Defoliation is one of the most important parameters monitored in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). Defoliation is an indicator for forest health and vitality. Conventional statistical analysis shows weak or not significant correlations between tree crown defoliation and climatic conditions or air pollution parameters, because of its high variability. The study aims to evaluate the most important factors among climatic, pollutants (Nₒₓ and NHy) and stand parameters affecting crown defoliation of the main European tree species (Fagus sylvatica, Picea abies, Quercus ilex, Pinus sylvestris and Quercus petraea) through application of a new and powerful statistical classifier, the random forests analysis (RFA). RFA highlighted that tree crown defoliation was mainly related to age in P. abies, to geographic location in F. sylvatica and to air pollution predictors in Q. ilex, while it was similarly linked to meteorological and air pollution predictors in P. sylvestris and Q. petraea. In this study, RFA has proven to be, for the first time, a useful tool to discern the most important predictors affecting tree crown defoliation, and consequently, it can be used for an appropriate forest management.

Defoliation is one of the most important parameters monitored in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests). Defoliation is an indicator for forest health and vitality. Conventional statistical analysis shows weak or not significant correlations between tree crown defoliation and climatic conditions or air pollution parameters, because of its high variability. The study aims to evaluate the most important factors among climatic, pollutants (Nox and NHy) and stand parameters affecting crown defoliation of the main European tree species (Fagus sylvatica, Picea abies, Quercus ilex, Pinus sylvestris and Quercus petraea) through application of a new and powerful statistical classifier, the random forests analysis (RFA). RFA highlighted that tree crown defoliation was mainly related to age in P. abies, to geographic location in F. sylvatica and to air pollution predictors in Q. ilex, while it was similarly linked to meteorological and air pollution predictors in P. sylvestris and Q. petraea. In this study, RFA has proven to be, for the first time, a useful tool to discern the most important predictors affecting tree crown defoliation, and consequently, it can be used for an appropriate forest management.

In an effort to customize biochars for soil amendments, multiple feedstocks have been combined in various ratios prior to pyrolysis. The resulting variation in the chemistry and structure can affect a biochar’s adsorption capacity, which influences the bioavailability of many chemical compounds in the soil system including phenolic acids. This study characterizes the sorption of 14C-labeled ferulic acid, syringic acid, and chlorocatechol to four biochars prepared from individual feedstocks and four from mixed feedstocks using batch equilibration. Pure feedstock biochar sorption followed switchgrass< swine solids< poultry litter< pine chip for both ferulic (Kd= 1.4-75) and syringic acid (Kd= 0.07-6.03), and appeared to be influenced by the properties of the biochars as well as the chemicals themselves. All biochar Kd values, except pine chip, were lower than that of the reference soil (Waukegan silt loam). The sorptive properties of the combined feedstock biochars could not be predicted from their pure feedstock components and sorption coefficients were both unexpectedly higher and lower than the individual parent materials’ biochars. Further research is necessary to understand the characteristics of these combination biochars, particularly their sorption, which this study has shown is not merely an intermediary of its components.

9 páginas.-- 2 figuras.-- 2 tablas.-- 60 referencias.-- (Artículo en prensa) | In an effort to customize biochars for soil amendments, multiple feedstocks have been combined in various ratios prior to pyrolysis at 350 °C. The resulting variation in the chemistry and structure can affect the adsorption capacity of biochar and thus influence the bioavailability of many chemical compounds in the soil system including phenolic acids. This study examines the sorption of 14C-labeled ferulic acid, syringic acid, and chlorocatechol to four biochars prepared from individual feedstocks and four biochars produced from mixed feedstocks using batch equilibration. Pure feedstock biochar sorption followed switchgrass < swine solids < poultry litter < pine chip for both ferulic (Kd = 1.4-75 L kg-1) and syringic acid (Kd = 0.07-6.03 L kg-1). Sorption appeared to be influenced by the properties of the biochars as well as the structure of the chemicals. All biochar Kd values, except pine chip, were consistently lower than that of the reference silt loam soil. The sorptive properties of biochars produced from combined feedstocks could not be predicted from their pure feedstock components, and sorption coefficients were both higher and lower than the individual parent materials' biochars. Further research is necessary to understand the characteristics of these combination biochars, particularly their sorption, which this study has shown is not merely an average of its components | Peer reviewed

