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1.
In addition to strong natural stresses forest ecosystems in the Kola Subarctic, Russia, receive high loads of sulphur and heavy metals from the nickel smelter. To estimate soil response to acid deposition we compared the soil field data along a pollution gradient and simulated time effects. Multivariate technique was applied to investigate spatial distribution of soil field data. Time response of soils to acid deposition was evaluated with the SMART model. According to field observations there is no evidence for strong soil acidification effects close to the smelter. Concentrations of exchangeable Ca and base saturation increase, while acidity decrease in lower soil mineral horizons towards the pollution source. However, some features seem to reflect the early stages of the started acidification. Most soil profiles have low pH values. Despite increasing of exchangeable Ca and Mg towards the smelter in lower mineral horizons due to geological inheritance, they do not reveal the same trends in the upper ones. Concentration of exchangeable K in organic horizons decreases towards the smelter, thus confirming the starting acidification. As result, exchangeable base cations are depleted in the considerable part of shallow soil profiles. According to model simulation the present acid load does not effect considerably on forest soils in background areas, however, dramatic shift in soil chemistry near the smelter is expected within several decades. Due to low pool of exchangeable base cations and low weathering rate continued acid deposition can lead to increased soil acidification and nutrient imbalance. 相似文献
2.
土壤风化速率研究及其应用 总被引：4，自引：1，他引：3
土壤矿物风化是土壤、也是整个生态系统中无机矿质养分的最重要来源,不仅为植物长期提供养分和保持土壤的化学平衡稳定性,并缓冲土壤和地表水的酸化,还影响全球气候变化。风化速率在全球碳循环、酸临界负荷和土壤侵蚀等研究中都是非常重要的参数。土壤化学风化是一个不断进行的自然释放过程,气候是最主要的驱动力,而矿物本身的稳定性也影响了风化速率的快慢。由于人为影响下的大气酸沉降和农业活动已经非常普遍,目前的土壤风化速率也因此而改变。本文从风化速率的研究方法、风化速率的影响因素以及风化速率在全球变化中的应用3个方面介绍了近年来在风化速率方面的研究进展,并探讨了相关研究未来的发展趋势。 相似文献
3.
Acidity budgets for an artificially acidified and an unacidified peatland in mid-continental North America are dominated by the production and export of organic acids. A fraction (about 50%) of these acids are neutralized by alkalinity from atmospheric deposition and upland run-off. The acid applied to the experimentally acidified site is neutralized by uptake of nitrate and sulfate. Short-term measurements show that nitrate is taken up rapidly in surface layers of moss while sulfate penetrates more deeply into the peat. Sulfate retention within the two sites ranges from 56 to 70% on an annual basis. Stripping of basic cations is shown to result from acid application to base-rich peat. These results suggest that short-term effects of acid deposition on peatlands will be slight, but long-term site acidification is possible. 相似文献
4.
The Simple Mass Balance (SMB) equation allows critical loadsto be calculated for forest soils such that all the processesresponsible for acidification and buffering are considered(i.e acidic deposition, deposition of base cations andchloride, mineral weathering, base cation uptake and removalat harvest, nitrogen immobilisation, uptake anddenitrification, and acidity leached). The equation is nowused by 11 UNECE countries in mapping forest critical loadsfor consideration under the Convention on Long RangeTransboundary Air Pollution. In the work described here wehave put together suitable stemwood and bark nutrientconcentrations from the literature with new measurements inorder to calculate species' specific base cation removalterms. Critical loads are then calculated for Quercuspetraea, Pinus sylvestris and Picea sitchensis in order to determine the sensitivity of site critical load values to differences in base cation removal at harvest. The alternativeapproaches of using base cation to aluminium or calcium to aluminium for the biological limit term of the SMB equation arealso examined. Soil critical load values are shown to be influenced by the variability in both these terms, placing priority on the need for species and regional (or perhaps site)specific data similar to those presented here for the UK. 相似文献
5.
