The impact of nitrogen deposition on upland surface waters in Great Britain: A regional assessment of nitrate leaching

A national dataset of water chemistry collected for critical loads mapping is used to make a regional assessment of surface water nitrate concentrations in Great Britain. The primary data are dominated by high concentrations in lowland regions Where N inputs are dominated by non-atmospheric sources. Land cover data are used to screen out sites with potential catchment sources of N, allowing the evaluation of nitrate leaching due to atmospheric deposition alone. In the screened dataset several upland regions show elevated nitrate concentrations, notably Wales, the Pennines, Cumbria, Galloway and the Cairngorms, and there is a clear relationship between surface water nitrate and total N deposition.     

Monitoring the impact of acid deposition on the soil microbiota,using glucose and vanillin decomposition

Samples of organic (F/H) and mineral soil (to approximately 8 cm depth) were collected from three ‘ecologically analogous’ sites in a boreal forest at intervals of 2.8 km (site 1), 6.0 km (site 2) and 9.6 km (site 3) from a ‘sour gas’ plant emitting S0₂. The organic soil of site 1 was characterized by a lower basal respiration rate, smaller microbial biomass, and a longer time to attain the peak rate of CO₂ efflux following enrichment with glucose or vanillin (0.15 and 0.1 g (15 g soil)^?1, respectively). No significant differences were detected between the mineral soils of the 3 sites in terms of the rate or extent of glucose decomposition (0.1 g (100 g soil)^?1), but there was a significant retardation in vanillin decomposition in the mineral soil of site 1 (0.05 g (100 g soil)^?1). Concentrations of 0.075 and 0.1 g vanillin (100 g soil)^?1 were decomposed in the mineral soil of sites 2 and 3, but not at site 1. Following incubation with vanillin, fewer bacteria were isolated from both the organic and mineral soils of site 1, and a greater proportion of these were spore formers and bisulfite-tolerant isolates compared with those from sites 2 and 3.     

Critical loads of SO4 for surface waters in the Kola region of Russia

Precipitation falling on the Kola North of Russia is severely polluted by strong acids and heavy metals emitted from large local smelters operated by the Severonickel and Pechenganickel companies. Large areas in the affected region are considered sensitive to acid precipitation due to geological and climatological conditions. Extensive surface water acidification has taken place, particularly, in the mountain and remote tundra regions. Critical loads and their cxceedances have been calculated for 370 lakes sampled in the Kola peninsula. These data indicate that the surface waters in the Kola North are highly sensitive to acidic deposition. Using the minimum values determined for each NILU grid cell, critical loads of less than 20 meq/m²yr occur in about 50 percent of the area.     

The impact of changes in sewage treatment on seaducks wintering in the Firth of Forth,Scotland

Changes in the numbers and distribution of seaducks wintering in the Firth of Forth off Edinburgh following the introduction of sewage treatment are described. Numbers of scaup and goldeneye were considerably reduced and feeding flocks were only recorded at outfalls where sewage continued to be discharged in large quantities.Although food items borne in the sewage were important in determining local distribution patterns, it was unclear whether these or abundant invertebrates were the most important factor attracting seaducks to this area.As a result of an environmentally desirable improvement scheme the United Kingdom has lost an internationally important concentration of wildfowl.     

Effect of acid deposition on forested catchment in the western Tokyo,Japan

Acid deposition and its effect on Andisols were investigated in the forest experimental station, the Rolling Land Laboratory (RLL), located in the Tama Hill region of Central Japan. The annual volume-weighted mean pH value of open bulk precipitation was 4.8 in the period 1990 to 1992. Nitrate deposition at RLL was larger than for sulfate, which was obviously different from results in Japan Environment Agency (JEA) stations or in study areas of Europe and North America. Abundant nitrate deposition was ascribed to the high emissions from a non-point source, mainly cars. Although sulfate concentration in throughfall fluctuated, its concentration in soil solution was kept at a low level. This was attributed to the high sulfate adsorption capacity of the Andisols.     

The influence of organic acidity on the acid-base chemistry of surface waters in Maine,USA

Results from surveys of low-ANC lakes (high elevation, and seepage lakes), and of surface waters in dystrophic, acidic bogs, indicate that acidic precipitation and organic acidity are each generally necessary, but not solely sufficient, for chronically acidic status in Maine lakes. Acidic, low DOC (ANC < 0; DOC < 5 mg L^-1) lakes of all hydrologic types are acidic due largely to acidic deposition; high DOC (DOC > 30 mg L^-1) acidic seepage lakes are acidic due largely to organic acidity, and high DOC drainage lakes are acidic due to a combination of both factors. No low DOC drainage lakes are known with pH less than about 5.0, suggesting that organic acidity is necessary to depress lake pH values to below 5 in Maine at current deposition loadings,The dominant anion of low DOC, acidic waters is sulfate. Acidic waters with intermediate concentrations of DOC (5 to 30 mg L^-1), may be dominated by S04 and/or organic acidity. Seepage-input lakes were the only group to include both organically-dominated (37% of the acidic lakes) and S0₄-dominated members (63% of the acidic lakes). High DOC systems are typically low pH bogs, and are all organic acid-dominated.     

