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.

种子供应是林木种群动态的核心特征之一，种子产量可反映区域环境与生物驱动因子的变化。本研究聚焦北美太平洋西北沿岸上坡地带的真冷杉-铁杉林的球果产量动态，监测周期始于1959年并延续至今。研究人员对冷杉属（Abies）（包括A. amabilis、A. concolor、A. grandis、A. lasiocarpa、A. magnifica、A. procera）、松属（Pinus）（包括P. engelmannii、P. lamberti、P. monticola）以及铁杉属（Tsuga）（包括T. mertensiana）的球果数量开展年度调查，调查覆盖华盛顿州与俄勒冈州9处国家森林内的37个点位共61块样地（最初为10处国家森林，后贝克山与斯诺夸尔米国家森林合并）。在每个样地，研究人员会对单一林分中20~30株样木的球果产量进行目视计数；部分样地在20世纪80年代增补了样木数量。原始数据集包含每株样木每年的球果计数结果、定期测定的树木胸径数据，以及样地点位信息。该数据集可用于分析球果产量的周期性波动规律，以及该区域与气候变化及气候变异性相关的长期变化趋势。