9 research outputs found
Ecological engineering and biological polishing for drainage from the Faro waste rock dumps
Report examines the potential of ecological engineering to reduce contamination at the Faro site
Chemical and isotopic switching within the subglacial environment of a high Arctic glacier.
Natural environmental isotopes of nitrate, sulphate and inorganic carbon are discussed in conjunction with major ion chemistry of subglacial runoff from a High Arctic glacier, Midre Lovénbreen, Svalbard. The chemical composition of meltwaters is observed to switch in accordance with subglacial hydrological evolution and redox status. Changing rapidly from reducing to oxidizing conditions, subglacial waters also depict that 15N/14N values show microbial denitrification is an active component of nutrient cycling beneath the glacier. 18O/16O ratios of sulphate are used to elucidate mechanisms of biological and abiological sulphide oxidation. Concentrations of bicarbonate appear to be governed largely by the degree of rock:water contact encountered in the subglacial system, rather than the switch in redox status, although the potential for microbiological activity to influence ambient bicarbonate concentrations is recognised. Glaciers are therefore highlighted as cryospheric ecosystems supporting microbial life which directly impacts upon the release of solute through biogeochemically mediated processes
Intraâ and interâcores fungal diversity suggests interconnection of different habitats in an Antarctic frozen lake (Boulder Clay, Northern Victoria Land)
A perennially frozen lake at Boulder Clay site (Victoria Land, Antarctica), characterized by the presence of frost mounds, have been selected as an in situ model for ecological studies. Different samples of permafrost, glacier ice and brines have been studied as a unique habitat system. An additional sample of brines (collected in another frozen lake close to the previous one) was also considered. Alpha- and beta-diversity of fungal communities showed both intra- and inter-cores significant (p <â0.05) differences, which suggest the presence of interconnection among the habitats. Therefore, the layers of frost mound and the deep glacier could be interconnected while the brines could probably be considered as an open habitat system not interconnected with each other. Moreover, the absence of similarity between the lake ice and the underlying permafrost suggested that the lake is perennially frozen based. The predominance of positive significant (p <â0.05) co-occurrences among some fungal taxa allowed to postulate the existence of an ecological equilibrium in the habitats systems. The positive significant (p <â0.05) correlation between salt concentration, total organic carbon and pH, and some fungal taxa suggests that a few abiotic parameters could drive fungal diversity inside these ecological niches.n
High-resolution electrical resistivity tomography applied to patterned ground, Wedel Jarlsberg Land, south-west Spitsbergen
This article presents results of two-dimensional electrical resistivity tomography (ERT) applied to three types of patterned ground in Wedel-Jarlsberg Land (Svalbard), carried out in late July 2012. The structures investigated include sorted circles, non-sorted polygons and a net with sorted coarser material. ERT was used to recognize the internal ground structure, the shape of permafrost table below the active layer and the geometric relationships between permafrost, ground layering and surface patterns. Results of inversion modelling indicate that the permafrost table occurs at a depth of 0.5â1 m in a mountain valley and 1â2.5 m on raised marine terraces. The permafrost table was nearly planar beneath non-sorted deposits and wavy beneath sorted materials. The mutual relationships between the permafrost table and the shape of a stone circle are different from those typically presented in literature. Ground structure beneath the net with sorted coarser materials is complex as implied in convective models. In non-sorted polygons, the imaging failed to reveal vertical structures between them