To evaluate the acid deposition reduction negotiated for 2010 within the UNECE LRTAP Gothenburg Protocol, sulphur and nitrogen deposition time-series (1880-2100) were compared to critical loads of acidity on five French ecosystems: Massif Central basalt (site 1) and granite (2); Paris Bassin tertiary sands (3); Vosges mountains sandstone (4) and Landes eolian sands (5). The SAFE model was used to estimate the response of soil solution pH and [graphic removed] ratio to the deposition scenario. Among the five sites, critical loads were exceeded in the past at sites 3, 4 and 5. Sites 3 and 4 were still expected to exceed in 2010, the Protocol year. Further reduction of atmospheric deposition, mainly nitrogen, would be needed to achieve recovery on these ecosystems. At sites 3, 4 and 5, the delay between the critical load exceedance and the violation of the critical chemical criterion was estimated to be 10 to 30 years in the top soil and 50 to 90 years in the deeper soil. At site 5, a recovery was expected in the top soil in 2010 with a time lag of 10 years. Unexpectedly, soil pH continued to decrease after 1980 in the deeper soil at sites 2 and 5. This time lag indicated that acidification moved down the soil profile as a consequence of slow base cation depletion by ion exchange. This delayed response of the soil solution was the result of the combination of weathering rates and vegetation uptake but also of the relative ratio between base cation deposition and acid compounds.

Leaching experiments of rebuilt soil columns with two simulated acid rain solutions (pH 4.6-3.8) were conducted for two natural soils and two artificial contaminated soils from Hunan, south-central China, to study effects of acid rain on competitive releases of soil Cd, Cu, and Zn. Distilled water was used in comparison. The results showed that the total releases were Zn>Cu>Cd for the natural soils and Cd>Zn[double greater-than sign]Cu for the contaminated soils, which reflected sensitivity of these metals to acid rain. Leached with different acid rain, about 26-76% of external Cd and 11-68% external Zn were released, but more than 99% of external Cu was adsorbed by the soils, and therefore Cu had a different sorption and desorption pattern from Cd and Zn. Metal releases were obviously correlated with releases of TOC in the leachates, which could be described as an exponential equation. Compared with the natural soils, acid rain not only led to changes in total metal contents, but also in metal fraction distributions in the contaminated soils. More acidified soils had a lower sorption capacity to metals, mostly related to soil properties such as pH, organic matter, soil particles, adsorbed SO₄ ²-, exchangeable Al³⁺ and H⁺, and contents of Fe₂O₃ and Al₂O₃.

Strongly decreasing atmospheric emissions and acidic deposition during the 1990s have initiated chemical reversal from acidification in several drinking-water reservoirs of the Erzgebirge, SE Germany. We studied responses of phytoplankton, zooplankton and fish stocks in five reservoirs and at enclosure scale after experimental neutralization of 1,200 m³ of lake water. About 4 months after this treatment, diatoms and cryptomonads replaced the predominating chrysophytes and dinoflagellates. The colonization by acid-sensitive species of green algae, cryptomonads, rotifers and Cladocera (e.g. Bosmina longirostris) is explained by the occurrence of dormant stages or by survival of individuals in very low abundances. Analogous to the enclosure experiment, three reservoirs showed significantly (p < 0.01) falling trends of chlorophyll a and phytoplankton biovolume, mainly due to the decline of dinoflagellates. Picoplankton and diatoms increased slightly in two reservoirs. The zooplankton communities were dominated by rotifers and small Cladocera. Representatives of the genus Daphnia were lacking. Two reservoirs were re-colonized by zooplanktivorous fish populations of either perch (Perca fluviatilis) or sunbleak (Leucaspius delineatus). The latter exhibited extremely high fluctuating abundance and biomass and even suffered from a population crash. This natural mortality was caused by a limited food supply. Hence, severe top-down control may delay the recovery of larger zooplankton species like daphnids. Fishery management comprising the introduction of predatory fishes can help to control zooplanktivorous fish populations and to prevent their mass mortality.

