Open AccessIn situ carbon turnover dynamics and the role of soil microorganisms therein: a climate warming study in an A lpine ecosystem
Author(s) -
Djukic Ika,
Zehetner Franz,
Watzinger Andrea,
Horacek Micha,
Gerzabek Martin H.
Publication year - 2013
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2012.01449.x
Subject(s) - ecosystem , carbon cycle , microbial population biology , litter , biogeochemical cycle , ecology , substrate (aquarium) , soil water , soil carbon , environmental science , plant litter , terrestrial ecosystem , dissolved organic carbon , carbon fibers , decomposition , biology , climate change , environmental chemistry , chemistry , genetics , bacteria , materials science , composite number , composite material
Litter decomposition represents one of the largest fluxes in the global terrestrial carbon cycle. The aim of this study was to improve our understanding of the factors governing decomposition in alpine ecosystems and how their responses to changing environmental conditions change over time. Our study area stretches over an elevation gradient of 1000 m on the H ochschwab massif in the N orthern L imestone A lps of A ustria . We used high‐to‐low elevation soil translocation to simulate the combined effects of changing climatic conditions, shifting vegetation zones, and altered snow cover regimes. In original and translocated soils, we conducted in situ decomposition experiments with maize litter and studied carbon turnover dynamics as well as temporal response patterns of the pathways of carbon during microbial decomposition over a 2‐year incubation period. A simulated mean annual soil warming (through down‐slope translocation) of 1.5 and 2.7 °C, respectively, resulted in a significantly accelerated turnover of added maize carbon. Changes in substrate quantity and quality in the course of the decomposition appeared to have less influence on the microbial community composition and its substrate utilization than the prevailing environmental/site conditions, to which the microbial community adapted quickly upon change. In general, microbial community composition and function significantly affected substrate decomposition rates only in the later stage of decomposition when the differentiation in substrate use among the microbial groups became more evident. Our study demonstrated that rising temperatures in alpine ecosystems may accelerate decomposition of litter carbon and also lead to a rapid adaptation of the microbial communities to the new environmental conditions.