Organochlorine pesticide and PCB contents in otter (Lutra lutra) scats from western Scotland

Organochlorine pesticide residues and PCBs were measured in 113 otter (Lutra lutra) scat samples from 94 sites in the River Clyde catchment, its estuary and neighboring coastal waters in western Scotland. Contents of pesticide residues were generally low. PCB amounts were high in some regions in the study area (geometric mean contents up to 19.5 mg kg^?1 lipid). Potential sources of contamination included industrial areas, a sewage sludge dump and shipping facilities, both naval and commercial. PCBs in tissues were estimated from scats. Analysis of scats provides a useful technique of estimating potential contamination threats to otter populations and can be used to identify biologically significant hot-spots of contamination which may be missed by more familiar surveillance methods.     

The otter Lutra lutra in Albania

During a survey in Albania we found signs of otters at 17 (54·8%) of the 31 stations investigated. Otters were widespread in much of the country, and healthy populations were localised in rivers and marshes in the north-west and in the south. Average sprainting activity was 1·7 positive sites per 200 m and 3–6 spraints per 200 m. Frogs, probably Rana ridibunda, as well as fish, appeared to be important prey for otters. In the coastal plains, several rivers were grossly polluted and the growing agricultural and industrial development may endanger the survival of otters.     

Organochlorine Compounds (pesticides and PCBs) in Scats of the European Otter (Lutra lutra) from an Actual Expanding Population in Central France

Scats of the European otter (Lutra lutra) were sampled along the Allier river (France) catchment for organochlorine toxic compounds (nine pesticides and 16 PCBs congeners) measurement. From early 2004 to June 2005, 90 sites of 40 rivers were twice investigated, and 71 scats samples collected, in four geographical areas being naturally re-colonized by the species since its legal protection. Detectable pesticides and PCBs were found in 100% of the samples. Mean values reached 2.72 and 13.58 mg kg^?1 (lipid weight) for pesticides and PCBs, respectively. Amounts were significantly different between the four areas investigated. A significant increase in medium and absolute values is noted by going downstream of the catchment. Potential medium- and long-term consequences on the observed population increase are discussed.     

Estimation of Polychlorinated Biphenyl (PCB) Levels in Livers of the Otter (Lutra Lutra) from Concentrations in Scats and Fish

The decline of the European otter (Lutra lutra) seems to be related to environmental contamination especially with polychlorinated biphenyls (PCBs). Only a limited number of tissue samples from otters killed accidently as traffic victims or drowned in fishnets are available for residue analysis. Calculating the levels of PCBs in otter tissues from concentrations in fish and scats would be a very valuable tool to estimate potential risks for this endangered species. PCB levels measured in otter livers, scats and fish from a Middle European otter population were used to examine the suitability of mathematical models for calculating PCB concentrations in otter liver from fish concentrations and from scat levels. Our results suggest that the models and input parameters currently used to calculate PCB concentrations in otters to estimate risks do not predict mean concentrations in otter livers in our Middle European study area, giving lower concentrations than actually analysed in the tissues. Possible causes for the observed discrepancy between measured and calculated values are discussed.     

Acidification phenomena in beech (Fagus sylvatica) forests of Europe

When comparing the species composition of herb layers in loess beech forests of the Westphalian Bight (Northrhine-Westphalia, F.R. Germany) in the years 1976 and 1983, findings show that acidophilic plants tended to be favored during this period. Apart from many other factors, depositions have also been considered as causes for this. Where they should actually play a role, comparable locations having a higher acid deposition rate would have to show a stronger tendency towards acid-indicators than those having a lower one. It is the stemflow area of the beech tree (Fagus sylvatica L.) which attracts more precipitation than the rest of the forest area, on account of its infundibular treetop. Furthermore, stemflow water from Fagus sylvatica exhibits a higher degree of acidity than rain dripping from the treetop. Thus, the stemflow area as an area with higher acidic incidence may be compared with the normal forest area displaying minor acidic incidence. Findings from all the surveys so far conducted in Middle Europe show that soil pH recorded in the stemflow area is distinctly lower, and that there are less base- and weak acid-indicators but correspondingly more (strong) acid-indicators, than in “normal” forest soil. It must be noted that the phenomena observed need not be due to acidic precipitation. They could as well be attributable to a special feature pertaining to the stemflow area of the beech as specifically natural phenomena. In the event of natural causes being detected, these would have to be observable in the overall growth area of the beech. In Southern Europe, however, we did not find any indication whatsoever for acidification of the stemflow area. This phenomenon appears to be restricted to Central European regions affected by higher pollution.     

