Little Rock Lake Experiment at North Temperate Lakes LTER: Zooplankton count 1983 - 2000

The Little Rock Acidification Experiment was a joint project involving the USEPA (Duluth Lab), University of Minnesota-Twin Cities, University of Wisconsin-Superior, University of Wisconsin-Madison, and the Wisconsin Department of Natural Resources. Little Rock Lake is a bi-lobed lake in Vilas County, Wisconsin, USA. In 1983 the lake was divided in half by an impermeable curtain and from 1984-1989 the northern basin of the lake was acidified with sulfuric acid in three two-year stages. The target pHs for 1984-5, 1986-7, and 1988-9 were 5.7, 5.2, and 4.7, respectively. Starting in 1990 the lake was allowed to recover naturally with the curtain still in place. Data were collected through 2000. The main objective was to understand the population, community, and ecosystem responses to whole-lake acidification. Funding for this project was provided by the USEPA and NSF. Zooplankton samples are collected from the treatment and reference basins of Little Rock Lake at at two to nine depths using a 30L Schindler Patalas trap (53um mesh). Zooplankton samples are preserved in buffered formalin and archived. Data are summed over sex and stage and integrated volumetrically over the water column to provide a lake-wide estimate of organisms per liter for each species. Sampling Frequency: varies - Number of sites: 2

小石湖酸化实验是一项联合研究项目，参与方包括美国环境保护署（USEPA）德卢斯实验室、明尼苏达大学双城分校、威斯康星大学苏必利尔分校、威斯康星大学麦迪逊分校以及威斯康星州自然资源部。小石湖是坐落于美国威斯康星州维拉斯县的双叶状湖泊，1983年该湖被一道不透水帷幕分隔为两部分；1984年至1989年间，研究团队分三个两年阶段对湖北部盆地施加硫酸酸化处理，三个阶段（1984-1985年、1986-1987年、1988-1989年）的目标pH值分别为5.7、5.2和4.7。1990年起，在保留不透水帷幕的前提下，允许湖泊自然恢复，相关数据采集工作持续至2000年。本项目的核心目标是阐明种群、群落及生态系统对全湖酸化的响应机制，项目由美国环境保护署（USEPA）与美国国家科学基金会（NSF）资助。研究人员采用30L辛德勒-帕塔拉斯采样器（Schindler Patalas trap，53um网目），在处理组与参照组湖区的2至9个深度层采集浮游动物样本，样本经缓冲福尔马林固定后归档保存；实验数据按性别与发育阶段汇总，并在水柱中按体积积分，以此得到每升水体中各物种种群的全湖估计量。采样频率：不固定；采样点位数量：2个。