The present study was conducted in tropical Sal forest ecosystem of the Doon valley in the Indian Himalayas to assess the critical load of sulfur and nitrogen and their exceedances. The observed pattern of throughfall ionic composition in the study are Ca2+>K+>Mg2+>Cl−> HCO3−> Na+>NO3 −> SO3 2−≥ NH4 +>F−. The sum of cation studied is 412.29 μeq l−1 and that of anions is 196.98 μeq l−1, showing cation excess of 215.31 μeq l−1. The cations, namely Ca2+, Mg2+, K+, Na+, and NH4 +, made a contribution of about 67% of the total ion strength, where as anion comprising of SO4 2−, Cl−, NO3 −, and HCO3 − contributed 33%. The chief acidic components were Cl– (12%) and HCO3 − (8%), while the presence of SO4 2− (5%) and NO3 − (6%), respectively. Percentage contribution of bole to total aboveground biomass was ∼72.38% in comparison to 2.24–2.93% of leaf biomass, 10.34–10.96% of branch biomass and 13.21–17.07% of bark biomass. There was high and significant variation (P < 0.001) in the total aboveground biomass produced at different sites. The aboveground net primary productivity (ANPP) in these sites ranged between 2.09 and 9.22 t ha−1 year−1. The base cations and nitrogen immobilization was found to be maximum in bole. The net annual uptake of the base cations varied from 306.85 to 1,311.46 eq ha−1 year−1 and of nitrogen from 68.27 to 263.51 eq ha−1 year−1. The critical appraisal of soil showed that cation exchange capacity lied between 18.37 and 10.30 Cmol (p+) kg−1. The base saturation percentage of soil was as high as 82.43% in Senkot, whereas in Kalusidh it was just 44.28%. The local temperature corrected base cation weathering rates based on soil mineralogy, parent material class, and texture class varied from 484.15 to 627.25 eq ha−1 year−1, showing a weak potentiality of the system to buffer any incoming acidity and thus providing restricted acid neutralizing capacity to keep the ecosystem stable under increased future deposition scenarios in near future. The appreciable BS of the soil indicates the presence of intense nutrient phytorecycling forces within this climate and atmospheric deposition in replenishing base cations in the soil, which includes intrinsic soil-forming processes, i.e., weathering. The highest value of critical load for acidity was 2,896.50 eq ha−1 year−1 and the lowest was 2,792.45 eq ha−1 year−1. The calculated value of the minimum critical loads for nitrogen varied from 69.77 to 265.01 eq ha−1 year−1, whereas the maximum nitrogen critical load ranged between 2,992.63 and 4,394.45 eq ha−1 year−1. The minimum and the maximum critical loads of sulfur ranged between 2,130.49 and 3,261.64 eq ha−1 year−1 and 2,250.58 and 3,381.73 eq ha−1 year−1, respectively. The values of exceedance of sulfur and nitrogen were negative, implying that in the current scenario Sal forests of the Doon valley are well protected from acidification.

Polycyclic aromatic hydrocarbons (PAH) have been identified and quantified in dated layers of freshwater and marine sediments in Norway. Furthermore, profiles of the individual PAH (22 different) have been used to evaluate possible PAH sources. There is a significant increase in total PAH levels (sum of the 22 PAH) in freshwater sediments from the south-western part of Norway representing the 1800–1950 period, whereas the concentrations have decreased with a factor of approximately four since the 1950s. This pronounced trend was observed in two independent surveys. In northern Norway, the PAH levels in lake sediments have increased slightly during the past decades. In spite of this, the levels are considerably lower than in lake sediments from the south-western part of Norway. In fact, the PAH levels are decreasing northwards on the Norwegian mainland for both freshwater and marine surface sediments. Generally, the regional total PAH levels are higher (three to four times) in freshwater sites compared to the corresponding marine sites. Results of PAH source allocation indicate that pyrogenic sources are important in almost all sediment samples studied. Sediment samples were also collected at Svalbard where the local coal reserve is the major contributor to PAH.

