USDA Forest Service, Northern Research Station, Durham, NH, 03824, USA.
USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR, 97331, USA.
Sci Data. 2019 Jan 8;6:180303. doi: 10.1038/sdata.2018.303.
The quantity and condition of downed dead wood (DDW) is emerging as a major factor governing forest ecosystem processes such as carbon cycling, fire behavior, and tree regeneration. Despite this, systematic inventories of DDW are sparse if not absent across major forest biomes. The Forest Inventory and Analysis program of the United States (US) Forest Service has conducted an annual DDW inventory on all coterminous US forest land since 2002 (1 plot per 38,850 ha), with a sample intensification occurring since 2012 (1 plot per 19,425 ha). The data are organized according to DDW components and by sampling information which can all be linked to a multitude of auxiliary information in the national database. As the sampling of DDW is conducted using field efficient line-intersect approaches, several assumptions are adopted during population estimation that serve to identify critical knowledge gaps. The plot- and population-level DDW datasets and estimates provide the first insights into an understudied but critical ecosystem component of temperate forests of North America with global application.
倒伏枯立木（downed dead wood，DDW）的数量和状况正成为控制森林生态系统过程的主要因素，如碳循环、火灾行为和树木更新。尽管如此，如果不是在主要森林生物群落中完全没有，那么对 DDW 的系统清查也很稀疏。自 2002 年以来，美国林务局（US Forest Service）的森林清查和分析计划（Forest Inventory and Analysis program）一直在对所有美国毗邻的林地进行年度 DDW 清查（每 38850 公顷 1 个样地），自 2012 年以来，抽样强度有所增加（每 19425 公顷 1 个样地）。这些数据是根据 DDW 成分和抽样信息组织的，所有这些信息都可以与国家数据库中的大量辅助信息相关联。由于 DDW 的抽样是使用现场高效的线交叉方法进行的，因此在种群估计中采用了一些假设，这些假设有助于确定关键的知识差距。样地和种群水平的 DDW 数据集和估计值首次为北美的温带森林这一具有全球应用的被低估但至关重要的生态系统组成部分提供了深入了解。
