MCR LTER: Coral Reef: Long-term Community Dynamics: Backreef (Lagoon) Corals Annual Survey, ongoing since 2005

This dataset contains the percentage cover of all stony corals (Scleractinia, pooled among genera) and other major groups analyzed from 0.5 x 0.5 m photographic quadrats at the Backreef habitat at the Moorea Coral Reef LTER, French Polynesia. This survey time series began in 2005 and is repeated each year in April. Functional groups counted are: Scleractinian corals, Macroalgae, Crustose Coralline Algae / Bare Space, Soft Corals, Hydrocorals ( Millepora
), Algal Turf and Sand. The coral community was sampled photographically in all represented habitats surrounding the island: Fringing Reef, Lagoon, and Outer Reef. This dataset contains only Lagoon (Backreef) data (see knb-lter-mcr.4 for the other habitats) and is structured in a repeated-measures protocol to allow a statistical contrast of sites, shores and times. Community structure was determined through a coarse analysis of the benthic community, initially completed in situ (2005), but using photoquadrats from 2006. There are quadrats analyzed at each of five areas within each site, and the areas are revisited (but not the quadrats) each year to support the repeated measures design. There are two tables available, providing different views of the same data: a long table having all values in one column and a wide table having a separate column for each observed object. Detailed methods are available in the protocols section.

本数据集包含法属波利尼西亚莫雷阿珊瑚礁长期生态研究站点（Moorea Coral Reef LTER）后礁生境中，基于0.5×0.5米摄影样方（photographic quadrats）统计得到的所有石珊瑚（Scleractinia，按属合并）及其他主要类群的盖度百分比。本调查时间序列始于2005年，每年4月重复开展一次调查。本次统计的功能群包括：石珊瑚、大型藻类（Macroalgae）、壳状珊瑚藻/裸露空间（Crustose Coralline Algae / Bare Space）、软珊瑚、水螅珊瑚（Hydrocorals, Millepora属）、藻席（Algal Turf）以及沙质沉积物（Sand）。该岛屿周边所有典型生境中的珊瑚群落均通过摄影方式采样，生境类型包括岸礁（Fringing Reef）、泻湖（Lagoon）与外礁（Outer Reef）。本数据集仅包含泻湖（后礁）相关数据（其他生境数据详见knb-lter-mcr.4），并采用重复测量实验设计（repeated-measures protocol），以支持对样点、岸线与时间的统计对比分析。底栖群落结构通过粗分辨率底栖群落分析确定：2005年的初始分析为原位完成，2006年起则改用摄影样方开展分析。每个样点内设5个区域，每年仅对这些区域进行重访（而非原有样方），以契合重复测量的实验设计。本数据集提供两张数据表，以不同形式呈现同一套数据：一张为长格式数据表，所有观测值汇总于单一列中；另一张为宽格式数据表，每类观测对象对应单独一列。详细实验方法可参见数据集的实验方案部分。