Little Rock Lake Experiment at North Temperate Lakes LTER: pH and Alkalinity 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. pH and alkalinity of the
treatment and reference basins of Little Rock Lake are measured at one station in the
deepest part of each basin at the top and bottom of the epilimnion, mid-thermocline, and
top, middle, and bottom of the hypolimnion. During the course of the study, three different
types of electrodes were used to measure pH. Sampling Frequency: varies - Number of sites: 2

小石城酸化实验（Little Rock Acidification Experiment）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。小石城湖是坐落于美国威斯康星州维拉斯县的双叶状湖泊。1983年，该湖通过不透水帷幕被分割为两个湖盆；1984年至1989年间，研究团队分三个为期两年的阶段，以硫酸对湖北部湖盆实施酸化处理，三个阶段的目标pH值分别为：1984-1985年5.7、1986-1987年5.2、1988-1989年4.7。1990年起，尽管不透水帷幕仍保留原位，湖泊开始自然恢复。研究数据的采集工作持续至2000年。本项目的核心目标是解析全湖酸化对种群、群落及生态系统的影响。本项目由美国环境保护署（USEPA）与美国国家科学基金会（NSF）提供资助。研究人员在每个湖盆的最深点位设置监测站，分别在表水层（epilimnion）的上下层、温跃层中部以及湖下层（hypolimnion）的上、中、下层，测定处理组与对照组湖盆的pH值与碱度。本研究期间共使用过三种不同类型的pH电极。采样频率：不固定；监测点位数量：2个