查看更多>>摘要：This special issue is a partial compilation of research papers from the 10th International Conference on Acid Deposition “ACID RAIN 2020” conference held in Niigata, Japan in April 2023, focusing on ecosystem responses to air pollution. The Acid Rain Conference series began in 1975, initially addressing the harmful effects of acid deposition on ecosystems. Over time, the research focus evolved from simple acid rain issues to effects of excess nitrogen deposition and saturation in the 1980s, and then to ecosystem recovery studies in the 1990s. Current research examines interactions with climate change and air pollution in developing countries. The special issue contains 11 papers: eight on long-term ecosystem responses, two on plants' role in reducing air pollution, and one technical note on soil sampling in biogeochemical monitoring. The long-term studies, from Japan and Norway, show different regional responses to acid deposition. Japanese forests demonstrate higher acid buffering capacity than Northern European ones, partly due to the composition of volcanic soil. Nordic papers focus on modeling tools, MAGIC (Model of Acidification of Groundwater In Catchments), which has been improved over time to simulate the combined effect of acid deposition and climate change impacts. It is significant that exactly half a century after the first conference, this collection of contemporary papers will be published in Ecological Research. This is because findings from research on biogeochemical cycles in ecosystems related to acid rain should be widely shared among the ecological community, and through this, a variety of audiences should be informed.
查看更多>>摘要：Although the amount of acidic deposition has recently decreased in Japan, it has still deteriorated some forest ecosystems during the past several decades. Moreover, recent climate changes can affect stream water chemistry. We investigated the temporal trend and effects of climate conditions on stream water chemistry for more than 20 years in two areas (Yusuhara and Taisho) in the Shmanto River Basin, southern Japan, where the effects of acidic deposition are considered to be modest. Stream water samples were collected monthly from three forest watersheds selected at each site. The annual means of the stream chemistry were predicted by multiple regression analysis. The ammonium, nitrate, and sulfate concentrations in the bulk precipitation have decreased at Yusuhara, and the sodium, magnesium, calcium, chloride, nitrate, and sulfate concentrations in the stream water have decreased in both areas. The nitrate and sulfate concentrations apparently responded to the decreasing input of acidic deposition. The sunlight hours were positively related with the potassium, magnesium, calcium, nitrate, sulfate, and bicarbonate concentrations in stream water. The results suggest that long sunlight hours boost the photosynthetic activities, thus promoting soil respiration and decomposition of soil organic matter. Moreover, a higher carbonic acid concentration in the soil solution promotes cation weathering and carbonic acid dissociation to bicarbonate. Given the decreasing trends in magnesium and calcium concentration with no change in bicarbonate concentration, we inferred that previousinputs of acidic deposition enhanced the rate of rock weathering.
查看更多>>摘要：Concerns have been raised regarding the degradation of stream water quality due to the excessive influx of atmospheric deposition. This study aimed to reveal the long-term variation in stream water chemistry in approximately 40 forested small watersheds in the northern Kanto region, based on 3 surveys conducted in 1991–1992, 2006–2007, and 2022. The factors influencing each dissolved element were investigated. Regarding longterm variations in stream water chemistry, relatively stable concentrations of cations (Ca~(2+), Mg~(2+), K~+, and Na~+) and SiO2were observed. However, the concentrations of anions (Cl~-, NO_3~- , and SO_4~(2-) ) decreased due to the improvement in the atmospheric environment and the diminishing effect of fertilization. Furthermore, the recent increase in stream water pH was attributed to an increase in bicarbonate (HCO_3~-), compensating for the decrease in anion concentrations relative to cations. Geology was the most significant factor for inter-watershed variations in cations and SiO_2, and this influence remained relatively constant over 30 years. Forest practices, especially fertilization, had a significant effect on Cl~- and NO_3~- , and contributed to higher concentrations in the fertilized watersheds than in the non-fertilized watersheds over the 15 years following fertilization. Sulfate deposition was a significant influencing factor for SO_4~(2-), and the concentration fluctuated under long-term variations in deposition over the past 30 years. Despite substantial acid deposition in the study area, the absence of stream water acidification could be attributed to the abundant cation supply from bedrock and volcanic ash, which underwent weathering processes.
Soyoka MakinoNaoko TokuchiDaisuke AkaishiLina A. Koyama...