The objective of this study was to develop an index of biological integrity (IBI) for national-level monitoring of watersheds as an ecosystem health assessment methodology for the South Korean government. A 10-metric IBI model (IBIKW) was developed for watershed management and then applied to 76 streams in four major watersheds in Korea. The model assessments showed that 32.9% of all streams were judged to be in ‘excellent–good’ condition, whereas 67.1% were in ‘fair–poor’ condition, indicating severely impaired ecological health. Nutrient analyses of stream water revealed a two- to fivefold increase in nutrient and biological oxygen demand (BOD) levels in urban- and cropland-dominant streams compared to forest-dominant streams. The guild structure within the watersheds indicated that tolerant species were predominant in severely degraded regions (BOD > 6 mg L−1), and sensitive species were distributed in regions with BOD < 2 mg L−1. Factors affecting ecosystem health (IBIKW scores) included chemical water quality parameters, physical habitat parameters and land use around the stream. In particular, land use was one of the major factors influencing ecosystem health, as indicated by the strong relationships between the percentages of urban and forest streams and the IBIKW scores. The integrated ecosystem health assessment technique developed here can be applied for both regular bioassessments and post-restoration assessments.

The influence of watershed land use on microzooplankton was examined. Six rivers and a shallow lake located in rural (agriculture, livestock) and urban areas were sampled during 4 weeks at low water, low temperatures and 3 weeks at high water, high temperatures. The major aim of this study was to analyze the composition, richness and abundance of the microzooplankton in relation to land use, taking into account nutrient concentration, biological oxygen demand (BOD5), conductivity, pH, transparency, dissolved oxygen, and chlorophyll-a. Redundancy analysis was used to assess microzooplankton response to environmental gradients. The composition and abundance can be considered good indicators of the land used and characteristic of the basin (broad range of conductivity water). The species composition show a gradient along the conductivity, pH and chlorophyll-a. Brachionus spp. were associated with saline waters on rural area and Keratella spp. (except Keratella tropica) were associated with urban water bodies. The microzooplankton abundance diminished by a factor of ten from the rivers in livestock–agriculture-dominated watersheds to those located in strictly urban areas. Urban rivers had low abundances of chlorophyll-a and microzooplankton despite the high concentration of nutrients. However, the effect of urbanization (mesotrophic/mesosaprobious state and lead presence) cannot be analyzed alone due to the potential effect of a filter-feeding invasive mollusk that colonizes the hard surfaces of harbor buildings and bridge pillars.

The wide-ranging impacts of globally increasing carbon dioxide (CO2) concentration and rising metal-contaminated soils are serious problems in terrestrial ecosystems. In this study, we investigated the effects of elevated CO2 on the lead (Pb) uptake of pine seedlings and the microbial activity in Pb-contaminated soil. Three-year-old pine seedlings were exposed to ambient, as well as elevated levels of CO2 (380 and 760 ppmv, respectively) in 500 mg/kg Pb-contaminated soil. Growth rates, C/N ratios and Pb uptake of the pine seedlings were determined. Dissolved organic carbon (DOC) content and microbial activity were also measured in the rhizosphere soil. Elevated CO2 significantly increased the total biomass and accumulation of Pb in roots and shoots. In addition, the accumulation of Pb in the roots under elevated CO2 concentration was four times higher than those in the roots under ambient CO2 concentration. Elevated CO2 levels also affected C/N ratios in the pine seedlings and soil enzyme activities. Decline in the overall nitrogen content and increases in the C/N ratios of pine needles were observed. Soil enzyme activity increased in the rhizosphere soils, including those of β-glucosidases, N-acetylglucosaminidases, and phosphatases. Quality of the DOC was affected by elevated CO2, while the quantity of DOC was affected by Pb additions under elevated CO2 conditions. Two major conclusions can be drawn from this study: (1) elevated CO2 significantly increased biomass and metal uptake of pine seedlings and (2) chemical metabolism on pine tissue and processes of organic decomposition were more affected by elevated CO2 levels than by Pb contamination.

The concentrations of Hg, Cu, Pb, Cd, and Zn accumulated by regional macrophytes were investigated in three tropical wetlands in Colombia. The studied wetlands presented different degrees of metal contamination. Cu and Zn presented the highest concentrations in sediment. Metal accumulation by plants differed among species, sites, and tissues. Metals accumulated in macrophytes were mostly accumulated in root tissues, suggesting an exclusion strategy for metal tolerance. An exception was Hg, which was accumulated mainly in leaves. The ranges of mean metal concentrations were 0.035–0.953 mg g−1 Hg, 6.5–250.3 mg g−1 Cu, 0.059–0.245 mg g−1 Pb, 0.004–0.066 mg g−1 Cd, and 31.8−363.1 mg g−1 Zn in roots and 0.033–0.888 mg g−1 Hg, 2.2–70.7 mg g−1 Cu, 0.005–0.086 mg g−1 Pb, 0.001–0.03 mg g−1 Cd, and 12.6–140.4 mg g−1 Zn in leaves. The scarce correlations registered between metal concentration in sediment and plant tissues indicate that metal concentrations in plants depend on several factors rather than on sediment concentration only. However, when Cu and Zn sediment concentrations increased, these metal concentrations in tissues also increased in Eichhornia crassipes, Ludwigia helminthorriza, and Polygonum punctatum. These species could be proposed as Cu and Zn phytoremediators. Even though macrophytes are important metal accumulators in wetlands, sediment is the main metal compartment due to the fact that its total mass is greater than the corresponding plant biomass in a given area.