Geochemical characterisation of surface waters,topsoils and efflorescences in a historic metal-mining area in Spain

Purpose

Mining activities generate large amounts of wastes that may contain potentially toxic elements (PTE), which, if released into the environment, may cause air, water and soil pollution long after mining operations have ceased. This paper describes the environmental relevance of efflorescences, topsoils and surface waters from the abandoned mine of Sierra Minera of Cartagena-La Unión, SE Spain. The exposure of the population to arsenic and the associated risk were also assessed.

Materials and methods

A total of 10 topsoils and surface waters and 11 efflorescences affected at varying degrees by mining activities were studied. The total potentially toxic element content (As, Cd, Cu, Fe, Pb and Zn) was determined in all samples. In addition, the mineralogical composition of solid samples was determined by X-ray diffraction and some efflorescences were also analysed using a scanning electron microscopy-energy dispersive X-ray spectrometer. Finally, an arsenic-intake risk assessment was carried out, both as regards carcinogenic and non-carcinogenic effects and considering the total and the bioaccesible As content.

Results and discussion

The study area is heavily polluted as a result of historical mining and processing activities, during which time great amounts of wastes were produced, characterised by a high PTE content, acidic pH and minerals resulting from supergene alteration. The supergene mineralogical assemblages include soluble metal salts, mainly sulphates, iron hydroxysulphates and iron oxyhydroxides, all of which form ochreous precipitates. Topsoil samples showed risk values and hazard quotients higher than the reference levels, particularly for children. In the efflorescences, these values were lower but still unacceptable.

Conclusions

The efflorescences are of significance for monitoring purposes because they are involved in cycles of retention release of hydrogen ions, sulphate and potentially toxic elements. In addition, in a semi-arid climate, such as the study area, these minerals contribute to our understanding of the response of the system to episodic rainfall events. In general, it was observed that the arsenic in collected samples represent a potential risk for human health through ingestion.

     

The impact of high speed, high volume traffic axes on brown bears in Slovenia

The Ljubljana-Razdrto highway and the parallel Ljubljana-Trieste railway cut through critical brown bear (Ursus arctos) habitat in south-central Slovenia. These high speed, high volume traffic axes are located close to the main dispersal corridor for bears from the Dinaric Mountain range into the Alps. We analyzed radiotracking data of 15 individual bears that lived within 10 km of the highway, compared transportation related and overall known bear mortality, and analyzed the spatial distribution of bear-vehicle accidents. The highway posed a home range boundary to resident bears, but was not an absolute barrier. Transportation-related mortality was high in the vicinity of the highway and railway, and averaged 31% of the total known local mortality from 1992 to 1999. At present the detrimental impact of transportation routes on the bear population in Slovenia is modest due to the high density of bears and the low density of highways—but new highways are planned or already under construction. Managers have to be aware that, due to bears large home ranges and long dispersal distances, a single highway affects bears from a huge area—emphasizing the importance of international cooperation and a landscape approach in highway planning.     

Influence of acid deposition on element cycling in mature sugar maple forest,Algoma, Canada

Forestry studies were undertaken within the Turkey Lakes Watershed to determine the impact of long-range transport of air pollutants on biogeochemical processes in old-growth sugar maple forest on shallow Precambrian-derived till soils in the Algoma District of Ontario, Canada. Distributions of organic matter and macroelements were determined in the tree- and field-layer vegetation, the forest floor and the mineral soil of the study site. Annual tree growth was largely offset by mortality, resulting in a relatively stable standing stock of ca. 245 t ha^?1. Annual aboveground litter production averaged 3.7 t ha^?1 yr^?1, chiefly in the form of deciduous leaf fall. The average pH of the precipitation (4.3) was reduced considerably by contact with the forest canopy. Throughfall was enriched with other elements, principally K and, to a lesser extent, Ca and Mg. The cationic composition of the forest-floor percolates, on the other hand, was dominated primarily by Ca and only to a lesser extent by Mg and K. The stand receives moderate acid deposition, mainly from average inputs of 33–36 kg ha^?1 yr^?1 of SO₄ ^2? and 24–29 kg ha^?1 yr^?1 of NO₃ ^? distributed throughout the year. Atmospheric inputs add to substantial natural NO₃ ^? production, notably within the forest floor and upper mineral soil, and contribute to leaching of bases, principally Ca and Mg, from the rooting zone. Active recycling of elements together with weathering of primary minerals should assist in preserving the base status of the site.     

