| Studies | Unique Samples per Visibility Status | Public Samples per Data Type | Users | Jobs |
|---|---|---|---|---|
|
public: 884 private: 176 sandbox: 2,971 submitted to EBI: 1,146 |
public: 437,560 private: 118,594 sandbox: 658,943 submitted to EBI: 390,075 submitted to EBI (prep): 453,406 |
16S: 388,764 18S: 12,149 ITS: 15,550 Metagenomic: 106,100 Full Length Operon: 803 Metatranscriptomic: 27,161 Metabolomic: 1,545 Genome Isolate: 1,505 |
17,115 | 934,500 |
Soil microorganisms are key drivers of terrestrial biogeochemical cycles, yet it is still unclear how variations in soil microbial community composition influence many ecosystem processes. We investigated how shifts in bacterial community composition and diversity resulting from differences in carbon (C) availability affect organic matter decomposition by conducting an in situ litter manipulation experiment in a tropical rain forest in Costa Rica. We used bar-coded pyrosequencing to characterize soil bacterial community composition in litter manipulation plots and performed a series of laboratory incubations to test the potential functional significance of community shifts on organic matter decomposition. Despite clear effects of the litter manipulation on soil bacterial community composition, the treatments had mixed effects on microbial community function. Distinct communities varied in their ability to decompose a wide range of C compounds, and functional differences were related to both the relative abundance of the two most abundant bacterial sub-phyla (Acidobacteria and Alphaproteobacteria) and to variations in bacterial alpha-diversity. However, distinct communities did not differ in their ability to decompose native dissolved organic matter (DOM) substrates that varied in quality or quantity. Our results show that while resource-driven shifts in soil bacterial community composition have the potential to influence decomposition of specific C substrates, those differences may not translate to differences in DOM decomposition rates in situ. Taken together, our results suggest that soil bacterial communities may be either functionally dissimilar or equivalent during decomposition depending on the nature of the organic matter being decomposed.