The aim of presented study was to determine the influence of long-term inundation on the changes in the content of polycyclic aromatic hydrocarbons. Two soils (B, MS) with differentiated properties were selected for the presented study. The experiment was carried out in 5-l containers, irrigated with distilled or post-sewage water for seven days. The study samples were collected directly after the water had been drained and then after seven, 14, 28 and 50 days. In the material collected, the content of polycyclic aromatic hydrocarbons was determined by means of the HPLC-UV method. The soils used for the presented experiment were characterised by differentiated PAH content levels. However, in both soils 28 days after water had been drained, a gradual increase of the PAH sum was noted. This increase was in relation to beginning of the experiment significantly higher in soil MS characterised by a lower PAH content (43% and 86%, respectively in the experiment with distilled and post-sewage water). The range of the PAH sum increase in soil B was from 28% to 38%. After the 28th day of the experiment, a decreasing trend was noted. The trend persisted until the last experimental date. Only in soil B, a decrease in the PAH up to a level close to the PAH level on the onset of the experiment was observed. In soil MS, PAH content on the last experimental date was still 25% (distilled water) and 52% (post-sewage water) higher than at the beginning of the experiment. In control soils (non-flooded), PAH content did not undergo any significant changes during the whole experimental period. In the presented studies, significant relationships between the values of some PAH content levels and Ca²⁺ ions content was noted.

The aim of this study was examination possibility of Azolla caroliniana Willd. to aerate its medium enriched with Cd(II) and Hg(II) and comparison of DO and ODR methods in measurement aeration status of solutions. Azolla system has been chosen to verify the validity of the measuring ODR method in water solution. Water aeration measurements, one of important environmental tests, are performed most often by measurement of dissolved oxygen with oxygen sensors. Other similar method called oxygen diffusion rate is generally used in different porous materials such as soil. Our first objective was to check if these both methods are comparable and may be use exchangeable in water solution. The both types of measurements were performed in medium saturated at different oxygen concentrations. The linear relationship and high correlation (R = 0.89) were found between values of ODR and DO. The object of the second part of our studies was A. caroliniana Willd. (Azollaceae), a floating water fern living in symbiosis with cyanobacterium Anabaena azollae Strasb. (Nostoceae) that fixes atmospheric nitrogen. Azolla plants are used for centuries as a nitrogen biofertilizer. The second aim of our work was to find out, if the fern reduces or increases oxygen concentration in water. The ODR method was used to determine the aeration status of the nutrient solution. During 12 days of the experiment at laboratory conditions, an active role of A. caroliniana in aeration of the nutrient solution containing Cd(II) and Hg(II) was stated.

In order to restore the forest ecosystem in the vicinity of an industrial park, Ulsan, southeastern Korea, which has been heavily acidified by air pollution, a preliminary experiment by applying tolerant plants selected through several procedures, and dolomite and sewage sludge as soil ameliorators was carried out. Furthermore, a restoration based on the results was executed and the effects were evaluated based on the creation of safe sites, where new species can establish: regeneration of the forest with species similar in composition to the natural vegetation of native forests that are distant from the industrial park; increase in species diversity. In a preliminary study, the necessity of soil amelioration was diagnosed. Quercus serrata, Alnus firma and Ligustrum japonicum, which represent for tree, subtree, and shrub layers of vegetation in this region, were used as sample plants. Dolomite, sludge, and a mixture of both materials were applied as soil ameliorators. Bare ground (BG), and two grasslands dominated by forbs (GF) and grass (GG), respectively were designated as experimental plots based on a vegetation map of the corresponding area. BG and GF plots, which have lower organic matter contents, increased the growth of sample plants in response to soil amelioration, whereas that with higher contents, GG plot, did not show this response. The result suggests that necessity of soil amelioration depends on site quality. The effects of soil amelioration depended also on the sample plants. This difference is due to an ecological property of A. firma, which can fix atmospheric nitrogen through a symbiotic relationship with actinomycetic fungi. This result implies that this alder could be used as a substitute for soil ameliorators in restoration plan of this area. The height and standing crop of undergrowth, which forms dense grass mat and thereby impedes establishment of new plants, decreased in the restored stands. Such a decrease in the height and biomass of undergrowth could be recognized as providing safe sites, in which the other plants can invade, by removing the dense carpet formed by Miscanthus sinensis. The results of stand ordination showed a progression of the former bare grounds to either M. sinensis (GG) or Pueraria thunbergiana (GF) stands, suggesting a natural recovery through succession toward the stands dominated by both plants. But the change was not progressed beyond the grassland stage. Active restoration practice, which was carried out by applying tolerant plants, however, led to a change toward species composition similar to the natural vegetation before devastation. Furthermore, restored stands reflected the restoration effect by showing higher diversity than the stands in the degraded state. These results showed that the restorative treatment carried out by introducing tolerant plants functioned toward increasing both biological integrity and ecological stability and thereby could meet the restoration goal.

