Dataset from a study of aquatic macrophyte phenology across three sites in the Coeur d'Alene Lake Basin.

This repository includes data on aquatic macrophytes, water temperature, water clarity, and other water quality measures, such as pH, dissolved oxygen, and specific conductance relative to understanding the growth cycle (i.e., phenology) of aquatic plants. The data was generated during a project to study the phenology of macrophytes across the growing season of 2017, in three temperate lakes of the Coeur d’Alene Basin, USA. The project’s aim was to demarcate the timing of initial macrophyte growth, peak biomass, and senescence. The project also sought to compare traditional biomass measures with sonar biovolume (percent water column occupied by vegetation), which is relatively easier to collect. Macrophytes were measured twice per month with biomass collection via rake twirl, sonar biovolume, and species identification. Hourly water temperatures were measured over the course of the growing season at each site in shallow water near the macrophyte collection sites. The hourly water temperature data was used to calculate cumulative growing degree days over the growing season using minimum and maximum growth thresholds for Myriophyllum spicatum. Water temperature was also measured with a multi-parameter sonde at 0.5 meter increments from the water surface to the lake sediment and collected twice per month. Photosynthetically active radiation was measured during these vertical profiles and light extinction was calculated from this data. Water clarity was also measured with a standard black and white 20 centimeter Secchi disk. The data in this repository was originally reported in the following publication: Torso, K., Scofield, B.D. and Chess, D.W., 2020. Variations in aquatic macrophyte phenology across three temperate lakes in the Coeur d’Alene Basin. Aquatic Botany, 162, p.103209. https://doi.org/10.1016/j.aquabot.2020.103209

本数据集存储库包含水生大型植物、水温、水透明度及其他水质指标（如pH值、溶解氧、比电导率）相关数据，用于解析水生植物的生长周期（即物候学（phenology））。本数据采集自2017年生长季期间的一项研究项目，该项目针对美国科达伦盆地（Coeur d’Alene Basin）的三座温带湖泊，探究大型水生植物的物候变化。该项目的核心目标为明确大型植物初始生长、生物量峰值及衰老的时间节点，同时对比传统生物量测量方法与声呐生物量（sonar biovolume，即植被占据的水柱百分比）——后者的野外采集工作相对更为简便。研究团队每月对大型水生植物开展两次采样，通过耙子旋转法采集生物量、使用声呐获取生物量数据并完成物种鉴定。在每个采样点的水生植物采集区域附近浅水区，研究人员持续记录每小时水温数据，并基于穗状狐尾藻（Myriophyllum spicatum）的最低与最高生长阈值，计算生长季内的累计生长度日数。此外，团队还使用多参数水质探头（multi-parameter sonde），从水面至湖底沉积物以0.5米为间隔分层测量水温，每月采样两次；并在该垂直剖面测量过程中记录光合有效辐射（photosynthetically active radiation），进而据此计算光消光系数。同时，研究采用标准20厘米黑白赛氏盘（Secchi disk）测量水透明度。本仓库收录的数据最初发表于以下学术论文：Torso, K.、Scofield, B.D. 与 Chess, D.W., 2020. 《科达伦盆地三座温带湖泊中水生大型植物物候的变异》，《水生植物学》（Aquatic Botany），第162卷，第103209页。https://doi.org/10.1016/j.aquabot.2020.103209