MCR LTER: Coral Reef: Macroalgal CHN, ongoing since 2005

Samples of two common macroalgal species (Sargassum mangarevense, Turbinaria ornata) are collected yearly from fringing, backreef, and reef crest sites at each of the sites (LTER 1 through LTER 6) around Moorea. CHN analyses of dried, ground samples of each individual are made using standard methods. CHN data are used to track sustained variation in nutrient availability. Water column nutrients in coral reef systems usually are low to undetectable and their inputs tend to be episodic and ephemeral. Using CHN contents of macroalgae allows the integration of nitrogen availability over a longer time period, in this case, over approximately 3 months. This material is based upon work supported by the U.S. National Science Foundation under Grant No. OCE 22-24354 (and earlier awards) as well as a generous gift from the Gordon and Betty Moore Foundation. Research was completed under permits issued by the French Polynesian Government (Délégation à la Recherche) and the Haut-commissariat de la République en Polynésie Francaise (DTRT) (Protocole d'Accueil 2005-2023). This work represents a contribution of the Moorea Coral Reef (MCR) LTER Site.

研究人员每年从莫雷阿岛周边的6个长期生态研究（Long Term Ecological Research, LTER）站点（编号LTER 1至LTER 6）的岸礁、礁后与礁顶区域，采集两种常见大型藻类——马尾藻（Sargassum mangarevense）和团扇藻（Turbinaria ornata）的样本。采用标准方法对每份经干燥、研磨处理的单个藻类样本进行碳、氢、氮（Carbon, Hydrogen, Nitrogen, CHN）元素分析。上述碳氢氮元素分析数据被用于追踪营养盐可获得性的持续性变化。珊瑚礁生态系统的水体营养盐浓度通常极低甚至难以检出，且其输入过程多为突发性、临时性的。借助大型藻类的碳氢氮含量，可以整合更长时间尺度的氮素可获得性信息，在本研究中该时间跨度约为3个月。本数据集的研究工作得到了美国国家科学基金会（U.S. National Science Foundation）项目编号OCE 22-24354（及此前资助项目）以及戈登和贝蒂·摩尔基金会（Gordon and Betty Moore Foundation）的慷慨资助。本研究的开展已获得法属波利尼西亚政府研究代表团（Délégation à la Recherche）以及法兰西共和国驻法属波利尼西亚高级专员公署（DTRT）签发的相关许可，依据2005-2023年接待议定书（Protocole d'Accueil 2005-2023）。本研究系莫雷阿珊瑚礁（Moorea Coral Reef, MCR）长期生态研究站点的正式贡献成果。