A sensitivity analysis was performed testingweathering rates, critical loads andexceedances for Swedish forest soils using Monte Carlosimulations of the PROFILE model. Different subsetsof input data were investigated with respect to theirpotential to reduce data uncertainty at site level butalso for modified estimates of the 5%-ile critical load andthe 95%-ile exceedance on 150×150 kmresolution. Physical soil properties were of dominantimportance for all sites and yield up to 62%reduction of the output standard deviation in weathering rate.The study showed that the critical ratio ofbase cations to inorganic aluminium (Bc/Al ratio) in the soilsolution was of major importance for reducingdata uncertainty in critical loads and exceedance estimates.The critical Bc/Al ratio was found to beimportant for reducing data uncertainties in modifiedestimates of the 5%-ile critical load and the95%-ile exceedance, in particular in the northern part ofSweden. Atmospheric deposition, uptake andlitterfall were more important for reducing data uncertaintyin the southern part. Physical soil propertiesand especially mineral content were found to be less importantfor reducing data uncertainties in criticalloads and exceedance estimates. The greatest scope forreducing data uncertainties in an applied perspectiveis to improve estimates of atmospheric deposition of anionsand cations as well as uptake and litterfall ofbase cations and nitrogen. 相似文献
6.
Critical acid loads for Dutch forests were derived using a multi-layer steady-state model that includes canopy interactions, nutrient cycling, mineral weathering and N transformations. Values were calculated for combinations of 12 tree species and 23 soil types for a 10×10 km grid. Critical acid loads thus derived increased with decreasing soil depth. Nearly 90% of the values varied approximately between 1500 and 4000 molc ha?1 yr?1 at 10 cm soil depth and between 750 and 2000 molc ha?1 yr?1 at the bottom of the rootzone. Separate critical loads calculated for N and S at the bottom of the rootzone varied between approximately 300 and 1000 molc ha?1 yr?1 for N and between 150 and 1250 molc ha?1 yr?1 for S. Using deposition data of 1990, a median reduction of the deposition by approximately 75% was calculated to achieve the critical loads at the bottom of the rootzone. The overall uncertainty in this value was estimated to be about 10%, although it can be much larger for specific soil types such as clay and peat soils. For N a larger reduction deposition percentage was calculated than for S, especially for coniferous forests with a high present N input. 相似文献
7.
Michael Starr Carl Johan Westman Johanna Ala-Reini 《Water, air, and soil pollution》1996,89(1-2):147-157
Batch acid addition experiments were carried out to determine the acid buffer capacities (amount of acid required to lower soil pH by one unit) of forest soils. Samples of O, E, B (or BC), and C horizons taken from 29 podzolic profiles in southern Finland were used in the experiments. Subsamples of soil were equilibrated for 24 h with NaCl solution containing additions of HCl acid. Cation exchange, mineral dissolution (weathering), and the protonation of organic matter all appeared to have been involved in the buffering of the acid additions. For the O horizon samples, most of the cations released in response to the acid additions were base cations. For the mineral soil samples, most of the cations released were Al3+ ions. With the exception of a few samples, the added acid was not fully neutralised and pH was lowered even with the lowest addition treatment. However, the acid addition treatments corresponded to many times the regional annual acid deposition load (1.6–2.0 cmol(c) m?2). Calculated acid buffer capacities (cmol(c) kg?1 pH?1) ranged from 9.8 to 40.8 for O horizon soil samples and from 0.1 (C horizon) to 5.2 (E horizon) for the mineral soil samples. Total acid buffer capacities for a profile (to a depth of 50 cm) ranged from 500 to 2349, with a mean value of 1091 cmol(c) m?2 pH?1. It is concluded that, in addition to CEC and base saturation, acid buffer capacity is a useful measure to describe the ecological effects of acid deposition on soil. 相似文献
8.
Shibata Hideaki Kirikae Machiko Tanaka Yumiko Sakuma Toshio Hatano Ryusuke 《Water, air, and soil pollution》1998,105(1-2):63-72
The proton budgets of deciduous and coniferous forest ecosystems on volcanogenous regosols in Hokkaido, northern Japan, were studied by measuring the biogeochemical fluxes (atmospheric deposition, canopy leaching, vegetation uptake and leaching from soil) at each site during a three year period. The proton budgets were developed for individual compartments of the ecosystem: vegetation canopy, organic and mineral soil layers. At both sites, atmospheric S deposition was the dominant proton source in the vegetation canopy. In organic horizons, dissociation of weak acids (bicarbonate and/or organic acids) and vegetation uptake of base cations were the dominant proton sources, and the net mineralization of base cations was the dominant proton sink. Atmospheric acid deposition was almost neutralized in the forest canopy and organic horizon. At both sites, weathering and/or ion exchange of base cations and protonation of weak acids (mainly bicarbonate) were the dominant proton sinks in the mineral soil. In both organic and mineral soil, internal proton sources (mainly vegetation uptake of base cations and dissociation of weak acids) exceeded external proton sources, indicating that acid deposition was not the main driving force of soil acidification in the studied forest ecosystems. 相似文献
9.
