Paleoecological investigations of recent lake acidification in northern Florida
TL;DR: In this article, a transfer function relating surface sediment diatom assemblages to lakewater pH (R2 = 0.89, s.e.t.=0.34) was presented.
Abstract: Thirty-two northern Florida lakes were analyzed to construct a transfer function relating surface sediment diatom assemblages to lakewater pH (R2=0.89, s.e.=0.34). A paleoecological analysis of sediment cores from six of these lakes indicated that two have become more acidic in the last 50 years. The diatom inferred (DI) pH of L. Barco has declined between 0.56–0.82 in the 1900's and DI ANC (acid neutralizing capacity) by 28–46 μeq l-1. The DI pH of nearby L. Suggs has declined 0.91 pH units and its DI ANC by 19 μeq l-1. The timing of the inferred acidification is synchronous with known increases in emissions of sulfates and nitrates that are associated with acidic precipitation. Also, the increasing accumulation of substances related to emissions from the burning of fossil fuels (e.g., Pb, PAH) co-occurs with the lowering of DI pH in the sedimentary record. However, other processes may have accounted for or contributed to recent lake acidification. For instance, the drawdown of local water tables by human consumption may decrease the inseepage of ANC to seepage lakes. Such an effect would be synchronous with increasing depositions of sulfate. There is also clear evidence that Florida lakes are naturally acidic. Thus, paleoecological results indicate acidic deposition to be at certain contributor, but not necessarily the sole cause, of the recent further acidification of some naturally acidic Florida lakes.
Citations
More filters
Book•
01 Jan 2002
TL;DR: The second edition of the Rosetta Stone has been published by as discussed by the authors, which is used to calibrate indicators to environmental variables using surface-sediment training sets, such as ozone depletion, acid rain, and climatic warming.
Abstract: Preface to the second edition. About the author. 1 There is no substitute for water. 2 How long is long?. 3 Sediments: an ecosystem's memory. 4 Retrieving the sedimentary archive and establishing the geochronological clock: collecting and dating sediment cores. 5 Reading the records stored in sediments: the present is a key to the past. 6 The paleolimnologist's Rosetta Stone: calibrating indicators to environmental variables using surface-sediment training sets. 7 Acidification: finding the "smoking gun". 8 Metals, technological development, and the environment. 9 Persistent organic pollutants: industrially synthesized chemicals "hopping" across the planet. 10 Mercury - "the metal that slipped away". 11 Eutrophication: the environmental consequences of over-fertilization. 12 Erosion: tracking the accelerated movement of material from land to water. 13 Species invasions, biomanipulations, and extirpations. 14 Greenhouse gas emissions and a changing atmosphere: tracking the effects of climatic change on water resources. 15 Ozone depletion, acid rain, and climatic warming: the problems of multiple stressors. 16 New problems, new challenges. 17 Paleolimnology: a window on the past, a key to our future. Glossary. References. Index
673 citations
Cites methods from "Paleoecological investigations of r..."
...In the PIRLA-I project, paleolimnologists used detailed analyses of short sediment cores in several acid-sensitive regions of the United States (i.e., Adirondack Park – Charles et al. 1990; northern New England – Davis et al. 1994; the Upper Midwest – Kingston et al. 1990; Florida – Sweets 1992; Sweets et al. 1990; and complementary work in the Sierra Nevada region – Whiting et al. 1989) to track changes in specific lakes....
[...]
TL;DR: This commentary uses the analogy of human health to argue that paleolimnological data provide information crucial to the decision-making processes of ecosystem managers.
Abstract: Effective management of aquatic resources requires long-term environmental data. However, because long-term observations are rarely available, indirect proxy methods must be used to substitute for these missing historical data sets. Major advances have been made in paleolimnology over the last decade, and many of these advances can be applied directly to integrated and cost-effective assessments of aquatic ecosystem health. This commentary uses the analogy of human health to argue that paleolimnological data provide information crucial to the decision-making processes of ecosystem managers.
289 citations
Cites background from "Paleoecological investigations of r..."
...Charles et al., 1990; Kingston, et al., 1990; Sweets et al., 1990 ) show that lakes in acid-sensitive regions receiving acidic precipitation have acidified (beyond their range of natural variability) and that these changes were correlated with known deposition patterns of strong, inorganic acids....
[...]
01 Jan 2010
TL;DR: The acidification of lakes became an environmental issue of international significance in the late 1960s and early 1970s when Scandinavian scientists claimed that acid rain was the principal reason why lakes acidified as mentioned in this paper.
Abstract: Lake acidification became an environmental issue of international significance in the late 1960s and early 1970s when Scandinavian scientists claimed that ‘acid rain’ was the principal reason why f ...
