Cone production of upper slope conifers in the Cascade Range of Oregon and Washington, 1959 to present

Seed supply is a key feature of tree population dynamics, and seed production may be indicative of environmental and biological drivers. This study examines cone production in upper-slope, true fir-hemlock forests of the Pacific Northwest, starting in 1959 to the present. Annual surveys of cone counts of Abies spp. (A. amabilis, A. concolor, A. grandis, A. lasiocarpa, A. magnifica, A. procera), Pinus spp. (P. engelmannii, P. lamberti, P. monticola), and Tsuga spp. (T mertsiana) have been conducted at sixty-one plots in 37 locations in nine national forests in Washington and Oregon (originally 10 national forests, but Mt. Baker and Snoqualimie were combined). At each site, a visual count is made of cone production in each of a number (20-30) trees in a stand of one tree species. At some plots, additional trees were added in the 1980s. Primary data include numbers of counts per tree per year, periodic measurements of tree diameter, and the names of the sites. These data illustrate the periodicity of cone production cycles, as well as longer trends associated with climate change and variability in the region.

种子供应是树木种群动态的核心特征，种子产量可作为环境与生物驱动因子的指示性指标。本研究针对1959年至今太平洋西北地区坡地上部的真冷杉-铁杉林的球果产量展开调查。研究人员在华盛顿州与俄勒冈州9处国家森林的37个地点共设置61个样地，每年对冷杉属（Abies）、松属（Pinus）和铁杉属（Tsuga）的物种开展球果计数调查，其中冷杉属包含6个物种：A. amabilis、A. concolor、A. grandis、A. lasiocarpa、A. magnifica、A. procera；松属包含3个物种：P. engelmannii、P. lamberti、P. monticola；铁杉属包含T. mertsiana。该调查最初覆盖10处国家森林，后贝克山与斯诺夸尔米国家森林合并为一处。在每个样地，研究人员会对单一林分中的20至30株样木的球果产量进行目视计数；部分样地在20世纪80年代补充了新增样木。核心原始数据包括每株样木每年的球果计数结果、定期测定的树木胸径，以及样地名称。该数据集可用于揭示球果生产周期的周期性特征，以及该区域与气候变化和气候变异性相关的长期变化趋势。