Determination of mean effective shore level to delineate periods of emersion and immersion for intertidal rocky shores

This dataset contains data described in the paper entitled \"Environmental filtering causes increasingly negative effects towards the range limit of an invasive mussel\". Data include: the R script to estimate temperature thresholds and calculate effective shore levels (esl_function.R); data files associated with this R script (material.RData); mean effective shore levels determined for the five South African rocky-shore sites where submersible temperature data loggers were installed (esl_overall_results.csv); measurements of mussel shell lengths, level of endolithic infestation, and counts of epibionts on the basibiont mussel Mytilus galloprovincialis (mussel_data.csv); counts of barnacles (Chthamalus dentatus) and mussels (Mytilus galloprovincialis and Perna perna) on emersed rocks using 50 × 50 cm quadrats and counts of mussels (Mytilus galloprovincialis and Perna perna) in mono-layer mixed-species mussel patches using 25 × 25 cm quadrats (quadrat_data.csv); hourly temperatures recorde..., , The readme file provides a description of each column in the dataset. NA =  values not available.

本数据集包含发表于题为《环境过滤对入侵贻贝分布边界产生愈发显著的负面影响》的论文中的相关数据，具体如下：
1. 用于估算温度阈值并计算有效潮间带高度（effective shore levels）的R脚本（esl_function.R）；
2. 与该R脚本配套的数据文件（material.RData）；
3. 针对安装了水下温度数据记录器（submersible temperature data loggers）的5个南非岩岸站点所测算得到的平均有效潮间带高度数据（esl_overall_results.csv）；
4. 基底宿主紫贻贝（Mytilus galloprovincialis）上的贻贝壳长测量值、贝壳石内寄生侵染程度以及附生生物数量数据（mussel_data.csv）；
5. 采用50×50厘米样方对干出岩石上的齿额纹藤壶（Chthamalus dentatus）以及紫贻贝（Mytilus galloprovincialis）和偏顶蛤（Perna perna）的数量统计数据，同时包含采用25×25厘米样方对单层混合物种种贻贝斑块内的紫贻贝（Mytilus galloprovincialis）和偏顶蛤（Perna perna）的数量统计数据（quadrat_data.csv）；
6. 每小时温度记录数据（原文此处内容存在截断）；
本数据集的自述文件（readme file）对数据集中各列的含义进行了详细说明。NA表示缺失值（values not available）。