Ecohydrologically important subsurface structures in peatlands revealed by ground-penetrating radar and complex conductivity surveys.

The surface pattern of vegetation influences the composition and humification of peat laid down during the development of a bog, producing a subsurface hydrological structure that is expected to affect both the rate and pattern of water flow. Subsurface peat structures are routinely derived from the inspection of peat cores. However, logistical limits on the number of cores that can be collected means that the horizontal extent of these structures must be inferred. We consider whether subsurface patterns in peat physical properties can be mapped in detail over large areas with ground-penetrating radar (GPR) and complex conductivity by comparing geophysical measurements with peat core data along a 36 m transect through different microhabitats at Caribou Bog, Maine. The geophysical methods show promise. Peat horizons produced radar reflections because of changes in the volumetric moisture content. Although these reflections could not be directly correlated with the peat core data, they were related to the depth-averaged peat properties which varied markedly between the microhabitats. Well-decomposed peat below a hollow was characterized by a discontinuous sequence of chaotic wavy reflections, while distinct layering of the peat below an area of hummocks coincided with a pattern of parallel planar reflections. The complex conductivity survey showed spatial variation in the real and imaginary conductivities which resulted from changes in the pore water conductivity; peat structures may also have influenced the spatial pattern in the complex conductivity. The GPR and complex conductivity surveys enabled the developmental history of the different microhabitats along the studied transect to be inferred

Biomonitoring of atmospheric trace elements in agricultural areas and a former uranium mine

Most biomonitoring studies worldwide have evaluated the air quality in industrial and urban areas, and even in mining areas to a lesser extent. However, air quality investigations in agricultural areas are scarce. In the present study, the trace metal accumulation and physiological response of the biomonitor Tillandsia capillaris were assessed. Plant samples were transplanted to a reference site, a former open-cast uranium mine, and agricultural sites with varying pollution levels (from normal agricultural practices and near an open rubbish dump) in the province of Córdoba, Argentina. Biomonitors were exposed to ambient air for different exposure periods for physiological or trace element determination. The bioindicators revealed that the highest physiological damage occurred at the sites close to the open dump and the former uranium mine, while a comparison among exposure periods indicating the winter season produced the highest physiological damage in the biomonitor due to the adverse climatic conditions and air pollution. As the trace metal accumulation in the biomonitor was mainly associated with the open dump and uranium mine sites, monitoring and remediation programs should now be applied to these sites in order to alleviate the negative effects of pollution on the environment and the population.Fil: Rodriguez, Judith Hebelen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Wannaz, Eduardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Weller, Sebastian Benjamin. Karlsruher Institut Fur Technologie; AlemaniaFil: Pignata, María Luisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentin

Constraining recent lead pollution sources in the North Pacific using ice core stable lead isotopes

Trends and sources of lead (Pb) aerosol pollution in the North Pacific rim of North America from 1850 to 2001 are investigated using a high-resolution (subannual to annual) ice core record recovered from Eclipse Icefield (3017 masl; St. Elias Mountains, Canada). Beginning in the early 1940s, increasing Pb concentration at Eclipse Icefield occurs coevally with anthropogenic Pb deposition in central Greenland, suggesting that North American Pb pollution may have been in part or wholly responsible in both regions. Isotopic ratios (208Pb/207Pb and 206Pb/207Pb) from 1970 to 2001 confirm that a portion of the Pb deposited at Eclipse Icefield is anthropogenic, and that it represents a variable mixture of East Asian (Chinese and Japanese) emissions transported eastward across the Pacific Ocean and a North American component resulting from transient meridional atmospheric flow. Based on comparison with source material Pb isotope ratios, Chinese and North American coal combustion have likely been the primary sources of Eclipse Icefield Pb over the 1970–2001 time period. The Eclipse Icefield Pb isotope composition also implies that the North Pacific mid-troposphere is not directly impacted by transpolar atmospheric flow from Europe. Annually averaged Pb concentrations in the Eclipse Icefield ice core record show no long-term trend during 1970–2001; however, increasing 208Pb/207Pb and decreasing 206Pb/207Pb ratios reflect the progressive East Asian industrialization and increase in Asian pollutant outflow. The post-1970 decrease in North American Pb emissions is likely necessary to explain the Eclipse Icefield Pb concentration time series. When compared with low (lichen) and high (Mt. Logan ice core) elevation Pb data, the Eclipse ice core record suggests a gradual increase in pollutant deposition and stronger trans-Pacific Asian contribution with rising elevation in the mountains of the North Pacific rim