The sorption of hydrophobic organic pollutants on soils or sediments has been widely studied. However, more attention in the previous studies has been paid to sorption mechanism and effects of relevant environmental factors, few studies were reported on effects of heavy metals on the sorption of hydrophobic organic pollutants. In this paper, sorption of phthalate esters (diethyl phthalate, DEP, and di-n-butyl phthalate, DnBP) and copper on the Yellow River sediment was investigated with particular attention to the effects of copper on the phthalate sorption. The experimental results show that the sorption isotherms of phthalates could be reasonably described by the Freundlich equation. Higher sorption equilibrium constant was obtained for DnBP due to its greater hydrophobicity. The existence of copper would enhance the sorption of DnBP. Moreover, strong sorption of copper to sediment were found and attributed to abundant carbonates in the Yellow River sediment. After carbonates were removed, notable effects of copper on the phthalate sorption were observed due to the decrease of copper sorption and the increase of aqueous copper concentration. With 153 mg l-¹ copper added, the partition coefficient decreases by 52% for DEP and increases by 79% for DnBP. Primary factors that may influence interaction between the sorption of copper and DEP and DnBP were also investigated, such as complexation between copper and phthalate, and phthalate hydrophobicity. The complexation between phthalate esters and copper was substantiated by polarogram and fluorescence spectrograph, and the calculated mol ratio of complexation (copper : phthalate) was found to be 2:1.

Fluvial bed sediments are widely used for characterizing anthropogenic contaminant signals in urban watersheds. This study presents the first preliminary examination of sequentially extracted Pb from grain size fractionated bed sediments using the optimized (standardized) BCR procedure. Baseline sediment samples and samples from the vicinity of three storm-sewer outlets in Nuuanu Stream, Honolulu, Hawaii, were examined. The weighted average Pb liberated from four sequentially extracted phases was 144 ± 26 mg/kg (±SD). These Pb concentrations are high compared to 3 mg/kg leached by a 0.5 M HCl solution, and 13 mg/kg from a 4-acid total digestion of baseline sediments. Over a 1.8 km section of stream channel, land use variations and traffic density differences had little impact on the magnitude of Pb in specific phases for each of the six grain size fractions examined. Regardless of grain size or spatial location, Pb in the reducible phase exceeded that in oxidizable, residual and acid extractable phases. Weighted reducible Pb concentrations for three sewer outlet sites ranged from 69 to 92 mg/kg, and this phase typically accounted for 70-80% of all labile Pb. The <63 μm grain size class did not exhibit the highest Pb concentration, instead this was found in either the 125-250 μm or 500-1,000 μm fractions. Examining bed sediment phase associations of Pb over a smaller length dimension (i.e., 40 m) centered around one sewer outlet, indicated higher concentrations at the outlet (180 mg/kg) compared to upstream (132 mg/kg) or downstream (150 mg/kg). The differences were primarily associated with higher Pb concentrations in the reducible and oxidizable phases of the coarse sand fractions (500-2,000 μm) at the outlet. Overall, all data point to a significant anthropogenic signal for Pb in bed sediments in the urbanized section of Nuuanu Stream.

A powerful 7.3 magnitude earthquake struck Taiwan on September 21, 1999. The stream water chemistry (pH, total alkalinity, conductivity, sodium, potassium, calcium, magnesium, ammonium, fluoride, chloride, sulfate, and nitrate) has been monitored since 1995 at the Guandaushi forestry riparian zone in central Taiwan. Collected data was used as a basis for comparing pre- and post-earthquake impacts. The pH, conductivity, and concentrations of Na, Ca, Mg, SO₄, and HCO₃ in stream water were lowest during the summer season, when stream water discharge was highest. On the other hand, the lowest concentrations of Cl, NH₄, and NO₃ in stream water occurred during the winter season, when stream water discharge was lowest. Also, K and F showed very little seasonal fluctuation in concentration. Downward trends in K and Ca were found 14 months prior to the earthquake; although, an upward trend occurred in NH₄ at the same time.

Ammonia fluxes from application of anaerobically-digested slurry (ADS) and chemical fertilizer (CF) to flooded forage rice (Oryza sativa L.) in Japan were measured using a dynamic flow-through chamber method in lysimeters. The CF was applied at a rate of 300 N ha-¹ (three times) as ammoniacal-N fertilizer, and the ADS was applied to the lysimeters at total rates equivalent to 75, 100 and 150 kg N ha-¹, by broadcasting uniformly into the floodwater at three or six times (equal splits) between 17th June and 17th November, 2005. The emission fluxes for the first 2 days after application were very high from ADS, the highest values being 679 compared with a maximum of 156 mg N m-² d-¹ from CF. Most (61-93%) of the ammonia loss occurred during the first 5 days after each application of fertilizer. The total N loss as ammonia from ADS (29.6-51.7%) was much higher than from CF (12.2%). The highest fluxes were observed in August (2005) when air temperature was highest. More ammonia was lost from the ADS applied at the early stages (i.e. root taking, tiller stages) than at later stages (i.e. elongation, fruiting stages) of rice growth.