Trends in Surface Water Acidification in Europe and North America (1989–1998)

During the last 20 years, emission reductions in Europe and North America have resulted in decreased atmospheric S-deposition of up to 50%, while N-deposition has stayed almost constant. Data from 98 ICP Waters sites were tested for trends in concentrations of major chemical components for the 10-year period 1989-1998 using the nonparametric seasonal Kendall test. The sites were grouped into regions and types for meta-analysis. All of the regions had highly significant downward trends in SO₄ ^2?* concentrations. Nitrate concentrations, on the other hand, show no regional patterns of change. Concentrations of base cations declined in most regions. All regions showed tendencies of increasing DOC. The low ANC sites showed the largest rates of recovery. Neither the high NO₃ ^? or low NO₃ ^? groups of sites exhibited significant trends in NO₃ ^? concentrations. Alpine (non-forested) sites show clear and consistent signals of recovery in ANC and pH, and appropriate (relative to SO₄ ^2?* trends) rates of base cation decline.     

Status, distribution and definition of mycologically important grasslands in Scotland

In northern Europe, unimproved grasslands provide the habitat for a diverse group of fungi, including members of the genera Camarophyllopsis, Hygrocybe, Entoloma and Dermoloma, and the families Clavariaceae and Geoglossaceae. These fungi are currently the focus of international conservation concern, owing to rapid declines in the availability of suitable habitat. To assess their status in Scotland, 621 field surveys were undertaken on a total of 511 sites, distributed throughout the country. Taxa were found to differ substantially in abundance; for example, whereas five Hygrocybe taxa were recorded at a single site, seven taxa were recorded on more than 200 sites. The number of Hygrocybe taxa per site was found to be positively correlated with number of Clavariaceae taxa (r=0.60); however, the total number of Entoloma taxa was poorly correlated with diversity of other groups (r<0.35). Detrended correspondence analysis (DCA) of field data highlighted variation in composition of fungal communities; in particular, Entoloma taxa were found to cluster together, and were rarely found in association with Geoglossaceae. The data were used to critically examine current approaches to defining the conservation importance of grassland sites on the basis of their mycota. Species accumulation curves indicated that more than 16 visits may be required to fully characterize the fungal diversity of a site. Different groups of fungi also displayed constrasting patterns of seasonal variation in sporome production; peak diversity values for Geoglossaceae and Clavariaceae tended to occur later in the year than for Hygrocybe and Entoloma. Such results indicate that intensive, multiple surveys over prolonged periods are required to accurately define the conservation value of grassland sites. However, these preliminary data suggest that the unimproved grasslands of Scotland are of exceptional importance for fungal conservation, compared with other countries of northern Europe.     

Rare earth and other trace and major elemental distribution in a pedogenic calcrete profile (Slimene,NE Tunisia)

A calcrete profile developed on the top of a calcareous consolidated dune located in a coastal area of NE Tunisia (semi-arid climate) was studied with the aim to investigate the behavior of the chemical elements (rare earth elements—REE—and other trace and major elements) during the processes associated with calcrete formation, particularly dissolution and precipitation of carbonates in the vadose zone. The profile shows a vertical sequence, with clear zonations from the surface downwards: a reddish soil at the land surface, a nodular horizon, a laminar-structured level, and the consolidated old dune. Chemical and mineralogical analyses of samples from all levels were performed by neutron activation analysis and X-ray diffraction (bulk samples and < 2 μm fraction). Detailed studies of iron speciation and iron minerals were done by Mössbauer spectroscopy. Microfauna, mineralogical and chemical variations in the Slimene weathering profile point to a long term aerial exposure of the old dune in a semi-arid carbonated environment leading to the development of a pedogenic calcrete profile. The mineralogical variations with depth indicate carbonate dissolution at the surface and downward leaching of calcium. Secondary carbonates overgrow primary ones and precipitate as coating or concretions below. Minerals found in the upper levels correspond to original materials of the old dune and also weathering phases and atmospheric inputs. Phyllosilicates decrease while calcite and K-feldspars increase with depth. Kaolinite was the only clay mineral found in the old dune. Illite and chlorite were also found in all samples with calcrete. Authigenic smectite formation occurs above the laminar-structured calcrete due to restricted drainage conditions. The most significant chemical variations associated with the calcrete formation are (i) enrichment of Co, U, Br, and REE in calcrete; (ii) depletion of middle REE in the upper levels, particularly Eu, and enrichment of middle REE and heavy REE in calcrete; and (iii) Hf, Zr, Cr, Th, Cs, Ta, Ga, Rb, and K appear to be retained in the upper levels, where calcite has been dissolved. Here iron is more reduced. Fe³⁺ occurs in iron oxides (goethite and hematite), and clay minerals. The ratio goethite/hematite appears to increase down the profile; and Fe²⁺ is mainly present in clay minerals.     