Soils of Seabee Hook, Cape Hallett, northern Victoria Land, Antarctica

The soils of the Seabee Hook area of Cape Hallett in northern Victoria Land, Antarctica, were mapped and characterized. Seabee Hook is a low-lying gravel spit of beach deposits built up by coastal currents carrying basalt material from nearby cliffs. Seabee Hook is the location of an Adélie penguin (Pygoscelis adeliae) colony which influences the soils with additions of guano, dead birds, eggshells and feathers. A soil-landscape model was developed and a soil association was identified between the soils formed on mounds (relict beach ridges) favoured by penguins for nests (Typic Haplorthel) and the soils in the areas between the mounds (Typic Haplorthel/Typic Aquorthel). Soils formed on the mounds inhabited by penguins contained guano in the upper 50 cm, overlying sub-rounded beach-deposited gravel and sand. Soils between mounds had a thin veneer (< 5 cm) of guano overlying basaltic gravelly sand similar to that in the lower parts of the mound soils. The soils had high concentrations of nitrogen, organic carbon, phosphorus, cadmium, zinc, copper, and increased electrical conductivity, within horizons influenced by penguin guano. Five buried penguin bones were collected from the base of soil profiles and radiocarbon dated. The dates indicate that Seabee Hook has been colonized by penguins for at least 1000 years

Towards understanding the effect of heavy metals on mycobiont physiological condition in a widespread metal-tolerant lichen Cladonia rei

Heavy metals present in the environment can cause a variety of injury symptoms in various organisms including lichens. Most studies examined metal-induced stress under controlled laboratory conditions, and little is known about actual response of lichens in their natural habitat. This study aims to recognize the effect of heavy metal accumulation (total and intracellular) on lichen physiological and biochemical parameters specifically related to the functioning of fungal component. Cladonia rei was used as a model species due to its common occurrence both in unpolluted and extremely polluted sites. We observed a decline in the fungal metabolism which was expressed by a decrease in ergosterol content and an increase in cell membrane damage as a result of increased Zn, Cd, Cu and Ni accumulation. Additionally, the results indicated that increased accumulation of xenobiotics (Pb and As) caused reduction of glutathione (GSH) concentrations and increased membrane lipid peroxidation. Therefore, we conclude that GSH does not provide high oxidative stress protection in C. rei which is somewhat against its insensitivity to pollution. The reduced pool of GSH could be explained by its oxidation to glutathione disulphide induced by heavy metal stress or its use for phytochelatin (PC) synthesis. The content of secondary metabolites was not related to heavy metal accumulation and remained at a relatively stable level. This indicates that the decline in the physi-ological condition did not weaken the mycobiont of C. rei enough to inhibit the synthesis of secondary metabolites and their precursors were supplied at a sufficient level. Thus, the potential function of main secondary metabolites as extracellular metal immobilizers and antioxidants is still possible even in individuals growing at extremely polluted sites. Despite the evident heavy metal stress, C. rei copes well and spreads easily through extremely polluted environments, which underlines its unique pioneering abilities in highly disturbed sites

Heavy metals air pollution study in mines environments. Case study Bregalnica river basin, Republic of Macedonia

Application of several moss species and attic dust for monitoring of anthropogenic impact on heavy metals air pollution in Bregalnica River Basin, Republic of Macedonia, was studied. Moss samples were reviewed for their potential to reflect heavy metals air pollution. The attention was focused on their quantification ability, underlying the metal accumulation within moss plant tissue and attic dust “historical archiving”. Potential “hot spots” were selected in areas of copper mine (Bučim mine) and lead and zinc mines (Zletovo mine and Sasa mine) as main metal pollution sources in the Eastern part of the Republic of Macedonia. Continuously, dust distribution from ore and flotation tailings occurs. This results with air-introduction and deposition of higher contents of certain metals. Several moss species (Hypnum cupressiforme, Homalothecium lutescens and Scleropodium purum) were used as plant sampling media. Determination of chemical elements was conducted by using both instrumental techniques: atomic emission spectrometry with inductively coupled plasma (ICP-AES) and mass spectrometry with inductively coupled plasma (ICP-MS). Combination of multivariate techniques (PCA, FA and CA) was applied for data processing and identification of elements association with lithogenic or anthropogenic origin. Spatial distribution maps were constructed for determination and localizing of narrower areas with higher contents of certain anthropogenic elements. In this way influences of selected human activities in local (small scale) air pollution can be determined. Summarized data reveal real quantification of the elements distribution not only in order determination of hazardously elements distribution, but also present complete characterization for elements deposition in mines environs