 |
| Titel |
Effects of stoichiometry and temperature perturbations on beech leaf litter decomposition, enzyme activities and protein expression |
| VerfasserIn |
K. M. Keiblinger, T. Schneider, B. Roschitzki, E. Schmid, L. Eberl, I. Hämmerle, S. Leitner, A. Richter, W. Wanek, K. Riedel, S. Zechmeister-Boltenstern |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 9, no. 11 ; Nr. 9, no. 11 (2012-11-16), S.4537-4551 |
| Datensatznummer |
250007395
|
| Publikation (Nr.) |
 copernicus.org/bg-9-4537-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Microbes are major players in leaf litter decomposition and therefore
advances in the understanding of their control on element cycling are of
paramount importance. Our aim was to investigate the influence of leaf
litter stoichiometry in terms of carbon (C) : nitrogen (N) : phosphorus (P)
ratios on the decomposition processes and to track changes in microbial
community structures and functions in response to temperature stress
treatments. To elucidate how the stoichiometry of beech leaf litter (Fagus sylvatica L.) and stress
treatments interactively affect the microbial decomposition processes, a
terrestrial microcosm experiment was conducted. Beech litter from different
Austrian sites covering C:N ratios from 39 to 61 and C:P ratios from 666 to
1729 were incubated at 15 °C and 60% moisture for six months.
Part of the microcosms were then subjected to severe changes in temperature
(+30 °C and −15 °C) to monitor the influence of
temperature stress. Extracellular enzyme activities were assayed and
respiratory activities measured. A semi-quantitative metaproteomics approach
(1D-SDS PAGE combined with liquid chromatography and tandem mass
spectrometry; unique spectral counting) was employed to investigate the
impact of the applied stress treatments in dependency of litter
stoichiometry on structure and function of the decomposing community. In
litter with narrow C:nutrient (C:N, C:P) ratios, microbial decomposers were
most abundant. Cellulase, chitinase, phosphatase and protease activity
decreased after heat and freezing treatments. Decomposer communities and
specific functions varied with site, i.e. stoichiometry. The applied stress
combined with the respective time of sampling evoked changes of enzyme
activities and litter pH. Freezing treatments resulted in a decline in
residual plant litter material and increased fungal abundance, indicating
slightly accelerated decomposition. Overall, a strong effect of litter
stoichiometry on microbial community structures and functions was detected,
but decomposition was mainly driven by a combination of the investigated
factors. Temperature perturbations resulted in short- to medium-term
alterations of microbial functions; especially high temperature treatments
blocked decomposing enzymes. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|