The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Perou Catchment (12 km(2)) characterized by heavy rainfall (5686 mm year(-1)). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009-2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Perou Catchment (3400 mu g kg(-1)) than in the entire banana cropping area in Guadeloupe (2100 mu g kg(-1)). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha(-1)), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha(-1)); and the greatest stocks are observed in SC2 on Andosols (12 kg ha(-1)) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Perou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river.rights reserved.

Olive oil production generates a large amount of olive mill wastewater (OMW), the most difficult to treat of agro-industrial effluents. Spreading of OMW across the soilscape has become the most frequently used practice in several Mediterranean basin countries but is hotly debated because of its potential to impair soil environs. The research hypothesis states that soil deterioration is correlated strongly with the spatiotemporal rate of OMW application; thus, the spatial pattern of the soil attributes should be established in conjunction with the rate of OMW spreading. The spatial pattern was ascertained using proximal soil sensing that measures the apparent electrical conductance (ECₐ). Eight representative locations were identified using grouping analysis of the ECₐ data. The soils were analyzed for selected physical and chemical attributes known to be affected by OMW spreading as well as ancillary parameters needed for the calibration of the ECₐ. Discriminant analysis successfully categorized 76% of the ECₐ groups, selecting CEC, sand, pH, and ESP as the most powerful discriminatory variables in the grouping analysis. The correlation coefficients between the measured ECₐ, and the calculated ECₐ, and soil moisture were very high (r > 0.77, P < 0.05), suggesting that the proximal soil survey results are well calibrated. The spreading of untreated OMW over more than 7 years did not impair the soils under study. No significant changes in soil chemo-physical properties such as pH (< 7.66), electrical conductivity in saturated paste (< 3.58 dS m⁻¹), sodium adsorption ratio (< 2.3), potassium adsorption ratio (< 0.33), exchangeable sodium percentage (< 3.85%), and unsaturated hydraulic conductivity (< 0.3 cm h⁻¹) were found in comparison with untreated soils. The results support the premise that moderate quantities of OMW (50–70 m³ ha⁻¹ year⁻¹) equally spread over the soilscape will have little impact on soil health.

We studied the effects of N deposition (0, 10, 20 and 50 kg N ha⁻¹ year⁻¹) on cover and physiology of Pleurochaete squarrosa, a terricolous moss from semiarid Mediterranean ecosystems. We also investigated the effects of N fertilization under competition with vascular plants or under water stress. Under greenhouse conditions, vascular plant competition reduced moss cover, and there was a significant interaction between N and competition. Water stress reduced moss cover under high and low competition conditions. Nitrogen fertilization increased moss cover irrespectively of the N dose supplied at low competition conditions. Under field conditions, N deposition affected moss physiology but not cover. Most of the physiological variables analyzed responded to N deposition, although the response of some of them was saturated with only 10 kg N ha⁻¹ year⁻¹ over the background (nitrate reductase; phosphomonoesterase; tissue N and K⁺). The response of indicators such as chlorophyll a and lutein contents did not show any evidence of saturation, which probably makes them the best candidates in monitoring programs. Based on the data provided, the applicability of the phosphomonoesterase can also be considered. In addition, the importance of taking into account the existence of superimposed environmental gradients (such as those in soil mineral N content) interacting with the response of P. squarrosa to predict impacts of N deposition has been demonstrated. Therefore, detailed soil surveys and integrative physiological evaluations will be required to produce a significantly better picture of the effects of N deposition on Mediterranean ecosystems along extant N deposition gradients.

Mining activities generate spoils and effluents with extremely high metal concentrations of heavy metals that might have adverse effects on ecosystems and human health. Therefore, information on soil and plant metal concentrations is needed to assess the severity of the pollution and develop a strategy for soil reclamation such as phytoremediation. Here, we studied soils and vegetation in three heavily contaminated sites with potential toxic metals and metalloids (Zn, Pb, Cd, As, TI) in the mining district of Les Malines in the Languedoc region (southern France). Extremely high concentrations were found at different places such as the Les Aviniéres tailing basins (up to 160,000 mg kg–1 Zn, 90,000 mg kg–1 Pb, 9,700 mg kg–1 of As and 245 mg kg–1 of Tl) near a former furnace. Metal contamination extended several kilometres away from the mine sites probably because of the transport of toxic mining residues by wind and water. Spontaneous vegetation growing on the three mine sites was highly diversified and included 116 plant species. The vegetation cover consisted of species also found in non-contaminated soils, some of which have been shown to be metal-tolerant ecotypes (Festuca arvernensis, Koeleria vallesiana and Armeria arenaria) and several Zn, Cd and Tl hyperaccumulators such as Anthyllis vulneraria, Thlaspi caerulescens, Iberis intermedia and Silene latifolia. This latter species was highlighted as a new thallium hyperaccumulator, accumulating nearly 1,500 mg kg–1. These species represent a patrimonial interest for their potential use for the phytoremediation of toxic metal-polluted areas.