Acidification of Growing Cloud Droplet by Rainout of SO2(g)

Growing cloud droplets absorb such atmospheric gaseous pollutant as SO₂(g), condensing atmospheric water vapor into themselves. Then, the cloud droplets are acidified by absorption of SO₂(g) during condensational growth on cloud condensation nuclei (CCN). Characteristics of this process, which is a part of rainout, have not been made clear yet. In order to estimate the contribution of rainout to acid rain formation, the acidification of growing cloud droplets is investigated numerically, using a mathematical model. The numerical simulations show that: (1) the time to attain the equilibrium state for mass transfer (acidity and growth) and heat transfer (temperature) is much longer than the time for disappearance of CCN; (2) time variation of acidity and temperature of cloud droplets are greatly dependent on the existence of undissolved CCN; and (3) there seems to be a close correlation between the time variation of the acidity and that of the temperature.     

Soil Acidification and Decline of Trees in Forests Within the Precincts of Shrines in Kyoto (Japan)

The historical Japanese city of Kyoto boasts a great many old Buddhist temples and Shinto shrines, many of which are surrounded by sizable forests that have long been preserved as sacred forests. However, acidic deposition has been fallen on the forests in Kyoto for many years. For this study, we conducted soil surveys and investigated the extent of decline of the trees in two Shinto shrines as historic monuments of ancient Kyoto. Our study revealed clear decline in two key tree species (Cryptomeria japonica (Japanese cedar) and Chamaecyparis obtusa (Japanese cypress)) in both shrines, with some trees showing signs of mortality. The soil was acidic, with an average pH of 4.35. Nutrient salt content too was only about one tenth the national average, with exchangeable Ca (0.52 cequiv./kg) and Mg (0.23 cequiv./kg) for 0?C20 cm surface soil. The (Ca+Mg+K)/Al molar ratios were also very low, with 80% of all soil samples having a ratio of 10 or below. Such soil conditions are thought to hamper the sound growth of both Japanese cedar and Japanese cypress, and soil acidification is one of the most likely causes of the decline of temple and shrine forests in Kyoto.     

Acidification Trends in Surface Waters in the International Program on Acidification of Rivers and Lakes

We applied trend analyses to data from the International Cooperative Programme forAcidification of Rivers and Lakes in an attempt to discover regional patterns of long-term changesin surface water chemistry both in Europe and North America, and to relate these changes totrends in deposition. Decreases in surface water SO ₃ ^- concentrations predominated at European sites in theFederal Republic of Germany, The Netherlands, and in Norway, and at the North American sitesin Ontario, Canada, the Adirondacks and Catskill Mountains of New York, U.S.A. Otherpredominating trends in the European sites were decreasing Ca²⁺ concentrations at many of thesites in The Netherlands, Norway, and Sweden. Increases in NO ₃ ^- were observed at several sites in southern Norway, and in theAdirondack and Catskill regions of eastern New York. This, combined with an increasedoccurrence of declining base cation concentrations may well be responsible for the lack ofdocumented surface water recovery from acidification. Despite region-wide trends in severalvariables of importance in acidification, no correlations between surface water trends and changesin deposition were found using these data.     

土壤酸化作用对磺胺氯哒嗪吸附行为的影响

参照OECD guideline 106批平衡方法研究酸化作用对磺胺氯哒嗪在黑土中的吸附动力学、吸附热力学以及有机质和离子强度对其吸附的影响。结果显示:酸化作用下磺胺氯哒嗪在黑土中吸附平衡时间为12 h,准二级动力学方程拟合的酸化黑土中的吸附速率常数(k_2)为216.275 5 mg/(g·h),大于对照黑土中的15.722 2 mg/(g·h);从吸附热力学结果看,酸化作用明显提高磺胺氯哒嗪与黑土的结合能力,其吸附量与温度呈负相关;从吸附自由能(ΔG)结果看,其吸附过程是以物理吸附为主的自发反应,但酸化作用使|ΔG|增大,体系更稳定且更易进行自发反应;添加有机质可以增加黑土对磺胺氯哒嗪的吸附,但在酸化黑土中增加效果不如对照黑土;磺胺氯哒嗪在黑土中的吸附能力随背景溶液Ca~(2+)浓度增大而减小,酸化作用下使其与Ca~(2+)产生竞争关系,离子浓度越大竞争能力越强,黑土对磺胺氯哒嗪的吸附量则越少。     

