Determining critical periods for thermal acclimatisation using a Distributed Lag Non-linear Modelling approach

Rapid changes in thermal environments are threatening many species worldwide. Thermal acclimatisation processes may partially buffer species from the impacts of these changes, but currently the knowledge about the temporal dynamics of acclimatisation remains limited. Acclimatisation phenotypes are typically determined in laboratory conditions that lack the variability and stochasticity that characterize the natural environment. Through a Distributed Lag Non-linear Model (DLNM), we use field data to assess how the timing and magnitude of past thermal exposures influence thermal tolerance. We apply the model to two Scottish freshwater Ephemeroptera species living in natural thermal conditions. Model results provide evidence that rapid heat hardening effects are dramatic and reflect high rates of change in temperatures experienced over recent hours to days. In contrast, temperature change magnitude impacted acclimatisation over the course of weeks but had no impact on short term responses...., The data are a collection of Serratella ignita and Baetis rhodani Critical Thermal maxima (CTmax) values. 
S. ignita (Poda 1761) and B. rhodani (Pictet 1843) are common and ubiquitous freshwater invertebrates across Europe. Both species usually produce a single generation per year, with eggs overwintering (hatching: ~March/April) and adults emerging from April to September, depending on local thermal conditions (see, López-Rodríguez et al., 2009; Raddum & Fjellheim, 1993) with non-overlapping generations in Scotland (Maitland, 1965; Morgan & Egglishaw, 1965).  Larvae of both species were collected from four sites in Scotland, in rivers upstream and downstream from two natural lakes (Rescobie Loch and Loch Morie) and two artificial reservoirs created by damming (Loch of Lintrathen and Glenquey Reservoir), giving a total of 8 sampling locations . Larval sampling took place within a circle of 5 m radius from the loggers, and within the same riffle, using kick sampling. Subsequent l..., , # Data from: Determining critical periods for thermal acclimatisation using a Distributed Lag Non-linear Modelling approach

## Description of the data and file structure

We include here the three data sets on which the analysis has been performed. 

1. \"allCT\" dataset contains all the Critical Thermal maxima value for samples of Serratella ignita and Baetis rhodani. Refer to the data description and the main manuscript for detailed information on the sampling method and CTmax estimation. The data set reports: \"date\" (sampling date); \"nsampl\" (progressive number of sampling location-specific); \"site\" (site of sampling, respectively Loch of Linthrathen, Loch Morie, Loch Rescobie and Glenquei reservoir); \"location\" (upstream or downstream sampling location); CTmax (Critical Thermal maxima in °C); size (larvae body size in cm); \"sp\" (species, respectively \"si\" for Serratella ignita, \"br\" for Baetis rhodani). is a freeform section for you to describe how the data are structured and how a ...

全球范围内热环境的快速变化正威胁着诸多物种的生存。热驯化（thermal acclimatisation）过程可在一定程度上为物种缓冲此类变化带来的冲击，但目前学界关于驯化过程的时间动态的认知仍较为匮乏。当前驯化表型的测定多在实验室条件下开展，而这类环境缺少自然环境所特有的变异性与随机性。本研究借助分布滞后非线性模型（Distributed Lag Non-linear Model, DLNM），利用野外实地数据，探究过往热暴露的时机与强度如何影响物种的热耐受能力。我们将该模型应用于苏格兰两种栖息于自然热环境的淡水蜉蝣目（Ephemeroptera）物种。模型结果显示，快速热硬化效应极为显著，反映出近数小时至数日内所经历的温度变化速率极高。与之相对，温度变化幅度则在数周尺度上对驯化过程产生影响，但并未对短期响应造成作用。

本数据集收录了 Serratella ignita 与 Baetis rhodani 的临界热最大值（Critical Thermal maxima, CTmax）实测值。
S. ignita（Poda 1761）与 B. rhodani（Pictet 1843）是欧洲境内常见且广布的淡水无脊椎动物。两类物种通常每年仅完成一个世代，以卵态越冬（孵化期约为3月/4月），成虫羽化期为4月至9月，具体时间取决于当地热环境条件（详见López-Rodríguez等，2009；Raddum & Fjellheim，1993），且在苏格兰地区种群世代不存在重叠（Maitland，1965；Morgan & Egglishaw，1965）。
研究人员从苏格兰的8个采样点位采集了两类物种的幼虫：覆盖两座天然湖泊（雷斯科比湖（Rescobie Loch）与莫里湖（Loch Morie））的上下游河段，以及两座筑坝形成的人工水库（林特拉亨湖（Loch of Lintrathen）与格伦奎水库（Glenquey Reservoir））。幼虫采样采用踢网采样法，采样范围限定为距温度记录仪5米半径内的同一急流区域。后续实验内容……

本数据集源自论文《使用分布滞后非线性建模方法确定热驯化的关键时期》（Determining critical periods for thermal acclimatisation using a Distributed Lag Non-linear Modelling approach）

#### 数据与文件结构说明
本次分析所使用的三份数据集均包含于此：
1. "allCT" 数据集：收录了所有 Serratella ignita 与 Baetis rhodani 样本的临界热最大值实测值。关于采样方法与CTmax测定流程的详细信息，请参阅数据说明文档与主论文。该数据集包含以下字段：
- "date"：采样日期
- "nsampl"：采样点位专属的渐进编号
- "site"：采样点位名称，分别为林特拉亨湖、莫里湖、雷斯科比湖与格伦奎水库
- "location"：采样点位位于河道上游或下游
- CTmax：临界热最大值，单位为摄氏度（°C）
- "size"：幼虫体长，单位为厘米（cm）
- "sp"：物种标识，其中"si"代表 Serratella ignita，"br"代表 Baetis rhodani。本段落为自由描述区域，用于说明数据的结构与相关内容……