Effects of plant species on stream bacterial communities via leachate from leaf litter
- 344 Downloads
Leaf litter provides an important resource to forested stream ecosystems. During leaf fall a significant amount of dissolved organic carbon (DOC) enters streams as leaf leachate. We compared the effects of plant species and leaf leachate bioavailability on the composition of stream bacterial communities and rates of DOC decomposition. We used four common riparian tree species that varied in foliar chemistry, leachate optical properties, and litter decomposition rate. We used laboratory microcosms from two streams and amended with a standard concentration of DOC derived from leaf leachate of the four tree species. After 24 h, we measured rates of DOC biodegradation and determined the composition of the bacterial communities via bar-coded pyrosequencing of the 16S rRNA gene. The composition, diversity, and abundance of the bacterial community differed significantly among plant species from both streams. The phylogenetic distance of the different bacterial communities correlated with species-specific leachate optical properties and rates of DOC biodegradation. Highest rates of DOC decomposition were associated with high tannin and lignin leaf types. Results demonstrate that riparian plant species strongly influences stream bacterial communities via their leachate suggesting that alterations to the presence or abundance of riparian plant taxa may influence these communities and associated ecosystem processes.
KeywordsDissolved organic carbon Leaf litter Streams 16S rRNA Fluorescence spectroscopy
This Project benefited from discussions with E. Schwartz. Assistance from B. Moan, J. Potter, and T. Contente is appreciated. Funding came from the National Science Foundation (DEB-1120343 and DEB-1119843). ASW was funded by the National Science Foundation Integrative Graduate Education and Research Traineeship (IGERT) and GK-12 Programs.
- Cole, J. R., Q. Wang, E. Cardenas, J. Fish, B. Chai, R. J. Farris, A. S. Kulam-Syed-Mohideen, D. M. McGarrell, T. Marsh, G. M. Garrity & J. M. Tiedje, 2009. The ribosomal database project: improved alignments and new tools for rRNA analysis. Nucleic Acids Research 37(Supplement 1): D141–D145.CrossRefPubMedGoogle Scholar
- Cory, R. M., M. P. Miller, D. M. McKnight, J. J. Guerard & P. L. Miller, 2010. Effect of instrument-specific response on the analysis of fulvic acid fluorescence spectra. Limnology and Oceanography: Methods 8: 67–78.Google Scholar
- Hooper, D. U., F. S. Chapin III, J. J. Ewel, A. Hector, P. Inchausti, S. Lavorel, J. H. Lawton, D. M. Lodge, M. Loreau, S. Naeem, B. Schmid, H. Setälä, A. J. Symstad, J. Vandermeer & D. A. Wardle, 2005. Effects of biodiversity on ecosystem functioning: a consensus of current knowledge. Ecological Monographs 75: 3–35.CrossRefGoogle Scholar
- Schweitzer, J. A., M. D. Madritch, J. K. Bailey, C. J. LeRoy, D. G. Fisher, B. J. Rehill, A. E. Hagerman, S. C. Wooley, S. C. Hart & T. G. Whitham, 2008. From genes to ecosystems: the genetic basis of condensed tannins and their role in nutrient regulation in Populus model system. Ecosystems 11: 1005–1020.CrossRefGoogle Scholar
- SPSS. IBM Corporation. Released, 2011. IBM SPSS Statistics for Windows, Version 19.0. IBM Corporation, Armonk.Google Scholar
- Weishaar, J. L., G. R. Aiken, B. A. Bergamaschi, M. S. Fram, R. Fujii & K. Mopper, 2003. Evaluation of specific ultraviolet absorbance as an indicator of the chemical composition and reactivity of dissolved organic carbon. Environmental Science and Technology 37: 4702–4708.CrossRefPubMedGoogle Scholar