Organic components of decomposing hardwood boles at the Hubbard Brook Experimental Forest, 1990-2016

In 1990-1991 segments of boles from felled sugar maple (Acer
saccharum), yellow birch (Betula alleghaniensis) and American beech
(Fagus grandifolia) trees were placed in the field to study the rate
of decomposition and nutrient loss (or gain) over time. The segments
incubated in the field, ranging from 0.5-1.3 meters in length, were
paired with fresh segments from the same trees. The fresh segments
were taken to the lab shortly after felling, dried, weighed and
subsampled. Fresh samples of wood and bark were collected separately.
Incubated bole segments were collected in 1993 (T1), 1997 (T2), 2001
(T3), 2007 (T4) and 2015/2016 (T5). The whole bole segments were
transported to the lab, measured, dried and weighed to determine mass
loss. Subsamples of the bole wood and bark were collected for chemical
analysis, including cross-polarization with magic-angle spinning
(CPMAS) 13C NMR. Chemical analyses were conducted concurrently on the
fresh (T0) and incubated samples. This data package includes the
unprocessed NMR data, phased spectra, and integrated (spectral area)
data in chemical shift regions that correspond to key structural
groups. This data set includes data for T1, T3, T4, and T5 samples and
their paired T0 fresh samples. Samples from T2 were measured for mass,
but inadvertently discarded prior to chemical analysis. These data were gathered as part of the Hubbard Brook Ecosystem Study
(HBES). The HBES is a collaborative effort at the Hubbard Brook
Experimental Forest, which is operated and maintained by the USDA
Forest Service, Northern Research Station.

1990至1991年间，研究人员将伐倒的糖枫（Acer saccharum）、黄桦（Betula alleghaniensis）和美山毛榉（Fagus grandifolia）的树干切段置于野外，以探究其随时间推移的分解速率与养分流失（或累积）规律。野外培养的树干切段长度介于0.5至1.3米之间，均与取自同一植株的新鲜切段配对。新鲜切段在伐倒后即刻被运送至实验室，经干燥、称重后完成分样。木材与树皮的新鲜样本分别采集。
野外培养的树干切段分别于1993年（T1）、1997年（T2）、2001年（T3）、2007年（T4）及2015/2016年（T5）进行回收。完整的树干切段被带回实验室后，经测量、干燥与称重以计算质量损失率。随后采集树干木材与树皮的分样用于化学分析，其中包括魔角旋转交叉极化¹³C核磁共振（CPMAS ¹³C NMR）。化学分析同步针对新鲜样本（T0）与野外培养样本开展。
本数据包包含未处理的核磁共振原始数据、相位校正谱图，以及对应关键结构基团化学位移区域的积分（谱峰面积）数据。本数据集涵盖T1、T3、T4、T5样本及其配对的T0新鲜样本数据。T2样本仅完成了质量测量，却在化学分析前被意外丢弃。
本数据采集工作隶属于哈伯布鲁克生态系统研究（Hubbard Brook Ecosystem Study, HBES）项目。该项目依托哈伯布鲁克实验林场开展协同研究，该林场由美国农业部林务局（USDA Forest Service）北部研究站运营维护。