Sulphuric acid-modified bagasse has been used as low-cost adsorbent for the removal of methylene blue (MB) dye from aqueous solution. In order to remove organic compounds that contribute to chemical oxygen demand (COD), pretreatment with thorough washing of adsorbent using boiling distilled water was performed instead of conventional washing using distilled water at room temperature only. This has resulted in the highest efficiency of color removal of 99.45% and COD reduction of 99.36% for MB dye solution at pH 9. Effects of initial pH, dye concentration, adsorbent dosage, temperature, and contact time have been studied. The adsorption of MB dye was pH dependent. Langmuir and Freundlich isotherm models were tested on the adsorption data. The kinetic experimental data were analyzed using pseudo-first order, pseudo-second order, and the intraparticle diffusion model in order to examine the adsorption mechanisms. The adsorption process followed the Langmuir isotherm as well as the Freundlich isotherm and pseudo-second-order kinetic model. The process was found to be endothermic in nature.

A spatially, temporally and chemically resolved emission inventory for particulate matter and gaseous species from anthropogenic and natural sources was created for the Greater Athens Area (GAA; base year, 2007). Anthropogenic sources considered in this study include combustion (industrial, non-industrial, commercial and residential), industrial production, transportation, agriculture, waste treatment and solvent use. The annual gaseous pollutants (ΝΟx, SOx, non-methane volatile organic compounds (NMVOCs), CO and ΝΗ3) and particulate matter (PM2.5 and PM2.5–10) emissions were derived from the UNECE/EMEP database for most source sectors (SNAP 1–9; 50 × 50 km2) and their spatial resolution was increased using surrogate spatial datasets (land cover, population density, location and emissions of large point sources, emission weighting factors for the GAA; 1 × 1 km2). The emissions were then temporally disaggregated in order to provide hourly emissions for atmospheric pollution modelling using monthly, daily and hourly disintegration coefficients, and additionally the chemical speciation of size-segregated particles and NMVOCs emissions was performed. Emissions from agriculture (SNAP 10) and natural emissions of particulate matter from the soil (by wind erosion) and the sea surface and of biogenic gaseous pollutants from vegetation were also estimated. During 2007 the anthropogenic emissions of CO, SOx, NOx, NMVOCs, NH3, PM2.5 and PM2.5–10 from the GAA were 151,150, 57,086, 68,008, 38,270, 2,219, 9,026 and 3,896 Mg, respectively. It was found that road transport was the major source for CO (73.3%), NMVOCs (31.6%) and NOx (35.3%) emissions in the area. Another important source for NOx emissions was other mobile sources and machinery (23.1%). Combustion for energy production and transformation industries was the major source for SOx (38.5%), industrial combustion for anthropogenic PM2.5–10 emissions (59.5%), whereas non-industrial combustion was the major source of PM2.5 emissions (49.6%). Agriculture was the primary NH3 source in the area (72.1%). Natural vegetation was found to be an important source of VOCs in the area which accounted for approximately the 5% of total VOCs emitted from GAA on a typical winter day. The contribution of sea-salt particles to the emissions of PM2.5 was rather small, whereas the emissions of resuspended dust particles exceeded by far the emissions of PM2.5 and PM2.5–10 from all anthropogenic sources.

In this study, the effects of industrial and urban pollution on Pb, Al, Cd, Cu, and Zn accumulation, peroxidase activity, and pigment and protein contents were investigated in shrub and tree leaves in Antakya, Turkey. We determined that industrial and traffic activities produce the most plant-incorporated air pollutants in Antakya City. Cu and Al amounts were high in plants in the urban street location and Cd, Pb, and Zn amounts where high for all plants in the industrial site. Acer negundo L. showed maximum Pb and Zn accumulation at the industrial site and Al accumulation for the urban street site. Higher Cd and Cu amounts were detected in Platanus orientalis L. and Nerium oleander L. in the industrial and urban street sites, respectively. Compared to the control site, decreases in pigment and total soluble protein contents and increases in peroxidase enzyme activity were more evident in industrial and urban street sites. Our results indicated that industry and urban air pollution is high in Antakya City and Pb pollution was at an especially alarming level for vegetation and human health.