Rapid deglaciation is one of the most important challenges in the Earth science today.One reason of this is specific supraglacial sediments–cryoconites,which represent carbon-containing dust with organomineral matter...Rapid deglaciation is one of the most important challenges in the Earth science today.One reason of this is specific supraglacial sediments–cryoconites,which represent carbon-containing dust with organomineral matter and living organisms.Investigation of physical and chemical characteristics of cryoconites in the Central Caucasus is necessary in order to understand their influence on alpine territories biogeochemical cycles,pollution and development in conditions of intensive glacial melting and active anthropogenic influence.For this research cryoconites as well as moraines,soil-like bodies and soils have been sampled from the alpine Bezengi Glacier and adjacent Khulamo-Bezengi Gorge.Key physicochemical features(pH values,total organic carbon content,microbial respiration,particle-size distribution)as well as content of trace elements have been defined in sampled materials and several pollution indices(Geoaccumulation index,Contamination factor and Degree of pollution)have been calculated.Results obtained show low values of total organic carbon in cryoconites(max.0.23%)but high values(max.7.54%)in top horizon of soils located in floodplain,indicating its active fluvioglacial transfer which may further accelerate the development of soils.Microbiological activity in the studied soils was mostly influenced by additional input of labile organic carbon from cryoconites with water flows.Particle-size distribution was similar among the studied cryoconites,indicating dominance of sand fraction(up to 85.28%)while studied soils showed higher variability due to influence of weathering.Among the trace elements,cryoconites were mostly polluted by Zn(max.85.70 mg·kg^(-1))which corresponds to high pollution according to pollution indices;Pb(max.24.90 mg·kg^(-1))and Cu(max.17.40 mg·kg^(-1)),up to moderate pollution level.Redistribution of polluted cryoconite material as well as local anthropogenic activities increased pollution of periglacial soils by Zn(max.89.20 mg·kg^(-1)),Pb(max.15.00 mg·kg^(-1))and Cu(max.12.80 mg·展开更多
Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of...Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties.Results: The results were analysed using analysis of variance. During the first 25 years after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+and available P in the topsoil(0–10 cm and 11–20 cm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+concentration decreased and exchangeable Fe3+and Al3+concentration increased.Conclusions: The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern.展开更多
基金supported by the Russian Foundation for Basic Research,project No 19-05-50107。
文摘Rapid deglaciation is one of the most important challenges in the Earth science today.One reason of this is specific supraglacial sediments–cryoconites,which represent carbon-containing dust with organomineral matter and living organisms.Investigation of physical and chemical characteristics of cryoconites in the Central Caucasus is necessary in order to understand their influence on alpine territories biogeochemical cycles,pollution and development in conditions of intensive glacial melting and active anthropogenic influence.For this research cryoconites as well as moraines,soil-like bodies and soils have been sampled from the alpine Bezengi Glacier and adjacent Khulamo-Bezengi Gorge.Key physicochemical features(pH values,total organic carbon content,microbial respiration,particle-size distribution)as well as content of trace elements have been defined in sampled materials and several pollution indices(Geoaccumulation index,Contamination factor and Degree of pollution)have been calculated.Results obtained show low values of total organic carbon in cryoconites(max.0.23%)but high values(max.7.54%)in top horizon of soils located in floodplain,indicating its active fluvioglacial transfer which may further accelerate the development of soils.Microbiological activity in the studied soils was mostly influenced by additional input of labile organic carbon from cryoconites with water flows.Particle-size distribution was similar among the studied cryoconites,indicating dominance of sand fraction(up to 85.28%)while studied soils showed higher variability due to influence of weathering.Among the trace elements,cryoconites were mostly polluted by Zn(max.85.70 mg·kg^(-1))which corresponds to high pollution according to pollution indices;Pb(max.24.90 mg·kg^(-1))and Cu(max.17.40 mg·kg^(-1)),up to moderate pollution level.Redistribution of polluted cryoconite material as well as local anthropogenic activities increased pollution of periglacial soils by Zn(max.89.20 mg·kg^(-1)),Pb(max.15.00 mg·kg^(-1))and Cu(max.12.80 mg·
基金supported by University of Latvia grant Nr. AAp2016/B041//Zd2016/AZ03 within the project “Climate change and sustainable use of natural resources”。
文摘Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties.Results: The results were analysed using analysis of variance. During the first 25 years after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+and available P in the topsoil(0–10 cm and 11–20 cm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+concentration decreased and exchangeable Fe3+and Al3+concentration increased.Conclusions: The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern.