The molar ratio of base nutrient cations to total dissolved aluminum (BC : Altot) in the soil solution was measured at six forest sites in Switzerland in acid mineral soils to determine whether the ratio measured in the field was lower than the critical value of 1, as predicted by the mapping of exceedances of critical loads of acidity. The soil chemistry was then related to the soil solution composition to characterize the typical effective base saturation (BS) and BC : Al ratio in soil leading to critical BC : Altot in the soil solution. The median BC : Altot ratio in the soil solution never reached the critical value in the root zone at any sites for the whole observation period (1999–2002), suggesting that the BC : Altot ratios measured in the field might be higher than those modeled for the determination of critical loads of acidity. The gibbsite model usually applied for the calculation of critical loads was a poor predictor of the Al3+ activity at the study sites. A curvilinear pH‐pAl3+ relationship was found over the whole range of pH (3.8–6.5). Above a pH of 5.5, the slope of the pH‐pAl3+ relation was close to 3, suggesting equilibrium with Al(OH)3. It decreased to values smaller than 1.3 below a pH of 5.5, indicating complexation reactions with soil organic matter. The BS and the BC : Al ratios in the soils were significantly correlated to the BC : Altot ratios in the soil solution. The soil solutions with the lowest BC : Altot ratios (≤ 2) were typically found in mineral soils with a BS below 10 % and a BC : Al ratio in the soil lower than 0.2. In acid pseudogleyed horizons overlying a calcareous substrate, the soil solution chemistry was strongly influenced by the composition of the underlying soil layers. The soil solutions at 80 cm had pH values and BC : Altot ratios much higher than expected. This situation should be taken into account for the calculations of critical loads of acidity. 相似文献
10.
Tyler M. Sanderson Christopher Barton Claudia Cotton Tasios Karathanasis 《Water, air, and soil pollution》2017,228(10):403
Combustion of fossil fuels has contributed to many environmental problems including acid deposition. The Clean Air Act (CAA) was created to reduce ecological problems by cutting emissions of sulfur and nitrogen. Reduced emissions and rainfall concentrations of acidic ions have been observed since the enactment of the CAA, but soils continue to receive some acid inputs. Many soils sensitive to acid deposition are found to have low pH, a loss of base cations, and a shift in the mineral phase controlling the activity of Al3+ and/or SO4 2?. If inputs continue, soil may be depleted of base cations and saturated with Al and could cause low forest productivity. Soil samples and soil solutions from pan lysimeters were taken on ridge-tops in the Daniel Boone National Forest to evaluate potential impacts of acid deposition recently and in the future. Sample results were compared to historical data from identical locations. Physicochemical characteristics of the soils revealed that sites were very low in base saturation and pH and high in exchangeable acidity, illustrating change since previously sampled. Soil solution data indicated that sites periodically received high acid inputs leading to saturation of Al in soils and the formation of Al-hydroxy-sulfate minerals. Given these conditions, long-term changes in soil chemistry from acid deposition are acknowledged. 相似文献
11.
Shaodong Xie Jiming Hao Zhongping Zhou Ling Qi Hanhui Yin 《Water, air, and soil pollution》1995,85(4):2401-2406
The project Comprehensive Control and Demonstration for Acid Deposition in Liuzbou area is a national key project in the 8th Five-year-plan, and the study on critical loads will provide scientific and quantitative accordance for formulating control strategy. In this paper, critical loads of acid deposition to soil in Lirzhou area, China, were calculated using the Steady State Mass Balance method (SMB and PROFILE) and dynamic modeling methods(MAGIC), based on data obtained from field investigations and physiochemical properties measured through experiments such as the organic content, cation exchange capacity, base saturation, sulfate adsorption capacity, gibbsite coefficient, biomass base cation uptake and selectivity coefficient for cations. Weathering rates necessary to calculate soil chemistry in applying SMB and MAGIC model were determined by computation with PROFILE using independent geophysical properties such as soil texture and mineralogy as the input data, or by the total soil base cation content correlation. The results have shown that the critical loads of acidity in this area are in the range of 0.7–6.0 keq ha–1 yr–1, indicating sulfur deposition should be cut down by 50–90 percent of the present level. The upper soil layer is the most sensitive. The maximum allowable deposition loading of this area is also presented in the paper. 相似文献
12.