143 citations
01 Jan 1991
TL;DR: In this article, the authors present historical sulfur emission and deposition trends for regions in the United States and describe methods for assessing changes in water chemistry based on current spatial patterns, ion ratios and empirical models, and paleolimnological approaches.
Abstract: This chapter presents historical sulfur emission and deposition trends for regions in the United States and describes methods for assessing changes in water chemistry based on current spatial patterns, ion ratios and empirical models, and paleolimnological approaches. Reconstruction of sulfur deposition trends shows that current deposition to case study regions ranges from a factor of about 1 (Upper Midwest) to a factor of 10 (Catskills) above natural background. Deposition in the Northeast was high during the 1920s, 1940s, and 1960s, and has declined significantly since 1970. Sulfur deposition in the Southeast was low before the 1950s, but has increased significantly since then. Change in surface water chemistry can be assessed using simple empirical models, ion ratios, and analysis of current spatial patterns of chemistry. Many assumptions are implicit in these methods, so results should be interpreted carefully. Paleolimnological reconstructions of chemistry and biota from lake sediment records provide more direct evidence of past change than other approaches. Quantitative analyses of diatom and chrysophyte assemblages can be used to reconstruct past lakewater pH with a mean standard error of about ± 0.25 pH units.
129 citations
Cites background or methods from "Paleoecological investigations of r..."
...(1983) from 1978 to 1979, the ELS in 1984, and the PIRLA study in the Florida NortHern Peninsula (Sweets et al. 1990) in 1985....
[...]
...Twenty-seven of these lakes were resampled in 1985 and 1986 as part of the Paleolimnological Investigation of Recent Lake Acidification (PIRLA) project funded by the Electric Power Research Institute (EPRI) and the National Science Foundation (NSF) (Sweets et al. 1990)....
[...]
...sands characteristic of their watersheds (Sweets et al. 1990)....
[...]
...Paleolimnological analysis of changes in diatom assemblages in the sedimentary record of six lakes in north Florida has been used to infer recent historical change in pH and ANC as part of the PIRLA study (Sweets et al. 1990)....
[...]
TL;DR: A survey of lakes and streams in acid-sensitive areas of the United States, the National Surface Water Survey (NSWS), was used to identify the role of acidic deposition, relative to other factors, in causing acidic conditions in 1,181 lakes and 4,668 streams as mentioned in this paper.
Abstract: A statistically designed survey of lakes and streams in acid-sensitive areas of the United States, the National Surface Water Survey (NSWS), was used to identify the role of acidic deposition, relative to other factors, in causing acidic conditions in 1,181 lakes and 4,668 streams. Atmospheric deposition is the dominant source of acid anions in 75% of the acidic lakes and 47% of the acidic streams. Organic anions are dominant in one-fourth of the acidic lakes and streams; acidic mine drainage is the dominant acid source in 25% of the acidic streams. Other causes of acidic conditions are relatively unimportant on a regional scale. Nearly all the deposition-dominated acidic systems were found in six well-delineated subpopulations that represent about one-fourth of the NSWS lake population and one-third of the NSWS stream population.
118 citations
References
More filters
TL;DR: In this article, a new multivariate analysis technique, called canonical correspondence analysis (CCA), was developed to relate community composition to known variation in the environment, where ordination axes are chosen in the light of known environmental variables by imposing the extra restriction that the axes be linear combinations of environmental variables.
Abstract: A new multivariate analysis technique, developed to relate community composition to known variation in the environment, is described. The technique is an extension of correspondence analysis (reciprocal averaging), a popular ordination technique that extracts continuous axes of variation from species occurrence or abundance data. Such ordination axes are typically interpreted with the help of external knowledge and data on environmental variables; this two—step approach (ordination followed by environmental gradient identification) is termed indirect gradient analysis. In the new technique, called canonical correspondence analysis, ordination axes are chosen in the light of known environmental variables by imposing the extra restriction that the axes be linear combinations of environmental variables. In this way community variation can be directly related to environmental variation. The environmental variables may be quantitative or nominal. As many axes can be extracted as there are environmental variables. The method of detrending can be incorporated in the technique to remove arch effects. (Detrended) canonical correspondence analysis is an efficient ordination technique when species have bell—shaped response curves or surfaces with respect to environmental gradients, and is therefore more appropriate for analyzing data on community composition and environmental variables than canonical correlation analysis. The new technique leads to an ordination diagram in which points represent species and sites, and vectors represent environmental variables. Such a diagram shows the patterns of variation in community composition that can be explained best by the environmental variables and also visualizes approximately the "centers" of the species distributions along each of the environmental variables. Such diagrams effectively summarized relationships between community and environment for data sets on hunting spiders, dyke vegetation, and algae along a pollution gradient.