Characteristics of Raindrop Acidification by Co-Washout of SO2(G)-H2O2(G)-HNO3(G)

In order to investigate the acid rain formation under the coexistence of SO₂(g), H₂O₂(g), and HNO₃(g) in the air, a mathematical model has been built and some numerical simulations have been carried out with use of the model. The simulation reveals that SO₂(g) absorbed into a raindrop is released and then re-absorbed as the fall distance increases. The desorption and re-absorption processes of SO₂(g) are caused by: (1) the fact that the equilibrium concentration of H₂O₂(aq) and HNO₃(aq) in raindrops are much higher than that of SO₂(aq), and (2) the fact that the oxidation reaction rate of HSO₃ ^? with H₂O₂(aq) increases with H⁺ concentration in raindrops. The degree of acidification of the rainwater has been estimated by introducing a raindrop size distribution. The acidification is mainly caused by the adsorption of SO₂(g) in the usual case where the atmospheric concentration of SO₂(g) is much higher than that of HNO₃(g). With the increase in the atmospheric concentration of HNO₃(g), the concentration of H⁺ generated from SO₂(g) decreases and the contribution of HNO₃(g) to the generation of H⁺ becomes dominant.

     

Geologic Sources of Sulphur at Dargall Lane (Galloway,Scotland)

Dargall Lane is an acidic stream draining a moorland catchment in the Galloway Hills of southwest Scotland. This area has been receiving high atmospheric loadings of sulphur. The Dargall Lane catchment is underlain by a greywacke-shale sequence and by intrusive rocks of granodioritic-tonalitic composition. The shales have a sulphur concentration in the range 0.04–0.19 wt.%, whereas mudstones, greywackes and grandiorites rarely exceed 0.02 wt.% S. Calculations based on bedrock chemical composition, typical denudation rates of sedimentary and intrusive rocks, and the composition of surface water during baseflow, indicate that geogenic sulphur may account for a significant fraction of the sulphate hydrochemical budget. Sulphur mobilised by rock weathering of black shales is likely to be an important contributing factor causing the observed lack of a significant sulphate decrease in sulfate water despite the reported 30% reduction of sulphate in atmospheric precipitation during the past decade.     

Long-Term Soil Acidification Model (LTSAM) Development and Application for Analyzing Soil Responses to Acidic Deposition

A long-term soil acidification model (LTSAM) which can describe calcareous and non-calcareous soil responses to acidic deposition is developed based on the conservation of alkalinity and Ulrich buffer ranges. The model which considers nine major ions of armospheric deposition, has focused on certain soil processes (weathering of carbonates, silicates, and aluminum (Al) oxides or hydroxides, cation exchange, anion retention, and CO2 solubility). After comparing the model design and simulation results with the SMART, the paper describes several numerical experiments on the sensitivity of calcareous drab soil in Beijing and red earth (nearly dystric cambisol) in Wenzhou of Zhejiang Province in Southern China to acidic deposition scenarios. The modelling results indicate that increase or decrease in atmospheric deposition of base cations and not only changes in deposition of sulfate (S) and H+ must be considered in assessment of critical loads both for red earth and calcareous drab soil.     

Acidification in Norway — Status and trends

Surface and ground water monitoring in Norway is designed to give a regional coverage with most of the stations in areas with acidification and some stations in unpolluted areas that give background values. Surface water (weekly sampling) and precipitation (daily measurement) are monitored at 6 calibrated catchments, 5 located in southern Norway and 1 in northernmost Norway close to the Russian border. Ground water (weekly sampling) is monitored in 4 reservoirs in Southern Norway. 73 lakes located all over Norway are surveyed each fall. Nineteen rivers in western and southern Norway are monitored by monthly sampling. All sites are considered sensitive to acidification and are chosen to minimise the effects of anthropogenic catchment based impacts. Results from the monitoring over the period 1980–1994 show that there is a reduction of sulphate of about 25–35% in surface waters which is related to a 30–45% reduction in sulphate concentration in precipitation. An improvement in water quality as measured as increase in ANC has only been apparent since 1990. Due to heavy seasalt episodes in the most coastal catchments like Birkenes and the rivers in western Norway, there has been no improvement of ANC since 1980. Deposition of nitrogen has not changed over the last 10 years, and there is no change in the levels of nitrate in the monitored surface waters.     