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 0-20 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.

This study is close to an earlier urban soil survey carried out for a rapidly growing city with a high traffic density in Aurangabad city, India. Consequently, it aims to use the environmental magnetism approach to assess roadside emissions at a known polluted site. Magnetic measurements have been successfully implemented in soil studies and seem to be a suitable approach for pollution assessment in industrial and roadside areas of the study area. The present study was accomplished for magnetic susceptibility, isothermal remanent magnetization, coercivity, hysteresis measurements, thermomagnetic curves, scanning electron microscopy, and energy-dispersive spectroscopy analysis to evaluate the absolute fraction of magnetic minerals in bulk soil samples. The soils displayed variation in magnetic susceptibility values, which was influenced by concentration, domain states, and morphological characteristics of magnetic minerals. Substantial variation in the mineralogical composition of soils deriving from different industrial activities was noticed. The results indicate that industrial and roadside soil samples with mostly coarser and irregular-shaped show ferrimagnetic minerals. The presence of iron–titanium combination in most of the samples is due to titanomagnetite accompanying the titanium-bearing grains. In soils, a higher amount of ferrimagnetic minerals (magnetite, titanomagnetite, maghemite) with a minor content of antiferromagnetic minerals (hematite/goethite) was noticed. These studies reveal that magnetic and morphological characterization of soils can be used as an appropriate tracer for industrial and roadside soil pollution, which leads to new avenues for more detailed chemical mapping.

The objectives of this study were to assess susceptibility to acidification and nitrogen (N) saturation caused by atmospheric deposition to northeastern US forests, evaluate the benefits and shortcomings of making critical load assessments using regional data, and assess the relationship between expected risk (exceedance) and forest health. We calculated the critical loads of nutrient N and of sulfur (S) + N using the steady-state mass balance method at >4,000 regional and national vegetation and soil monitoring network plots in the northeastern USA. Regional calculations of critical loads necessitate use of soil maps which provide a range for each soil characteristic resulting in a broad range of critical load of S + N and exceedance values. For the scenario most representative of regional conditions, over 80 % of the critical loads fell into the range of 850–2050 eq ha⁻¹ yr⁻¹; at 45 % of the plots, deposition exceeded the critical load. In contrast, the critical load for nutrient N, 200–300 eq ha⁻¹ yr⁻¹, was lower. Site measurements, especially to estimate soil weathering, would increase the certainty of the critical load. We observed significant negative correlations between critical load exceedance and growth (17 species) and crown density (4 species); we observed significant positive correlations of exceedance with declining vigor (four species), with crown dieback (six species) and crown transparency (seven species). Among the species which demonstrate the most significant detrimental responses to atmospheric deposition are balsam fir, red spruce, quaking aspen, and paper birch. These results indicate that significant detrimental responses to atmospheric deposition are being observed across the northeastern USA.

A soil survey was conducted in urban areas from five sites, including Beijing, Baotou, Datong, Fuyang, and Xiantao in China. The objective was to explore the most significant factors that may impact the bioaccessibility of heavy metals (Bio-HMs), including As, Cr, Cu, Pb, and Zn, in soils. Twenty to 30 composite soil samples were collected at each site. The various soil properties, including pH, particle size, Fe/Mn, and organic matter contents, were analyzed. The chemical operated forms of HMs in soils were measured by the Bureau of Reference (BCR) sequential extraction scheme, while the Bio-HMs were determined by the simple bioaccessibility extraction test (SBET) procedure. The concentrations of total heavy metals (T-HMs) in soils from different sites (cities) were in the range as As (5.69–9.86), Cr (77.42–230.20), Cu (15.68–36.54), Pb (14.12–58.93), and Zn (38.66–183.46) mg/kg. Cu and Pb had higher relative bioaccessibilities (48–70 %) than those of As and Cr (6–15 %), indicating higher health risks of the former than the latter two HMs. The Bio-HMs for various HMs were comparable to the first two or three combined BCR extracted fractions, with an exception of Cu, whose Bio-HMs were larger than the combined three BCR fractions, indicating that Cu was highly accessible in soils as compared with other HMs. Factor analysis showed that all variables, including soil property parameters and BCR extracted fractions, could be represented by three common factors extracted with higher than 0.5 loadings and ∼80 % cumulative contribution to the total variance. Among the three common factors, factor 1, containing mainly pH, texture, and Fe/Mn variables, and factor 3, containing mainly organic matter variable, could be attributed to geographical regions, while factor 2, containing mainly BCR extracted fractions, could be ascribed to relative bioaccessibility of HMs (R-Bio-HMs). Interactive mapping of the main factors and cluster analysis were consistent, which supported the “site gathering” of the soil sample pools, suggesting that the Bio-HMs in soils in different geographical localities were site dependent.