Potential toxic elements (PTEs) concentration was analyzed seasonally in seawater and sediment samples from Tuticorin coast, India. The extent of PTEs contamination in Tuticorin coast has been revealed by measuring the concentrations of iron (Fe), nickel (Ni), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) using inductively coupled plasma mass spectrophotometer (ICP-MS) seasonally. The concentration of all the PTEs in seawater samples was higher in summer and least in spring. The concentration of all the PTEs was significantly different within and among the season except for Zn and Cu. The concentration of PTEs in sediment samples was higher in winter and least in summer seasons. Exceptionally, the concentration of Cd was not significant among and within the seasons. The concentration of the PTEs in seawater and sediment samples exceeded the WHO-recommended limits. The contamination factor (CF) and geoaccumulation index (I gₑₒ) values indicated significant contamination of PTEs in the sediment samples collected in different seasons. Variations in the concentration of PTEs could be due to changes in levels of pollution discharge over time, availability of PTEs for adsorption, as well as variations in the sampling season. The presence of a number of industries surrounding the Tuticorin coast and the release of the effluents from both industries and domestic sources are the main source of pollution at Tuticorin coast and are the prime reasons for the loss of existing diverse ecosystem.

Potential toxic elements (PTEs) concentration was analyzed seasonally in seawater and sediment samplesfromTuticorincoast,India.TheextentofPTEs contamination in Tuticorin coast has been revealed by measuring the concentrations of iron (Fe), nickel (Ni), zinc (Zn), copper (Cu), cadmium (Cd), and lead (Pb) using inductively coupled plasma mass spectrophotometer (ICP-MS) seasonally. The concentration of all the PTEs in seawater samples was higher in summer and least in spring. The concentration of all the PTEs was significantly different within and among the season except for Zn and Cu. The concentration of PTEs in sediment samples was higher in winter and least in summer seasons. Exceptionally, the concentration of Cd was not significant among and within the seasons. TheconcentrationofthePTEsinseawaterandsediment samples exceeded the WHO-recommended limits. The contamination factor (CF) and geoaccumulation index (Igeo) values indicated significant contamination of PTEs in the sediment samples collected in different seasons. Variations in the concentration of PTEs could be due to changes in levels of pollution discharge over time, availability of PTEs for adsorption, as well as variations in the sampling season. The presence of a number of industries surrounding the Tuticorin coast and the release of the effluents from both industries and domestic sources are the main source of pollution at Tuticorin coast and are the prime reasons for the loss of existing diverse ecosystem.

In the Mezquital valley, untreated wastewater (45 m³ s⁻¹) from Mexico City is used for the irrigation of around 900 km²of agricultural soil. High concentrations of metals including methylmercury (3.8 ± 2.5 ng l⁻¹) and lead (0.16 ± 0.05 mg l⁻¹) were measured in anoxic wastewater canals. Downstream, dissolved, and particulate polymetallic (Hg, Pb, Cr…) concentrations decreased by factors 10 to 1,000 in the Tula River (which received a mix of fresh and wastewater) due to the dilution and oxidation of surface water, and to the decrease of contaminants concentration in wastewater downstream irrigated soils. However, dissolved and particulate methylmercury concentrations (0.06 to 0.33 ng l⁻¹and 1.6 to 4.5 μg kg⁻¹, respectively) remained elevated in comparison to other natural hydrosystems. The monitoring of an irrigation event and the distribution of metals in a soil profile irrigated for more than 80 years showed that metals were retained in the draining tilled layer. The oxic conditions and slightly acidic pH (~6.5) in this layer were found favorable for metal adsorption and co-precipitation with redox-sensitive elements (Fe, Mn) and suggestively for mercury demethylation. In the downstream Tula River and groundwater, almost all metallic concentrations remained below guideline thresholds. Only, dissolved As and Pb concentrations remained two to five times above thresholds for drinking water, highlighting a potential health risk for approximately 500,000 people who use groundwater as water supply.

