Growing Season D and 18O isotope data for a core from the center and moat of the BBC collapse scar: Bonanza Creek Experimental Forest Flood Plains

This data set contains D and 18O data for a core from the center and moat (0 and 6 m) of the BBC collapse scar. Two well-preserved cores from the center of the bog was collected in March 2003 with a gasoline-powered permafrost corer. Cores were stored frozen and sampled using a radial saw. The core was sampled every two cm for macrofossil, diatom analysis and chemistry. Oxygen isotope ratios in aquatic cellulose has been shown to be a reliable tracer of lakewater isotope ratios (Sauer et al., 2001). I predicted that ?D and ?18O signatures in Sphagnum leaves would respond to enrichment and depletion in the bog water over time, providing an independent line of evidence for diatom-inferred hydrologic change. All isotope samples were processed by the Alaska Stable Isotope Facility using a Thermo Finnigan TC EA and Deltaplus XL mass spectrometer (Thermo Electron Corporation, Bremen, Germany) in continuous flow mode. Data were reported relative to standard mean ocean water (SMOW). Instrument precision was 1.2 ? SE for ?D and 0.3 ? SE for ?18O. I separated Sphagnum leaves from the bog and moat cores, and ran whole organic matter samples for ?D and ?18O stable isotopes. To determine the correlation between ?D and ?18O stable isotopes in peat leaves and bog water, I analyzed samples of Sphagnum and adjacent surface water. I collected surface water samples without headspace and refrigerated at 4 ?C until sample analysis. Snow samples were kept frozen until analysis. I refrigerated surface sample Sphagnum leaves from branches directly below the capitulum after harvest until analysis for ?D and ?18O stable isotopes. I identified Sphagnum samples to species. This data set was collected to relate ?D and ?18O to fires, changes in succession, changes in hydrology, and diatom assemblages.本数据集涵盖了取自BBC塌陷坑（BBC collapse scar）中心与壕沟（深度分别为0 m与6 m）处岩芯的氢同位素（D）与氧同位素（¹⁸O）数据。2003年3月，研究者使用汽油动力冻土取芯器（gasoline-powered permafrost corer）采集了两孔保存完好的沼泽中心岩芯。所有岩芯均以冷冻状态保存，并使用径向锯进行分样；每间隔2 cm采集一个子样，用于大化石分析、硅藻分析及化学组分检测。 水生纤维素中的氧同位素比值已被证实可作为湖水同位素比值的可靠示踪剂（Sauer等，2001）。本研究推测，泥炭藓（Sphagnum）叶片中的δD与δ¹⁸O信号会随时间响应沼泽水体的富集与耗竭过程，从而为基于硅藻反演的水文变化提供独立的证据链。 所有同位素样品均由阿拉斯加稳定同位素实验室（Alaska Stable Isotope Facility）采用连续流模式，通过德国不来梅赛默飞世尔科技公司（Thermo Electron Corporation）生产的Thermo Finnigan TC EA元素分析仪与Deltaplus XL质谱仪完成前处理与测试。所有同位素数据均以标准海洋水（SMOW，standard mean ocean water）为基准进行报告。仪器分析精度为：δD的标准误为±1.2‰，δ¹⁸O的标准误为±0.3‰。本研究从沼泽与壕沟岩芯中分离出泥炭藓叶片，并对全有机质样品开展δD与δ¹⁸O稳定同位素检测。 为明确泥炭叶片与沼泽水中δD、δ¹⁸O稳定同位素的相关性，本研究对泥炭藓样品及邻近地表水样品开展了分析。地表水样品采集时无顶空（headspace），采集后于4℃冷藏直至检测。雪样则全程冷冻保存至检测环节。采集后，本研究将取自头状花序（capitulum）下方枝条的地表泥炭藓叶片样品冷藏，直至开展δD与δ¹⁸O稳定同位素分析；本研究对所有泥炭藓样品进行了物种鉴定。 本数据集的采集目的在于建立δD、δ¹⁸O与火灾事件、群落演替变化、水文变化及硅藻组合之间的关联。