277-292页
查看更多>>摘要：Mountain streamwater chemistry is an effective indicator of forest condition. In 2022, we conducted a nationwide investigation of mountain streamwater chemistry in Japan, leveraging citizen-participatory sampling. This approach involved 629 individuals with regular exposure to mountain and natural environments. Although our primary aim was to sample at locations from a 2003 study, we also welcomed samples from new sites. In total, 1414 streamwater samples were collected one time from each forested watershed at the baseflow condition. Our study focused on stream nitrate (NO_3~-) concentration as a key indicator of anthropogenic nitrogen (N) loading impacts on forests. We compared NO_3~- concentrations in 2022 with those from 2003 at identical sampling points. After excluding 179 points with evident human-created features upstream, the mean NO_3~- concentration in 2022 was 0.328 mg N L~(-1) (n = 1236). Comparing data from 1088 points sampled in both years, the mean value in 2022 (0.324 mg N L~(-1)) was significantly lower than that in 2003 (0.359 mg N L~(-1), p < 0.05). Notably, 88.5% of sampling points showed differences within ±0.25 mg N L~(-1). The spatial distribution pattern of mountain stream NO_3~- concentrations in 2022 did not consistently align with large cities, industrial areas, or N deposition sources. This unique approach marked the first nationwide participatory survey for collecting mountain streamwater in Japan. Our success in ensuring sample quality through accessible explanations, manuals, and videos demonstrates the potential of citizen science. However, the quantitative evaluation of scientific accuracy remains a forthcoming challenge.
查看更多>>摘要：The debate over whether forests around the Tokyo metropolitan area are nitrogen (N) saturation persists, as atmospheric N deposition in throughfall has decreased. This decrease is evidenced by a notable decline in samples collected in the 1990s (especially 1991–1992 and 1995). This decline can be attributed to a reduction in nitrogen oxide (NO_x) emissions from automobiles. The acidity derived from N deposition can increase aluminum (Al) mobility. We conducted a monitoring study from September 2010 to December 2021 to elucidate the effects of decreased N deposition on Al concentrations and flux in a forested Andisol. Throughfall and soil-percolated water samples were collected under stands of Japanese cedar and Japanese cypress in Hachioji, Tokyo (Field Museum Tamakyuryo). Major inorganic ions were determined by ion chromatography. Total Al concentrations were determined using atomic absorption spectrometry after concentration under acidic conditions. Aluminum and nitrate (NO_3~-) concentrations were significantly correlated in the both Japanese cedar and Japanese cypress stands. In the case of the Japanese cedar stand, Al concentrations tended to decrease over time from November 2010 to May 2015. Based on stepwise multiple regression analysis, acid load associated with N transformation ([H~+]_(load)) was chosen as the sole factor affecting Al mobilization in the Japanese cedar stand. Decreased N deposition affects Al dynamics via a decrease in [H~+]_(load).
查看更多>>摘要：For 40 years, Model of Acidification of Groundwater In Catchments (MAGIC) has been used to simulate the acidification of soils and waters due to acid deposition. The original model (MAGIC v8) has now been updated and reimplemented in the C++ Mobius platform and is available as open source. MAGIC-Forest includes new modules describing hydrology, forest growth, and soil carbon. The Mobius platform facilitates automatic optimization of calibrated parameters and multipoint calibrations using Monte-Carlo routines. The usefulness of MAGIC is demonstrated here by application to the 50-year data series for deposition and runoff at Birkenes, a small, calibrated catchment in southern Norway. Acid deposition has declined dramatically at Birkenes since the peak in the 1970s. Sulfate is 90% lower. Stream water has recovered strongly. Decreased concentrations of sulfate have led to increased acid-neutralizing capacity, pH, and reduced concentrations of toxic aluminum. These changes are well-simulated by MAGIC. The sulfate control on organic carbon solubility added as part of MAGIC-Forest improves the simulations. The MAGIC-Forest modeling tool is now available for applications to scenarios of land-use and climate change.
查看更多>>摘要：Atmospheric particulate matter (PM) is the most inhaled hazardous air pollutant that can cause adverse health impacts. Plants can remove such contaminants and act as biological filters through phytoremediation. In this study, we screened 12 Australian native species (two deciduous trees, three evergreen shrubs, and seven evergreen trees) growing in three regions to determine their potential in accumulating leaf surface (_SPM) and in-wax PM (_WPM). Among the screened species, Lagunaria patersonia (139.22 μg cm~(-2)) was the most effective PM accumulator, followed by Ficus obliqua (131.02 μg cm~(-2)). L. patersonia is an Australian native tree with a dense crown that can efficiently trap PM due to air turbulence between its leaves and branches; broad leaves with a rough texture enhance the plant's ability to trap PM. On the contrary, morphological characteristics like evergreen leaves with hairy appendages may act as an efficient trap for PM in F. obliqua. Due to smoother leaves, the least effective species were F. rubignosa and Eucalyptus saligna. In addition to leaf shape, leaf structures and micromorphology influence PM accumulation. For instance, Pittosporum undulatum accumulated more PM due to its wrinkled and folded leaf structures despite a significantly lower waxes layer. The findings highlight the importance of planting efficient PM accumulator species to shield vulnerable areas from pollution and decrease human exposure to pollutants. The sink capacity of these species can be used in urban tree planning to combat air pollution and improve air quality.
