选择。DAP是用于SI估计的合适且低成本的数据源。从单日ALS和DAP数据估算以及从摊位寄存器获得的年龄，将其应用于均匀老化的摊位是可行的选择。