In the Mezquital valley, untreated wastewater (45 m(3) s(-1)) from Mexico City is used for the irrigation of around 900 km(2) of agricultural soil. High concentrations of metals including methylmercury (3.8+/-2.5 ng l(-1)) and lead (0.16+/-0.05 mg l(-1)) were measured in anoxic wastewater canals. Downstream, dissolved, and particulate polymetallic (Hg, Pb, Cr.) concentrations decreased by factors 10 to 1,000 in the Tula River (which received a mix of fresh and wastewater) due to the dilution and oxidation of surface water, and to the decrease of contaminants concentration in wastewater downstream irrigated soils. However, dissolved and particulate methylmercury concentrations (0.06 to 0.33 ng l(-1) and 1.6 to 4.5 g kg(-1), respectively) remained elevated in comparison to other natural hydrosystems. The monitoring of an irrigation event and the distribution of metals in a soil profile irrigated for more than 80 years showed that metals were retained in the draining tilled layer. The oxic conditions and slightly acidic pH (similar to 6.5) in this layer were found favorable for metal adsorption and co-precipitation with redox-sensitive elements (Fe, Mn) and suggestively for mercury demethylation. In the downstream Tula River and groundwater, almost all metallic concentrations remained below guideline thresholds. Only, dissolved As and Pb concentrations remained two to five times above thresholds for drinking water, highlighting a potential health risk for approximately 500,000 people who use groundwater as water supply.

In recent years, there has been the phenomena of spruce dieback in Europe. Significant areas of spruce low mortality now cover both sides of the Polish southern border. We evaluated ecochemical parameters influencing the heavy dieback occurring in mature spruce stands in the Polish Carpathian Mountains. Dolomite, magnesite and serpentinite fertilizers were applied to experimental plots located in 100-year-old stands in the autumn of 2008. The experimental plots were located in the mid-elevational forest zone (900–950 m) on two nappes of the flysch Carpathians: Magura (Ujsoły Forest District) and Silesian (Wisła Forest District). The saturation of the studied soils demonstrates moderate resilience of soils in Wisła Forest District in relation to acid load and high flexibility of the Ujsoły soils. After application of the fertilizers, an increase of Mg, Ca and Mb was noted in the soil solution, determined in the overlaying highly acidic organic horizons through the ion-exchange buffering mechanism of highly protonated functional groups with high buffering capacity. Magnesium concentration increased following fertilization, presenting a potential improvement of forest growth capacity without the hazard of adverse side effects of liming. Aluminium stress in old spruce is unlikely, while trees in the control plots in Wisła Forest District may already be sensitive to aluminium stress. Serpentinite fertilization improved the supply of soils in magnesium without causing significant changes in the pH of the soil. Such changes in the pH were found in dolomite and magnesite fertilizer.

In recent years, there has been the phenomena of spruce dieback in Europe. Significant areas of spruce low mortality now cover both sides of the Polish southern border. We evaluated ecochemical parameters influencing the heavy dieback occurring in mature spruce stands in the Polish Carpathian Mountains. Dolomite, magnesite and serpentinite fertilizers were applied to experimental plots located in 100-year-old stands in the autumn of 2008. The experimental plots were located in the mid-elevational forest zone (900– 950 m) on two nappes of the flysch Carpathians: Magura (Ujsoły Forest District) and Silesian (Wisła Forest District). The saturation of the studied soils demonstrates moderate resilience of soils in Wisła Forest District in relation to acid load and high flexibility of the Ujsoły soils. After application of the fertilizers, an increase of Mg, Ca and Mb was noted in the soil solution, determined in the overlaying highly acidic organic horizons through the ion-exchange buffering mechanism of highly protonated functional groups with high buffering capacity. Magnesium concentration increased following fertilization, presenting a potential improvement of forest growth capacity without the hazard of adverse side effects of liming. Aluminium stress in old spruce is unlikely, while trees in the control plots in Wisła Forest District may already be sensitive to aluminium stress. Serpentinite fertilization improved the supply of soils in magnesium without causing significant changes in the pH of the soil. Such changes in the pH were found in dolomite and magnesite fertilizer. | Ecochemical indicators, Slow release fertilizers, Old Picea abies stands, Poland | 25 | 1-17 | 1971