查看更多>>摘要：Nowadays, people tend to spend more time indoor, especially in the home and office environment. Indoor air pollution such as CO_2 is prevalent in domestic rooms because it is emitted mostly from human metabolism and daily activities such as cooking. This study aims to examine the change of CO_2 concentration in the office of company providing logistic services located in Gresik (Indonesia) as a response to phytoremediation and evaluate the effectiveness of selected ornamental plants in controlling CO_2 level. The study employed two plants species namely Maranta leuconeura E. Morren and Epipremnum aureum (Linden & Andre) G. S. Bunting to be placed in the first floor whereas the similar rooms in second floor were used as a control (without plants). The CO_2 level in all rooms have previously been measured and compared to quality standard. The required quantity of each plant was calculated based on CO_2 pollution load, office dimension, and CO_2 removal rate of plants. The presence of plants did not reduce CO_2 levels in the studied offices. In none of the offices with plants CO_2 concentrations dropped to the recommended levels. However, the plants maintained relatively stable CO_2 concentrations, unlike offices without plants, where the concentrations fluctuated and single peaks of increased concentrations were recorded. Room characteristics, exposure to sunlight, placement location of plants, and other external factors may affect efficiency of indoor phytoremediation.
查看更多>>摘要：Excessive anthropogenic nitrogen fixation alters the nitrogen cycle and increases nitrogen deposition, leading to nitrogen saturation, which in turns leads to forest decline and nitrate leaching into stream waters. Kureha Hill in Toyama Prefecture, Japan, is considered to be in nitrogen saturation, since many streams have contained high concentrations of nitrate for more than 20 years. In this study, the latest status of nitrogen saturation was verified by comparing most recent data with 20 years observational data, focusing on various indicators of nitrogen saturation, such as stream water quality, nitrogen budget of the watershed, and soil nitrification and mineralization potential. Both the nitrogen deposition on the Hyakumakidani watershed on Kureha Hill and the amount of nitrate leaching to the stream tended to decrease. The reduction in nitrate leaching could be attributed to the reduction in nitrogen deposition and other factors, such as nitrogen pools in the soil. Despite the recent decline in nitrate concentration of the Hyakumakidani stream, the pH level has remained unchanged. This may be due to decreased concentrations of sulfate and acid neutralizing capacity (ANC). The C/N ratio of the soil ranged from 12 to 18 from 2000 to 2023, which was lower than the nitrogen saturation threshold of 25. The net nitrification rate and net mineralization rate showed no significant changes between 2002 and 2023, indicating that the potential to produce nitrate has been unchanged. Similar values in net nitrification and net nitrogen mineralization rates reflected that the Hyakumakidani watershed remained in Stage-3 nitrogen saturation.
Heleen A. de WitFrancois ClayerOyvind KasteMagnus Norling...
352-364页
查看更多>>摘要：Five decades of monitoring data (1974–2022) at the acidified forested catchment of Langtjern in southern Norway document strong chemical recovery and browning of surface water, related to changes in sulfur (S) deposition. Further recovery is likely to be impacted by future air quality and climate, through catchment processes sensitive to climate change, where the relative importance of these drivers of recovery is poorly known. Here, we explore the importance of the aforementioned drivers for recovery using the wellestablished process-oriented Model of Acidification of Groundwater In Catchments (MAGIC) with historical and projected deposition and climate from 1860 to 2100. New in MAGIC are (ⅰ) a solubility control of dissolved organic carbon (DOC) from S deposition, which allows inclusion of the role of organic acids in chemical recovery and (ⅱ) climate-dependency of weathering rates. MAGIC successfully described observed chemical recovery and browning, and the change toward organic acid dominated acidification status. Hindcasts of pH predicted lower preindustrial pH than previously modeled with MAGIC (simulated without S-dependency of DOC solubility). Future deposition resulted in limited further recovery. Climate scenarios indicated a substantially wetter future, leading to increased base cation losses and slight surface water reacidification. A sensitivity analysis revealed that a 25%–50% increase of weathering rates was needed to reach preindustrial acid-neutralizing capacity in 2100, provided S deposition is reduced to a minimum. We predict that the limited chemical recovery from reduced S deposition will be counteracted by climate-driven reacidification from base cation losses, but that enhanced weathering rates could partly compensate these losses.
NETL
NSTL