Acidification of Solid and Solution Phases at Greater Depths (> 150 cm) at Solling Spruce Site

The acidification of the soil and percolation water at soildepths from 150 to 500 cm was studied at the Solling spruce sitefrom 1991 to 1996. NH₄Cl exchangeable cations of the fineearth and bedrock fractions were obtained from different depthsand the soil solution composition was monitored at 150, 200,300, 400 and 500 cm depths using seven suction lysimeters at each depth.In the seepage water collected from 150 and 200 cm depth, pHvalues decreased in the period 1991 to 1996, but no significantchanges were observed in solutions collected below 200 cm depth.Element budgets of Al and M_b (Na, K, Mg, Ca) cationsindicated that buffering by exchange of Al with M_b cationsoccurred mainly in surface 200 cm soil depth. High variabilities in concentrations of SO₄ (at 150 cm) andM_a (Al, Mn, H, Fe) cations (at 300 and 500 cm) wereobserved. High variabilities in M_a cations could beassigned to one of the lysimeters at each depththat extracted low pH solutions. The amount of exchangeablecations in the fine earth and the bedrock fractions indicatedthat the acidification front (exchangeable M_b cations < 80equivalent percent) had occurred to soil depth of more than 360cm, but the extent of acidification that might have occurred inthe preindustrial period is not known. In both fine earth andbedrock fractions, depthwise changes of exchangeable M_a andM_b cations were quite similar, suggesting that rockfractions have contributed to proton buffering not only bysilicate weathering but also by cation exchange.     

Zinc distribution in Zimbabwean soils and its relationship with other soil factors

Abstract

The distribution of zinc in some major Zimbabwean soils was studied using 120 profiles taken from 22 different locations. The total zinc status (TL‐Zn) of the horizons of soils studied was low (8 ppm), and the range was narrow (3.7 to 16.3 ppm). The residual zinc (RS‐Zn) fraction was about 65 percent of the total zinc found in the soils, while 15 percent was organically bound zinc (OG‐Zn), 14 percent was available zinc (MG‐Zn), and 6 percent was zinc associated with hydrous metal oxides (OX‐Zn). The total zinc status of the soils was related to parent material. Generally, texture had a significant effect on zinc distribution with heavier textured soils having more zinc in most fractions than the lighter textured soils. A decrease in zinc down the profile was observed for available, residual, and total zinc. If cropped intensively, 32 per cent of the soils with less than 1 ppm available zinc have the potential for zinc deficiency. Multiple stepwise regression analysis showed that organic matter, silt and clay contents, available copper, and resin P₂O₅ contents were important for predicting the available zinc content of the soils, while texture and organic matter content were important in predicting total zinc content.     

Determination of antagonism between cyhalofop-butyl and other rice (Oryza sativa) herbicides in barnyardgrass (Echinochloa crus-galli)

Herbicide antagonism is defined as the reduction of control of certain weeds as the result of applying mixtures of two or more herbicides. Cyhalofop-butyl, a graminicide used for postemergence grass weed control in rice, is antagonized by some rice herbicides when applied simultaneously. The result of this type of antagonism usually results in decreased control of grass weeds. Research has shown that herbicide antagonism between graminicides and other herbicides may be caused by different mechanisms as the result of activity of the tank-mix partner. Using HPLC, the objective of this experiment was to analyze the fate of cyhalofop-butyl in barnyardgrass tissue when applied alone and in combination with halosulfuron, propanil, or triclopyr. Results indicated that absorption of cyhalofop-butyl and hydrolysis to its phytotoxic metabolite, cyhalofop-acid, was rapid and that halosulfuron and triclopyr had no effect. Because of a likely interaction of propanil with an apoplastic esterase enzyme, increased levels of cyhalofop-butyl and cyhalofop-acid were detected in barnyardgrass tissue, indicating that cyhalofop-butyl metabolism was hindered by propanil.     

Resistance of Organic Horizon to Acidification from Snowmelt in Podzolic Soil of the Kola Peninsula (6 pp)

Background  

The Kola Peninsula (the most northern region of the European fringe of Russia) is covered with podzolic soil and is considered the most sensitive area to acidification in Europe because of the low input rate of base cations by weathering. About 300 thousand tons of SO2 are annually emitted from stationary sources in this region. Acidic precipitation accumulates in the snow during winter, and acidic water suddenly flushes into the soil during spring snowmelt (so-called acid shock). It is therefore important to assess how the acid-sensitive podzol responds to an intensive increase in acid load. The main purpose of this paper is to show the observed data rather than to provide an analytical interpretation of the observed phenomenon.