In the early twentieth century, forestry was one of the most important sectors in Norway and an agitated discussion about the perceived decline of forest resources due to over-exploitation was ongoing. To base the discussion on facts, the young state of Norway established Landsskogtakseringen – the world’s first National Forest Inventory (NFI). Field work started in 1919 and was carried out by county. Trees were recorded on 10 m wide strips with 1–5 km interspaces. Site quality and land cover categories were recorded along each strip. Results for the first county were published in 1920, and by 1930 most forests below the coniferous tree line were inventoried. The 2nd to 5th inventories followed in the years 1937–1986. As of 1954, temporary sample plot clusters on a 3 km × 3 km grid were used as sampling units. The current NFI grid was implemented in the 6th NFI from 1986 to 1993, when permanent plots on a 3 km × 3 km grid were established below the coniferous tree line. As of the 7th inventory in 1994, the NFI is continuous, and 1/5 of the plots are measured annually. All trees with a diameter ≥ 5 cm are recorded on circular, 250 m2 plots. The NFI grid was expanded in 2005 to cover alpine regions with 3 km × 9 km and 9 km × 9 km grids. In 2012, the NFI grid within forest reserves was doubled along the cardinal directions. Clustered temporary plots are used periodically to facilitate county-level estimates. As of today, more than 120 variables are recorded in the NFI including bilberry cover, drainage status, deadwood, and forest health. Land-use changes are monitored and trees outside forests are recorded. Considerable research efforts towards the integration of remote sensing technologies enable the publication of the Norwegian Forest Resource Map since 2015, which is also used for small area estimation at the municipality level. On the analysis side, capacity and software for long term growth and yield prognosis are being developed. Furthermore, we foresee the inclusion of further variables for monitoring ecosystem services, and an increasing demand for mapped information. The relatively simple NFI design has proven to be a robust choice for satisfying steadily increasing information needs and concurrently providing consistent time series.

中文翻译：

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挪威一个世纪的国家森林清查——为过去、现在和未来的决策提供信息。

二十世纪初，林业是挪威最重要的部门之一，关于过度开发导致森林资源减少的激烈讨论正在进行中。为了使讨论基于事实，挪威这个年轻的国家建立了 Landsskogtakseringen——世界上第一个国家森林清单（NFI）。田野工作于1919年开始，以县为单位进行。树木记录在 10 m 宽、间隔 1-5 km 的条带上。沿每个地带记录场地质量和土地覆盖类别。第一个县的结果于 1920 年发布，到 1930 年，针叶树线以下的大多数森林都已被清查。1937 年至 1986 年期间进行了第二次至第五次清查。1954年起，以3公里×3公里网格上的临时样地簇为抽样单位。目前的NFI网格是在1986年至1993年的第六次NFI中实施的，当时在针叶树线以下建立了3 km×3 km网格上的永久地块。自1994年第7次清查起，NFI是连续的，每年测量1/5的地块。所有直径 ≥ 5 cm 的树木均记录在 250 m2 的圆形地块上。2005年，NFI网格扩大到覆盖高寒地区，网格尺寸为3 km×9 km和9 km×9 km。2012 年，森林保护区内的 NFI 网格沿基本方向增加了一倍。定期使用集群临时地块来促进县级估算。截至目前，NFI 中记录了 120 多个变量，包括越橘覆盖度、排水状况、枯木和森林健康状况。监测土地利用变化并记录森林外的树木。自 2015 年以来，为了整合遥感技术，大量研究工作促成了挪威森林资源地图的出版，该地图也用于市一级的小面积估算。在分析方面，正在开发用于长期增长和产量预测的能力和软件。此外，我们预计将纳入更多用于监测生态系统服务的变量，以及对地图信息的需求不断增加。事实证明，相对简单的 NFI 设计是满足稳定增长的信息需求并同时提供一致时间序列的可靠选择。