SPRUCE Aboveground Vegetation Coverage in Root Ingrowth Core Plots, Marcell Experimental Forest, Minnesota, August 2022

This dataset contains vegetation survey measurements from root ingrowth core plots (Määttä et al. 2025) inside SPRUCE Experiment plots at the Marcell Experimental Forest in northern Minnesota. Vegetation surveys were conducted in 0.25 meter2 plots containing root ingrowth cores on August 8th and 9th, 2022 (2022-08-08 to 2022-08-09). The warming and elevated carbon dioxide (CO2) treatments in the dataset include the full treatment gradient: +0 degrees Celsius (C) (+0 and +500 parts per million (ppm) elevated CO2), +2.25 degrees C (+0 and +500 ppm), +4.5 degrees C (+0 and +500 ppm elevated CO2), +6.75 degrees C (+0 and +500 ppm) and +9 degrees C (+0 and +500 ppm elevated CO2) for both hummocks and hollows. This dataset includes measurements of the height and absolute coverage (%) for each vascular plant and moss species, as well as organic litter and dead overstory vascular plants, and the distance from the grid center to the nearest tree and the species of the nearest tree. These data were used as species-specific aboveground plant metadata for assessing the warming and elevated CO2 response of fine roots across different peatland microtopographical features (hummocks and hollows) and plant functional types (shrub, spruce and larch). This dataset contains one data file in comma separate (.csv) format. Additional metadata are provided: one data dictionary and a file-level metadata file in comma separate (.csv) format and a user guide in PDF (*.pdf) format.

本数据集涵盖取自明尼苏达州北部马塞尔实验森林（Marcell Experimental Forest）SPRUCE实验（SPRUCE Experiment）样地内的根系生土芯样方（root ingrowth core plots）的植被调查测量数据，数据源自Määttä等人2025年的研究。
植被调查于2022年8月8日至9日（2022-08-08至2022-08-09）开展，调查样方面积为0.25平方米，所有样方均布设了根系生土芯。
本数据集涵盖完整的增温与二氧化碳（CO₂）富集处理梯度：针对丘状微地形（hummocks）与凹状微地形（hollows）两类样地，各增温梯度均设置了两种CO₂处理水平——大气CO₂背景浓度与500ppm富集CO₂，具体增温梯度包括0℃、+2.25℃、+4.5℃、+6.75℃与+9℃。
本数据集包含各维管植物、苔藓物种的株高及绝对盖度（%）数据，同时收录有机枯落物、枯亡上层维管植物的相关测量值，以及样方网格中心到最近邻树的距离与该邻树的物种信息。
上述数据被作为物种特异性地上植物元数据，用于评估不同泥炭地微地形特征（丘状与凹状微地形）及植物功能型（灌木、云杉、落叶松）下，细根对增温与CO₂富集的响应规律。
本数据集包含1份逗号分隔（.csv）格式的数据文件。配套补充元数据包括：1份逗号分隔（.csv）格式的数据字典与文件级元数据文件，以及1份PDF（*.pdf）格式的用户指南。