Peat carbon, δ14C, macrofossil, and humification data from a thawing permafrost peatland in western Canada

The data provided in one xlsx file has five tabs: read me, bulk density and LOI, carbon content, FTIR and C:N, radiocarbon, and plant macrofossils. The same data is available in separate csv files and all data files are included in one zip file, except for a read me file wihcih is in txt format.. \"Read me\" contains descriptions of all column headers and data. It provides units of measurement for each. \"Bulk density and LOI\" contains the bulk density and loss-on-ignition values of peat samples. Bulk density was used with measured carbon content to calculate carbon stocks. LOI was used to aid in identifying transitions between peatland developmental stages. Peat was first dried at 110°C to calculate bulk density and then combusted at 550°C to determine LOI. Both bulk density and LOi were determined according to Chambers et al (2011). \"Carbon content\" contains the measured carbon content of peat samples. Measurements were determined using a Eurovector EA 3000 Elemental Analyzer (HEKAtech, Wegberg, Germany) from a homogenized sample. A site average (45%) carbon content was used with bulk density measurements to calculate carbon stocks. \"FTIR and C:N\" contains Fourier transform infrared (FTIR) spectroscopy and molar C:N ratios from peat samples. We analyzed samples for FTIR on an Agilent 660 FT-IR spectrometer (Agilent Technologies Inc., Santa Clara, CA, USA). Calculated molar C:N ratios, were determined using a Eurovector EA 3000 Elemental Analyzer (HEKAtech, Wegberg, Germany) from a homogenized sample. The mean carbon content of peat was 45 ± 3.6% (n = 45). \"Radiocarbon\" contains the lab ID, uncalibrated age, fraction modern, calibrated 1-sigma age, Bacon model age, material dated, and stratigraphic significance for peat samples across all eight cores. Peat samples were dated using 14C analysis with accelerator mass spectrometry (AMS) at the A. E. Lalonde AMS Laboratory, Ottawa. Bacon model age represents age-depth models that were estimated using the BAcon software (Blaauw and Christeny 2011) \"Plant macrofossils\" contains measurements from a number of depths across all cores. It contains estimates of % presence of Sphagnum, brown moss, sedge, ligneous matter, and ericaceous rootlets using five ranges (≤ 1%, 1 – 10%, > 10 – 50%, > 50 – 90%, and > 90%) of percentage of peat volume acquired from the mean of five different estimates per 1 cm section. Plant needles and leaves are reported as individuals per cm3. Along with bulk density, LOI,and radiocarbon dates, plant macrofossils were used to identify the main transitions between macrofossil assemblages, peatland stages, and permafrost history at the study site.

本数据集以单个XLSX文件提供，内含6个工作表：说明文档（read me）、容重与烧失量（bulk density and LOI）、碳含量、傅里叶变换红外光谱与碳氮比（FTIR and C:N）、放射性碳测年（radiocarbon）以及植物大化石（plant macrofossils）。该数据集同时提供单独的CSV格式副本，所有数据文件均打包于单个ZIP压缩包内，仅说明文档采用TXT格式单独发布。

其中“说明文档”包含所有列标题与数据字段的详细释义，并标注了各指标的测量单位。

“容重与烧失量”工作表收录泥炭样品的容重与烧失量（Loss-On-Ignition, LOI）数据。容重与实测碳含量结合可用于计算碳储量；烧失量则用于辅助识别泥炭地发育阶段的转换界线。泥炭样品先经110℃烘干以计算容重，随后在550℃下灼烧以测定烧失量，两项指标的测定方法均遵循Chambers等（2011）的研究规范。

“碳含量”工作表包含泥炭样品的实测碳含量数据。所有样品经均质化处理后，采用Eurovector EA 3000元素分析仪（德国韦格贝格HEKAtech公司）完成测定。本研究采用45%的样点平均碳含量结合容重测量值计算碳储量。

“傅里叶变换红外光谱与碳氮比”工作表收录泥炭样品的傅里叶变换红外光谱（Fourier Transform Infrared Spectroscopy, FTIR）数据与摩尔碳氮比（C:N）。本研究采用Agilent 660 FT-IR光谱仪（美国加利福尼亚州圣克拉拉安捷伦科技有限公司）完成FTIR光谱分析；摩尔碳氮比则通过均质化样品，采用前述Eurovector EA 3000元素分析仪测定计算得到。本次研究中泥炭样品的平均碳含量为45±3.6%（n=45）。

“放射性碳测年”工作表包含全部8个岩芯泥炭样品的实验室编号、未校正年龄、现代碳分数、校正后1σ年龄、BAcon模型年龄、测年材料以及地层学意义。泥炭样品的14C测年采用加速器质谱（Accelerator Mass Spectrometry, AMS）技术，于渥太华A. E. Lalonde加速器质谱实验室完成。BAcon模型年龄指采用BAcon建模软件（Blaauw与Christeny, 2011）估算得到的年龄-深度模型结果。

“植物大化石”工作表收录全部岩芯多个深度层级的测量数据，涵盖泥炭藓（Sphagnum）、褐藓、莎草、木质物质以及欧石楠属细根的体积占比估算值，估算采用5个区间：≤1%、1%–10%、>10%–50%、>50%–90%以及>90%，该占比基于每1cm泥炭段的5次独立估算的平均值计算得到。植物针叶与叶片以每立方厘米的个体数为单位记录。结合容重、烧失量与放射性碳测年数据，植物大化石数据可用于识别研究区的大化石组合转换、泥炭地发育阶段以及冻土历史。