Summertime study of acid deposition in the Detroit area

A comprehensive acid-deposition measuring station has been set up at the General Motors Technical Center site in Warren, Michigan. A second station is also being operated at a rural site near Lapeer, Michigan, which is approximately 54 km north of the Warren site. This report presents the results of this study for the June-September 1981 period. The rain composition was similar at both sites with the pH averaging 4.1 and the SO₄ ⁼/NO₃ ^? equivalence ratio averaging 2.1:1. This similarity suggests that local sources, i.e., relatively high emissions near the Warren site, and low emissions near the Lapeer site, have little effect on rain composition. The SO₄ ⁼/NO₃ ^? ratio for individual rain events in Warren reflected the SO₂/NO_x emission ratio in the area from which the event had come. Thus, the highest SO₄ ⁼/NO₃ ^? ratios were observed for rains that arrived from the southeast and the lowest ratios for rains from the southwest. No rain events arrived from a northwesterly direction during this sampling period. Measurements were carried out at both sites to estimate the relative contribution of dry deposition. The ambient particulate was acidic about half the time and basic half the time. The acidity in the particulate was due to acid SO₄ ⁼ and the basicity was due to soil-related materials. Gaseous HNO₃ averaged 2.0 μg m^?3while the basic gas, NH₃, averaged 0.83 μg m^?3. Based on these measurements, it was estimated that dry deposition of particles and HNO₃ contributed less than 10% of the total deposition of acidity during this study period.     

A conservation framework for the golden eagle in Scotland: Refining condition targets and assessment of constraint influences

Conservation strategies have three elements: species protection, site protection and, the most challenging component, conservation in the wider environment. Watson and Whitfield [Watson, J., Whitfield, P., 2002. A conservation framework for the golden eagle Aquila chrysaetos in Scotland. Journal of Raptor Research 36(1 Suppl.), 41-49.] proposed a conservation framework for the golden eagle in Scotland whose main innovation, taking a lead from EU conservation Directives, was to incorporate the concept of favourable condition and its maintenance by implementing conservation policies that are regionally targeted at known constraints in the wider environment. Three criteria were suggested to judge favourable condition: a national abundance target of breeding pairs, national and regional targets for breeding productivity, and regional targets for the extent of suitable habitat which is occupied by breeding pairs. Here we refine these criteria, first to take the national abundance target and use it to set regional targets. Distribution targets were implicitly incorporated by this process because abundance targets were set regionally, with regard to the proportion of known territories which should be occupied. This allowed us to dispense with the distribution criterion as originally proposed. Our next refinement was to base regional demographic targets not only on breeding productivity, but also on indirect measures of survival (which are likely to have more influence on population dynamics). Despite apparent overall population stability over the last 20 years, the national golden eagle population failed to meet the abundance target and only 3 of 16 regions where eagles have occupied territories since 1982 were considered to be in favourable condition. The key constraint preventing favourable condition being met was persecution, predominantly in some areas managed for grouse shooting. The advantages of a conservation framework over similar approaches, such as species action plans, are highlighted.     

Effects of acidic deposition on soil ecosystems under forest in the Chongqing region of China

The effects of acidic deposition on soil ecosystems under temperate coniferous forest in the Chongqing region of China were investigated from 1993 to 1994. Precipitation, throughfall, stemflow, soil solutions, and soil samples were collected to estimate the acidification of soil ecosystems through the changes of their chemical components. The concentrations of ion species in the throughfall and stemflow under masson pine forest in Mt. Zhenwu were higher than those under mixed coniferous forest in Mt. Jinyun and under camphor tree forest in Laojundong, suggesting that Mt. Zhenwu is located in the vicinity of the Chongqing center and that it allowed the canopy of masson pine to intercept air pollutants. However, the level of aluminum dissolution into soil solutions was relatively low under masson pine forest in Mt. Zhenwu in spite of the low pH in the stemflow.     

Changing public interest in,and awareness of,acid deposition: Some evidence from the UK

It is fundamental that the general public have access to usable environmental information on which they can base their decisions. Since 1984 the Atmospheric Research and Information Centre (ARIC) has operated a public information programme for the UK on the subject of acid deposition. The objective of the programme is to disseminate information on acid deposition without advocacy. ARIC provides enquirers with a broad range of authoritative and accurate facts and opinions from a wide range of parties from all sides of the debate. These sources include pressure groups, governmental bodies and industrialists from the UK and overseas. By deconstructing complex technical material and reassembling it for dissemination in a user friendly form, ARIC assists those receiving information to obtain a balanced perspective. This enables personal decision making within the context of the fullest information resource ARIC is able to provide.     