Analysis of the sensitivity of soils to acidification caused by the deposition of atmospheric pollutants has been one of the major scientific issues in Europe during the past few decades. In the present study, critical loads of acid deposition were calculated using the most accurate datasets available at present for European soils, by the “Simple Mass Balance” method. The results show that the soils most sensitive to acid deposition are Histosols, Cryosols and Podzols in cold areas in northern countries, followed by Lithic and Haplic Leptosols (Dystric) developed on acid parent materials. The highest critical loads corresponded to soils developed over calcareous rocks and soils in areas subject to high precipitation, even those dominated by poorly weatherable primary mineral. In the latter case critical alkalinity leaching is the main variable that determines the value of critical loads, because of the buffering action of the dissolution of aluminium compounds. The results were compared with those obtained by the Stockholm Environmental Institute in the same area, but with a different method of analysis. It was found that the results are highly dependent on the method used to perform the analysis. 相似文献
13.
J. Mulder N. Christophersen K. Kopperud P. H. Fjeldal 《Water, air, and soil pollution》1995,81(1-2):67-91
Here results are presented of a hydrochemical study at a pristine and two acid rain-impacted catchments in Norway. An analysis of streamwater chemical data interpreted as mixtures of observed soil solutions, is combined with data on the spatial distribution of soils. The analysis reveals that at all three sites low flow streamwater is dominated by groundwater, relatively rich in base cations, originating from the peat bogs adjacent to the brook. By contrast, high flow largely originates in catchment-specific acidic soil horizons on the hill slopes. Results indicate that short-term and long-term hydrochemical responses to acid deposition may differ between catchments which at first glance have a ‘similar’ make up of acidic soils. This illustrates the difficulty in selecting appropriate sites for comparative studies of the effect of acid atmospheric deposition on the chemistry of streamwater. 相似文献
14.
Critical loads of acid deposition for ecosystems in South China are derived by synthesizing the critical loads of acid deposition for soils, the critical loads of SO2 dry deposition for ecosystems, as well their exceedance. The results show in the southeast of Sichuan province around Chongqing municipality, the central and north of Guizhou province around Guiyang municipality, and the most areas of Jiangsu province, both the critical loads for soils and critical loads of SO2 dry deposition are exceeded. In Guangxi Zhuang Autonomous Region and some areas among Jiangxi, Zhejiang and Anhui provinces, the critical loads of SO2 dry deposition is the only restricting factor. There is no area where the critical load for soil is the only restricting factor in South China, so only the critical load for soil is not enough to be the basis to make sulfur abatement scheme. 相似文献
15.
White Catherine C. Smart Richard P. Cresser Malcolm S. 《Water, air, and soil pollution》1998,105(1-2):83-94
The majority of Scottish upland soils are particularly sensitive to acid deposition because of their low weathering rates. The compositions of the exchangeable base cations of such soils in the United Kingdom are dominated by sea salt inputs rather than by mineral weathering inputs of base cations. Catchments with low mineral weathering rates are also those particularly susceptible to freshwater acidification. Therefore, catchments exhibiting a high sea salt effect should also exhibit the most acid waters under base flow and storm flow conditions. A field evaluation study based on 61 catchments in NE Scotland has shown that this is indeed the case. River water pH under both base flow and high flow conditions is correlated stronhly with the relative contribution of Na+ to the sum of Ca2+, Mg2+ and Na+. From these results, an attempt is being made to produce a quantitative signature of weathering for the soils within the catchment upstream of the sampling point. Representative soil samples from the LFH, AE, B and C horizons and on 4 different parent materials have been obtained from the surrounding catchments to validate the above results for associated soil solutions. Sampling took place on upland moorland podzols under Calluna vulgaris. Tension lysimeters were used to sample the soil solutions so that their chemistry could be compared with that of the relevant river water. 相似文献
16.
