Characterization of organic-rich mineral debris revealed by rapid glacier retreat, Indren Glacier, European Alps  

作　　者：FREPPAZ Michele WILLIAMS Mark W. GABRIELI Jacopo GORRA Roberta MANIA Ilaria ASCHER-JENULL Judith EGLI Markus CELI Luisella 

机构地区：[1]Department of Agriculture,Forest and Food Sciences,University of Turin,Largo Paolo Braccini 2,10095 Grugliasco(TO),Italy [2]NatRisk Research Centre on Natural Risks in Mountain and Hilly Environments,University of Turin,Largo Paolo Braccini 2,10095 Grugliasco(TO),Italy [3]Institute of Arctic and Alpine Research and Department of Geography,University of Colorado at Boulder,UCB 450,Boulder,CO 80309,USA [4]CNR-ISP(Consiglio Nazionale delle Ricerche,Istituto di Scienze Polari),via Torino 155,30172 Venezia-Mestre,Italy [5]Institute of Microbiology,University of Innsbruck,Technikerstraße 25,6020 Innsbruck,Austria [6]Department of Geography,University of Zurich,Winterthurerstrasse 190,8057 Zurich,Switzerland

出　　处：《Journal of Mountain Science》2021年第6期1521-1536,共16页山地科学学报（英文）

基　　金：Manuscript writing was supported by the Italian MIUR Project(PRIN 2010–11):“Response of morphoclimatic system dynamics to global changes and related geomorphological hazards”(national coordinator C.Baroni);the contribution of MW Williams was supported by the US NSF-funded Niwot Ridge Long-Term Ecological Research program。

摘　　要：In the summer of 2003 and 2004, characterized by a rapid glacier retreat, a stony surface covered by well-structured organic-rich mineral debris was observed very close to the Indren glacier terminus(Monte Rosa Massif, NW Italy, 3100 m ASL), on an area covered by the glacier tongue till the year before. The origin and type of this organicrich material were investigated, in order to detect their characteristics, potential sources and fate within the foreland system. The deposits were dated using Carbon-14 and analyzed for the chemical characteristics of the organic component, the elemental composition of the mineral fraction and presence of microbial markers. The material, granular and dark in color, had a total organic carbon(TOC) content ranging between 17.4 ± 0.39 and 28.1 ± 0.63 g kg^(-1) dry weight(dw), significantly higher than the surrounding glacial till(~ 1.4 g kg^(-1) dw), although only 0.33% of it was in water soluble form. Microbial carbon(C) and nitrogen(N) accounted for 10.6% and 3.13% of TOC and total N, respectively. Dissolved nitrogen(N), mainly present as ammonium, represented 2.40% of the total N. The low aromatic component and large presence of nitrogen(N)-derived compounds suggested that most of the organic carbon(OC) in these organic-rich mineral deposits was derived from microbial cells, although the high average radiocarbon age of about 2900 years may also point to the contribution of aeolian depositions of anthropogenic or natural origin. Elemental composition and the crustal enrichment factor of trace elements in the mineral fraction of the aggregates corroborated the hypothesis that most part of the accumulated material derived from ice meltwater. Some indicators of the colonization of these deposits by microbial communities were also reported, from the abundance of DNA and phylogenetic markers, to the presence of bacterial taxa commonly able to thrive in similar habitats. All these elements suggested that such kind of deposits may have a potential role as energy and nutrient sources i

关 键 词：Glacier foreland Dissolved organic carbon Organic matter q PCR Microbial community Trace elements 

分 类 号：P343.6[天文地球—水文科学]