Human impact in the Holocene fluvial and coastal evolution of the Marche region, Central Italy

Today, the coasts of the Marche region are represented by almost continuous rectilinea sand beaches except in the north, at the border with the Romagna region, and in the central part, around the Conero ridge, where there are active rock cliffs. The sandy coasts are protected almost everywhere by artificial barriers built up as a protection against the general tendency to retreat. Along some tracts, the coastal erosion started at the beginning of this century but became generalized after 1940–1950. This was mainly due, first, to the reduction in sediment supply, following the improvement in agricultural techniques after the Italian Unification, and, later, to the widespread extraction of gravels from the thalwegs related to the rapid increase in urban population in the 1950s. However, in the same period, along the rivers, there was a widespread creation of artificial levees to prevent lateral erosion or flooding and to extend areas suitable for agriculture. Following these practices, the lower-middle tracts of the rivers underwent a strong vertical downcutting which increased as a result of the creation of checkdams downvalley of many bridges which contributed to the store of the sediments in the upper part of the valleys. At present, most of the rivers have an irregular course and are deeply entrenched in the bedrock or inside their own sediments.Up to the beginning of the century, most of the lower tracts of the valleys were characterized by strong aggradation in a braidplain system. This aggradation started as early as the Middle Ages (1100 AD) but increased after the Renaissance as a consequence of a generalized deforestation of the Periadriatic Basin and the following severe soil erosion. In the mean time, the coast underwent a very fast progradation, in some places more than 500 m. Small deltas were created at the mouths of the rivers, and longshore bars and sandy beaches began to occupy the base of the active cliffs which previously extended between one river and another. However, in the mountain parts of the river basins, a meander course existed, and in many cases still exists, expecially where the human interventions were of limited extent.Before 1000–1100 AD, all the rivers had a meander pattern and, at the junction with the sea, entered lagoons and swamps in most cases protected by littoral barrier beaches. These conditions were established earlier than the third century BC and have been attributed to the first systematic land clearance and the following soil erosion during the Bronze and Iron Ages. At that time, the regional coastline became almost rectilinear but with many active cliffs between one river and another.Before being affected by a major human impact (earlier than 4000 years BP) the ‘natural’ coastal environment was represented by active rock cliffs which alternated with pocket beaches corresponding to a river mouth. In some rivers, embayments and beaches were located up to 4–5 km inland from the present-day position. After the Flandrian transgression the evidence presented reveals major changes that can be attributed to human impact.     

Integrated assessment of emission control scenarios,including the impact of tropospheric ozone

The RAINS (Regional Air Pollution INformation and Simulation) model was developed at IIASA as an integrated assessment tool to assist policy advisors in evaluating options for reducing acid rain. In recent years, the European implementation of this model has been used to support the negotiations on an updated, effect-based Sulphur Protocol under the Convention on Long-range Transboundary Air Pollution. The development of future strategies for reducing the environmental damage caused by air pollutants requires a multi-pollutant, multi-effect approach. In this context, the RAINS model is being further developed to include ozone. This paper outlines the development of an integrated assessment model for tropospheric ozone, which combines information on the emissions of ozone precursors (NO_x and VOCs), the available control technologies and abatement costs, the formation and transport of ozone and its environmental effects in Europe.     

A summary of the impact of acid rain on atlantic salmon (Salmo salar) in Canada

Within the present North American range of Atlantic salmon, severe acid rain effects are limited to the Southern Upland area of Nova Scotia. In the Southern Upland, long range transport of H₂SO₄ has caused many rivers to decline in pH to the point where their Atlantic salmon stocks have been destroyed or much diminished. Chemical records show a declining pH trend in N.S. rivers since the early 1950s. Eighty % of the annual variation in H⁺ concentration can be accounted for by a multiple linear regression model on excess sulphate, total Al and organic anions. It is technically feasible to restore the acidified salmon habitat by the addition of limestone; the total cost of mounting a liming program to restore the lost habitat has been estimated at $4.75 × 10⁶ yr^?1. The pre-acidification Atlantic salmon production capacity of the Southern Upland was estimated from physical habitat surveys and tag return data to be about 45 000 fish yr^?1. Acidification has caused a 50% decline to the current production level of about 23 000 fish yr^?1. The costs of the liming program, when compared to the economic benefits of the anticipated salmon enhancement, are economically unjustifiable. The eradication of salmon from such large regions will hinder future programs to reestablish the species in their former range when pollution of the atmosphere is eventually brought under control. Present plans are for a small liming program to establish a series of refuges for the preservation of nuclei of native salmon stocks.