Plant Available Nutrients, Utqiagvik (Barrow), Alaska, Ver. 1

This dataset reports measurements of plant available nutrients made using Plant Root Simulator (PRS) probes (Western Ag Innovations Inc.) during 2012 and 2013 at the Next-Generation Ecosystem Experiments (NGEE) Arctic field site near Utqiagvik (Barrow), Alaska. In 2012, Ca, Mg, K, P, Fe, Mn, Cu, Zn, B, S, Pb, Al, Cd, NO3-N and NH4-N availability were measured during spring, summer and winter from probes installed in the centers, edges and troughs of four polygons in each of four areas of contrasting moisture regime and polygon type (Areas A, B, C, and D of Intensive Site 1). In 2013, probes were installed in centers, edges and troughs of four polygons in each of two areas (A and B, with low-centered and high-centered polygons respectively) at two-week intervals and at 3 soil depths to capture fine-scale seasonal dynamics of NO3-N and NH4-N. PRS probes are ion exchange resin membranes held in plastic supports that are inserted into soil to measure ion supply in situ. The anion and cation exchange with the membrane is intended to mimic plant uptake and thus provide a relevant measure of soil nutrient bioavailability. Measurements are made per area of probe membrane and cannot be converted to concentrations or related to soil volume. This dataset includes five csv files and three pdf files. The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy's Office of Biological and Environmental Research. The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska. Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

本数据集记录了2012年与2013年间，在阿拉斯加州乌特恰维克（Utqiagvik，原称巴罗Barrow）附近的下一代生态系统实验（Next-Generation Ecosystem Experiments, NGEE）北极野外试验场，使用植物根系模拟器（Plant Root Simulator, PRS）探针（西方农业创新公司，Western Ag Innovations Inc.）开展的植物有效养分测定数据。
2012年，研究人员在4个水分状况与多边形地貌类型存在差异的区域（密集试验点1的A、B、C、D区）的每个区域内，于春季、夏季与冬季对4个多边形地貌的中心、边缘和槽谷中安装的PRS探针进行养分有效性测定，涵盖钙（Ca）、镁（Mg）、钾（K）、磷（P）、铁（Fe）、锰（Mn）、铜（Cu）、锌（Zn）、硼（B）、硫（S）、铅（Pb）、铝（Al）、镉（Cd）、硝态氮（NO3-N）与铵态氮（NH4-N）等指标。
2013年，研究人员在两个区域（A区与B区，分别对应低多边形与高多边形地貌）的每个区域内的4个多边形地貌的中心、边缘和槽谷中安装PRS探针，每两周开展一次测定，并设置3个土壤深度梯度，以捕捉硝态氮与铵态氮的精细尺度季节动态变化。
PRS探针是封装于塑料支架内的离子交换树脂膜，可插入土壤中原位测定离子供应情况。其与膜片发生的阴阳离子交换过程可模拟植物吸收行为，因此能够有效表征土壤养分的生物有效性。本次测定结果以探针膜片的单位面积为基准，无法换算为浓度或与土壤体积建立关联。
本数据集包含5个逗号分隔值（Comma-Separated Values, CSV）文件与3个可移植文档格式（Portable Document Format, PDF）文件。
下一代生态系统实验北极项目（NGEE Arctic）是一项旨在通过加深对富碳北极生态系统的预测性理解及其与气候的反馈作用，降低地球系统模型不确定性的研究计划，由美国能源部生物与环境研究办公室资助。
该项目拥有两个野外研究站点：1）位于阿拉斯加州乌特恰维克（Barrow）附近北坡与巴罗环境观测站（Barrow Environmental Observatory, BEO）的北极多边形苔原沿海区域；2）阿拉斯加州诺姆以北苏华德半岛的不连续多年冻土区域的多处地块。
通过观测、实验以及与现有数据集的综合分析，NGEE北极项目为多尺度建模提供了增强的知识库，并推动了美国能源部地球系统模型——能源极端尺度地球系统模型（Energy Exascale Earth System Model, E3SM），尤其是其陆面模型组件（E3SM陆面模型，ELM）——在全球泛北极尺度下的过程表征精度提升。