Response of soil and soil water of podzols in the Kola Peninsula to acid deposition was estimated under both field and laboratory conditions. A significant increasing trend of exchangeable acidity in organic (O) horizons and exchangeable Al in podzolic (E) horizons of podzols with distance from the nickel smelter was observed. The simulated rain at pH 4.5 did not alter chemical properties of soils and soil solutions. As much as 95–99% of the applied H+ ions were retained by soils and appeared in the percolates after a treatment period that depended on acid load and soil thickness. Ca and Mg in soil solutions were highly sensitive to acid loading. Simulated acid rain enhanced the leaching of exchangeable base cations out of root zone. Acid inputs resulted in decreased pH, amount of exchangeable base cations and base saturation, in elevated exchangeable acidity and it's Al fraction in soil solid phase. The most significant changes occurred in O and E horizons. Substantial amounts of both Ca and Mg can be lost from the root zone of podzols in the north-western Kola, subjected to acid deposition, thus leading to forest productivity damage. 相似文献
17.
18.
The long‐term sustainability of forest soils may be affected by the retention of exchangeable nutrient cations such as Ca2+ and the availability of potentially toxic cations such as Al3+. Many of our current concepts of cation exchange and base cation saturation are largely unchanged since the beginnings of soil chemistry over a century ago. Many of the same methods are still in use even though they were developed in a period when exchangeable aluminium (Al) and variable charge were not generally recognized. These concepts and methods are not easily applicable to acid, highly organic forest soils. The source of charge in these soils is primarily derived from organic matter (OM) but the retention of cations, especially Al species, cannot be described by simple exchange phenomena. In this review, we trace the development of modern cation exchange definitions and procedures, and focus on how these are challenged by recent research on the behaviour of acid forest soils. Although the effective cation exchange capacity (CECe) in an individual forest soil sample can be easily shown to vary with the addition of strong base or acid, it is difficult to find a pH effect in a population of different acid forest soil samples. In the very acidic pH range below ca 4.5, soils will generally have smaller concentrations of adsorbed Al3+. This can be ascribed to a reduced availability of weatherable Al‐containing minerals and a large amount of weak, organic acidity. Base cation saturation calculations in this pH range do not provide a useful metric and, in fact, pH is modelled better if Al3+ is considered to be a base cation. Measurement of exchangeable Al3+ with a neutral salt represents an ill‐defined but repeatable portion of organically complexed Al, affected by the pH of the extractant. Cation exchange in these soils can be modelled if assumptions are made as to the proportion of individual cations that are non‐specifically bound by soil OM. Future research should recognize these challenges and focus on redefining our concepts of cation retention in these important soils. 相似文献
19.
N. B. Kuznetsov S. A. Alekseeva G. V. Shashkova T. Ya. Dronova T. A. Sokolova 《Eurasian Soil Science》2007,40(4):353-366
Soil samples from the main genetic horizons of pale podzolic and peat gleyic podzolic soils from the Central Forest Reserve were subjected to a continuous potentiometric titration by sulfuric and nitric acids. The sulfate sorption capacity was determined in soil mineral horizons. The buffer capacity of mineral horizons of both soils to sulfuric acid was found to be higher than that to the nitric acid. This is explained by the sorption of sulfates via the mechanism of ligand exchange with the release of hydroxyl groups from the surfaces of Fe and Al hydroxide particles and edge faces of clay crystallites. The buffer capacity of organic horizons of the pale podzolic soil to sulfuric acid proved to be higher than that to nitric acid; in organic horizons of the peat gleyic podzolic soil, the buffer capacity to sulfuric acid was lower than that to nitric acid. The reasons for this phenomenon have yet to be investigated. 相似文献
20.
L. I. Inisheva 《Eurasian Soil Science》2006,39(7):699-704
This paper considers three topical problems—the definition of peat soils as natural-historical formations and the estimation of their profile thickness, the analysis of the genesis of organic soils, and the principles of the classification of peat soils. Based on the experimental data of long-term studies, it was concluded that peat soils may include the whole peat layer and the upper horizons of the surface mineral soil. The organic and mineral parts of the natural structures were found to be a genetically homogeneous soil profile, which has the same history of development. The upper layer of the peat soils should be considered as the horizon reflecting the contemporary stage of the soil formation. A hierarchy of peat soils is analyzed for developing their classification. 相似文献