Late Holocene tundra fires and linkages to climate and vegetation in northern Alaska

Charcoal particles in lake-sediments can reveal past fires and linkages to climate and vegetation change. We use analyses of charcoal accumulation rates from two lakes (Lake I4 and Kirk Lake) on the Alaskan North Slope to reconstruct past fire activity, and charcoal morphology to identify changes in fuel sources. This dataset contains 1) chronological data for both lake-sediment cores used to construct age-depth models (Pb-210 and radiocarbon), 2) magnetic susceptibility measurements for both cores, 3) macroscopic charcoal particle counts for both sites at three size fractions (90-125µm, 125-250µm, and >250µm), and 4) charcoal morphology (classes defined in associated Arctic Science publication). ,  210Pb data was generated vis gamma spectrometry on a Mirion HPGe small anode germanium (SAGe) well detector. Activities for 210Pb (46.5 keV) and 226Ra (calculated from average of 214Pb (351.9 keV) and 214Bi (609.3 keV) activities) presented.  Radiocarbon ages were measured from macrofossil material extracted from cores and submitted to the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) for AMS 14C dating. Reported 14C ages were calibrated with the INTCAL 20 dataset  using CALIB version 8.2.  Magnetic susceptibility was measured on split core surfaces (continuous measurements) on a Geotek MSCL-S system with a Barrington MS-C point meter.  Charcoal particles were sieved from measured volumes of wet sediment with a sieve cascade of 90, 125, and 250 µm, and particles counts were enumerated for each size fraction.  Charcoal morphologies for all particles >90 µm were identified (see publication for full methodology and references). Morphotypes..., # Late Holocene Tundra Fires and Linkages to Climate and Vegetation in Northern Alaska Dataset DOI: [10.5061/dryad.tb2rbp0dd](10.5061/dryad.tb2rbp0dd) ## Description of the data and file structure Charcoal counts (three size fractions), charcoal morphology, and chronological control from two sites on the Alaskan North Slope, near Toolik Field Station. Sites are Lake I4 (Toolik LTER designation) and Kirk Lake (informal name). Data was collected to provide insight into fire history in the region over the past 7000 years. Please see publication for methodological details (Frank-Depue, L., and M.L. Chipman, 2025, *Arctic Science*). ## Files and Variables **Frank-Depue_and_Chipman_2025_DRYAD.xlsx**: Tabs within this excel file and descriptions listed below. ***Metadata***: this tab contains study and site information, a list of all variables and abbreviations, and missing value designations for all data tabs ***Chronology-Data-Lake-I4***: chronological data for Lake I4, core RTS7U2 ...,湖泊沉积物中的炭颗粒可揭示过去的火灾事件，并关联气候与植被变化。我们对阿拉斯加北坡的两个湖泊——I4湖与柯克湖——的炭堆积速率开展分析，重建区域过去的火灾活动历史，并通过炭颗粒形态识别燃料来源的变化。本数据集包含以下4部分内容：1）用于构建年龄-深度模型的两处湖泊沉积物岩芯的年代学数据（铅-210与放射性碳定年）；2）两处岩芯的磁化率测量数据；3）两个采样点三种粒径组分（90~125 μm、125~250 μm以及＞250 μm）的宏观炭颗粒计数数据；4）炭颗粒形态数据（分类标准见相关《北极科学》（Arctic Science）期刊论文）。 210Pb数据通过Mirion HPGe小型阳极锗（SAGe）井型探测器的γ能谱法测得。文中给出了210Pb（46.5 keV）与226Ra（由214Pb（351.9 keV）和214Bi（609.3 keV）的活度平均值计算得到）的活度值。 放射性碳年龄由从岩芯中提取的大化石材料测得，并送至美国国家海洋科学加速器质谱中心（National Ocean Sciences Accelerator Mass Spectrometry, NOSAMS）开展加速器质谱（Accelerator Mass Spectrometry, AMS）14C定年。报告的14C年龄采用CALIB 8.2版本工具，结合INTCAL 20数据集完成校准。 磁化率在拆分后的岩芯表面通过Geotek MSCL-S系统搭配Barrington MS-C点式测量仪进行连续测量。 炭颗粒通过90、125、250 μm的筛网级联从定量体积的湿沉积物中筛分得到，并对每个粒径组分的颗粒进行计数。 所有粒径＞90 μm的炭颗粒均完成形态鉴定（完整实验方法与参考文献见已发表论文）。形态类型……# 阿拉斯加北部晚全新世苔原火灾及其与气候和植被的关联 数据集DOI：[10.5061/dryad.tb2rbp0dd](10.5061/dryad.tb2rbp0dd) ## 数据与文件结构说明 本数据集包含阿拉斯加北坡图勒野外站附近两个采样点的炭颗粒计数（三种粒径组分）、炭颗粒形态数据以及年代学控制数据。采样点分别为I4湖（图勒长期生态研究站点命名）与柯克湖（非正式命名）。本数据旨在揭示该区域过去7000年以来的火灾历史。实验方法细节请参阅已发表论文（Frank-Depue, L. 与 M.L. Chipman, 2025, *Arctic Science*）。 ## 文件与变量说明 **Frank-Depue_and_Chipman_2025_DRYAD.xlsx**：该Excel文件包含多个工作表，各工作表说明如下。 ***Metadata（元数据）***：该工作表包含研究与采样点信息、所有变量及缩写列表，以及所有数据工作表的缺失值标记规则。 ***Chronology-Data-Lake-I4***：I4湖岩芯RTS7U2的年代学数据。 ……