SPRUCE: Sphagnum Carbon, Nitrogen and Phosphorus Concentrations in the SPRUCE Experimental Plots

This data set reports the concentrations of carbon (C), nitrogen (N), and phosphorus (P) in capitula, current year stems, and one-year old stem tissue of Sphagnum from 2016-2018. Measurements are continuing and new data will be appended as they become available. Three types of Sphagnum were sampled -- S. angustifolium/fallax from hummocks (AngFal_Hum), S. angustifolium/fallax from hollows (AngFal_Hol), and S. magellanicum from hummocks (Mag_Hum) from SPRUCE experimental study plots. Measurements were made in 10 enclosures comprising five levels of temperature elevation in ambient CO2 and five levels in elevated CO2. Measurements also were made in two ambient (no enclosure) plots. Nutrient concentrations were analyzed in conjunction with assessment of Sphagnum growth, which was measured in 3.79-cm diameter mesh columns collected every October and are described in the related dataset (https://doi.org/10.25581/spruce.049/1426474). The SPRUCE experiment is being conducted at the 8.1-ha S1 bog forest site in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

本数据集记录了2016-2018年间采集的泥炭藓（Sphagnum）头枝、当年生茎及一年生茎组织中的碳（C）、氮（N）与磷（P）浓度。监测工作仍在持续，后续将追加发布新增数据。本次共采集三类泥炭藓样品，均采自SPRUCE实验样地：来自草丘的狭叶泥炭藓/偏叶泥炭藓（AngFal_Hum）、来自藓塘的狭叶泥炭藓/偏叶泥炭藓（AngFal_Hol），以及来自草丘的马格卢瓦尔泥炭藓（Mag_Hum）。实验设置10个密闭培养箱，其中5个处于环境CO₂浓度下，设置5级温度升高梯度；另外5个处于高CO₂浓度下，同样设置5级温度升高梯度。此外还在2个无密闭培养箱的环境CO₂对照样地开展了相关测定。本研究同步分析了养分浓度与泥炭藓生长状况：泥炭藓生长量通过每年10月采集的直径3.79 cm的网柱样品进行测定，相关细节已在关联数据集（https://doi.org/10.25581/spruce.049/1426474）中予以说明。SPRUCE实验设于美国明尼苏达州北部格兰德拉皮兹以北40公里处的8.1公顷S1泥炭沼泽林样地，隶属于美国农业部林务局（USDA Forest Service）马塞尔实验林（Marcell Experimental Forest, MEF）。