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| Titel |
Vegetation composition and soil microbial community structural changes along a wetland hydrological gradient |
| VerfasserIn |
W. K. Balasooriya, K. Denef, J. Peters, N. E. C. Verhoest, P. Boeckx |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 12, no. 1 ; Nr. 12, no. 1 (2008-02-26), S.277-291 |
| Datensatznummer |
250010474
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| Publikation (Nr.) |
 copernicus.org/hess-12-277-2008.pdf |
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| Zusammenfassung |
| Fluctuations in wetland hydrology create an interplay between aerobic and
anaerobic conditions, controlling vegetation composition and microbial
community structure and activity in wetland soils. In this study, we
investigated the vegetation composition and microbial community structural
and functional changes along a wetland hydrological gradient. Two different
vegetation communities were distinguished along the hydrological gradient;
Caricetum gracilis at the wet depression and Arrhenatheretum
elatioris at the drier upper site. Microbial community structural changes
were studied by a combined in situ 13CO2 pulse labeling and
phospholipid fatty acid (PLFA) based stable isotope probing approach, which
identifies the microbial groups actively involved in assimilation of newly
photosynthesized, root-derived C in the rhizosphere soils. Gram negative
bacterial communities were relatively more abundant in the surface soils of
the drier upper site than in the surface soils of the wetter lower site,
while the lower site and the deeper soil layers were relatively more
inhabited by gram positive bacterial communities. Despite their large
abundance, the metabolically active proportion of gram positive bacterial and
actinomycetes communities was much smaller at both sites, compared to that of
the gram negative bacterial and fungal communities. This suggests much slower
assimilation of root-derived C by gram positive and actinomycetes communities
than by gram negative bacteria and fungi at both sites. Ground water depth
showed a significant effect on the relative abundance of several microbial
communities. Relative abundance of gram negative bacteria significantly
decreased with increasing ground water depth while the relative abundance of
gram positive bacteria and actinomycetes at the surface layer increased with
increasing ground water depth. |
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