5,689 citations
TL;DR: Canonical correspondence analysis (CCA) is introduced as a multivariate extension of weighted averaging ordination, which is a simple method for arranging species along environmental variables.
Abstract: Canonical correspondence analysis (CCA) is introduced as a multivariate extension of weighted averaging ordination, which is a simple method for arranging species along environmental variables. CCA constructs those linear combinations of environmental variables, along which the distributions of the species are maximally separated. The eigenvalues produced by CCA measure this separation.
1,251 citations
TL;DR: Reconstruction of past lake-water pH from diatom data involves two steps; regression, where responses of modern diatom abundances to pH are modelled and calibration, where the modelled responses are used to infer pH fromdiatom assemblages preserved in lake sediments.
Abstract: Palaeolimnological diatom data comprise counts of many species expressed as percentages for each sample. Reconstruction of past lake-water pH from such data involves two steps; (i) regression, where responses of modern diatom abundances to pH are modelled and (ii) calibration where the modelled responses are used to infer pH from diatom assemblages preserved in lake sediments. In view of the highly multivariate nature of diatom data, the strongly nonlinear response of diatoms to pH, and the abundance of zero values in the data, a compromise between ecological realism and computational feasability is essential. The two numerical approaches used are (i) the computationally demanding but formal statistical approach of maximum likelihood (ML) Gaussian logit regression and calibration and (ii) the computationally straightforward but heuristic approach of weighted averaging (WA) regression and calibration. When the Surface Water Acidification Project (SWAP) modern training set of 178 lakes is reduced by data-screening to 167 lakes, WA gives superior results in terms of lowest root mean squared errors of prediction in cross-validation. Bootstrapping is also used to derive prediction errors, not only for the training set as a whole but also for individual pH reconstructions by WA for stratigraphic samples from Round Loch of Glenhead, southwest Scotland covering the last 10 000 years. These reconstructions are evaluated in terms of lack-of-fit to pH and analogue measures and are interpreted in terms of rate of change by using bootstrapping of the reconstructed pH time-series.
1,046 citations
TL;DR: A discussion of some of the processes that have contributed to the acidification of lakes as well as those that have protected acid-sensitive freshwaters is presented.
Abstract: Acid-vulnerable areas are more numerous and widespread than believed 7 years ago. Lakes and streams in acid-vulnerable areas of northeastern North America have suffered substantial declines in acid-neutralizing capacity, the worst cases resulting in biological damage. Many invertebrates are very sensitive to acidification, with some disappearing at pH values as high as 6.0. However, the recent rate of acidification of lakes is slower than once predicted, in part the result of decreases in sulfur oxide emissions. A discussion of some of the processes that have contributed to the acidification of lakes as well as those that have protected acid-sensitive freshwaters is presented. The author is in the Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba R3T 2N6, Canada.
641 citations
"Paleoecological investigations of r..." refers background in this paper
...Recent investigations measured the pH of precipitation in some remote areas to be about 5.0 from both weak and strong acids ( Schindler, 1988 )....
[...]
TL;DR: In this article, first-order error analysis and Monte Carlo simulation (of cores from Florida PIRLA lakes) are used as independent estimates of dating uncertainty, and confidence intervals for 210Pb dates are calculated.
Abstract: Lead-210 assay and dating are subject to several sources of error, including natural variation, the statistical nature of measuring radioactivity, and estimation of the supported fraction. These measurable errors are considered in calculating confidence intervals for 210Pb dates. Several sources of error, including the effect of blunders or misapplication of the mathematical model, are not included in the quantitative analysis. First-order error analysis and Monte Carlo simulation (of cores from Florida PIRLA lakes) are used as independent estimates of dating uncertainty. CRS-model dates average less than 1% older than Monte Carlo median dates, but the difference increases non-linearly with age to a maximum of 11% at 160 years. First-order errors increase exponentially with calculated CRS-model dates, with the largest 95% confidence interval in the bottommost datable section being 155±90 years, and the smallest being 128±8 years. Monte Carlo intervals also increase exponentially with age, but the largest 95% occurrence interval is 152±44 years. Confidence intervals calculated by first-order methods and ranges of Monte Carlo dates agree fairly well until the 210Pb date is about 130 years old. Older dates are unreliable because of this divergence. Ninety-five per cent confidence intervals range from about 1–2 years at 10 years of age, 10–20 at 100 years, and 8–90 at 150 years old.
607 citations
"Paleoecological investigations of r..." refers methods in this paper
...Error bars for 2]~ dates are standard deviations calculated by Binford (1990) ....
[...]
...The method, quality assurance procedures, error analyses, and results of 21~ dating for all PIRLA cores are described fully in Binford (1990) , Norton et al. (1990), and Binford et al. (in prep.)....
[...]