Characterization of photosynthetic epilithic biomass on the river bed of the Upper Clark Fork River (Montana, USA) during the algal growing season of 2019

The Upper Clark Fork River (UCFR) Long Term Research in Environmental Biology (LTREB) umbrella monitoring project generating these data is conducted separately and complementarily to the 200-million-dollar (USD) superfund project for ecological restoration of the UCFR, associated tributaries, and head water streams including Silver Bow and Warm Springs Creeks. Restoration along the UCFR in western Montana includes removal of metal-laden floodplain soils, lowering of the floodplain to its original elevation, and re-vegetation of over 70 km of the river’s floodplain closest to contaminant sources. The UCFR LTREB project includes bi-weekly water quality monitoring across the first 200 km of the river and its major tributaries along a gradient of heavy metal contamination associated with historic mining. Monitoring includes inorganic phosphorus and nitrogen concentrations, biotic standing stocks, and dissolved and whole-water heavy metal concentrations. The monitoring program began in 2017 with funding likely to be extended through 2028. The original analytical intent for data in this product was to assess the response of the river algal community to the floodplain restoration. Data characterize epilithic biomass on the river bed including measurements of benthic standing stocks as organic matter and abundance of pigments associated with primary producers. Metrics of characterization include areal density of chlorophyll a, areal density of phaeophytin, the ratio of carotenoid to chlorophyll absorbance, areal density of organic matter, percent organic matter, and category of biomass composition (filamentous algae vs. other epilithon). Samples were obtained from collecting and scrubbing five rocks at any given site. Estimates of organic matter in biomass were obtained from area-corrected ash-free dry mass. Pigment concentrations were obtained through the use of extraction in acetone followed by spectroscopy. Data are from the 2019 algal growing season. Data were collected on the UCFR (USGS HUC 17010201) at seven project sites distributed along the river from the vicinity of Anaconda to Missoula, Montana, USA.

产生本数据集的上克拉克福克河（Upper Clark Fork River, UCFR）环境生物学长期研究（Long Term Research in Environmental Biology, LTREB）综合监测项目，独立开展且与耗资2亿美元（美元）的上克拉克福克河及其相关支流、包括银鲍溪（Silver Bow Creek）与暖泉溪（Warm Springs Creeks）在内的源头溪流生态修复超级基金项目形成互补。蒙大拿州西部的上克拉克福克河沿岸修复工程涵盖移除富含重金属的河漫滩土壤、将河漫滩恢复至原始高程，以及对距离污染源最近的70余公里河道河漫滩开展植被重建工作。上克拉克福克河环境生物学长期研究项目对河道前200公里及主要支流开展每两周一次的水质监测，监测区域覆盖与历史采矿活动相关的重金属污染梯度带。监测指标包括无机磷、氮浓度，生物现存量，以及溶解态与全水体重金属浓度。该监测项目于2017年启动，资助期限有望延长至2028年。本数据集的原始分析目标为评估河道藻类群落对河漫滩修复工程的响应。数据集表征了河床石生生物量，包含作为有机质的底栖生物现存量测量结果，以及与初级生产者相关的色素丰度。其表征指标包括叶绿素a面密度、褐藻素（phaeophytin）面密度、类胡萝卜素与叶绿素吸光度比值、有机质面密度、有机质占比，以及生物量组成类别（丝状藻类与其他石附生物（epilithon））。样本采集方式为在每个监测点位收集并刷洗五块岩石。生物量中有机质的估算值通过经面积校正的无灰干重法获得；色素浓度则通过丙酮萃取后进行光谱分析测得。本数据集取自2019年藻类生长季，数据采集于美国蒙大拿州上克拉克福克河（USGS HUC 17010201）沿线7个监测点位，分布范围从阿纳康达附近延伸至米苏拉。