A Bibliometric Analysis of Research on Acid Rain

Abstract

With the continuation of industrialization and urbanization, acid rain (AR) has aroused extensive concern because of its potential negative effects on ecosystems. However, analysis of the current status and development trends in AR research area has seldom been systematically studied. Therefore, we motivated to conduct a bibliometric analysis of AR publications (1900–2018) using HistCite and CiteSpace software programs. Compared to traditional reviews by experts, this study offers an alternative method to quantitatively analyze and visualize the development of AR field at a large time scale. The results indicated that the overall concern of AR research studies had increased from 1900 to 2018. The most productive country was the United States, while the institution with the most publications was Chinese Academy of Sciences. “Environmental Sciences” was the most popular subject category, Water, Air, and Soil Pollution was the dominant journal, and C.T. Driscoll was the most prominent author in AR field. There were three hotspots in the field of AR, including analyzing AR status and its control policies in Europe, the United States, and China in the past few decades, investigating the ecological consequences of AR on plant histological, physiological, and biochemical traits, as well as surface water and soil properties, and the model application for quantitatively assessing AR and its effects on terrestrial and aquatic ecosystems at regional scale. Further, “behavior”, “phosphorus”, “fractionation”, “soil acidification”, “corrosion”, “performance”, “recovery”, “rainwater”, “trace element”, and “surface water” have been emerging active topics in recent years. This study can help new researchers to find out the most relevant subject categories, countries, institutions, journals, authors, and articles, and identify research trends and frontiers in the field of AR.

Long-Term Temporal Changes of Precipitation Quality in Slovak Mountain Forests

“…The results of many observations, especially in the northern hemisphere, point to significant changes in precipitation chemistry, especially in pH values, concentrations of sulfur, nitrogen, but also basic cations. Most notably, these changes are visible at pH values and sulfate concentrations in precipitation water [2,11,24,27,34,35].…”

“…Nitrates are involved in precipitation acidity to a lesser extent than sulfates [11,27]. With the measurement and determination of nitrate concentration in precipitation, Chopok began in October 1985 and Polana in 1993.…”

“…Within the last two decades a distinct decrease in emissions in Czech Republic, Slovakia, and Poland has been achieved due to improvement of heat and power production technology, implementation of measures aimed at reducing sulfur emissions from power stations that use brown coal, increased use of low-sulfur fuels in private households and emission control at national and European level [8,9]. Some studies show that precipitation containing a higher proportion of sulfates are more toxic than precipitation at the same pH level but containing a higher proportion of nitrates [10,11].…”

“…In Europe, nitrogen oxides (NOx-N) are emitted mainly from stationary combustion sources (power plants and industrial processes) and transportation sources (road, off-road, and ship traffic). NOx-N emissions increased in the 1980s due to increased traffic and started to decrease in the mid-1990s [2,11]. The road transport sector represents the largest source of NOx emissions, accounting for 39% of total EU-28 emissions in 2013 [1,11].…”

“…NOx-N emissions increased in the 1980s due to increased traffic and started to decrease in the mid-1990s [2,11]. The road transport sector represents the largest source of NOx emissions, accounting for 39% of total EU-28 emissions in 2013 [1,11].…”