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Interaction between lithification and resource availability in the microbialites of Río Mesquites, Cuatro Ciénegas, México
Author(s) -
Corman J. R.,
PoretPeterson A. T.,
Uchitel A.,
Elser J. J.
Publication year - 2016
Publication title -
geobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.859
H-Index - 72
eISSN - 1472-4669
pISSN - 1472-4677
DOI - 10.1111/gbi.12168
Subject(s) - lithification , resource (disambiguation) , business , geochemistry , geology , diagenesis , computer science , computer network
Abstract Lithified microbial structures (microbialites) have been present on Earth for billions of years. Lithification may impose unique constraints on microbes. For instance, when Ca CO 3 forms, phosphate may be captured via coprecipitation and/or adsorption and potentially rendered unavailable for biological uptake. Therefore, the growth of microbes associated with Ca CO 3 may be phosphorus‐limited. In this study, we compared the effects of resource addition on biogeochemical functions of microbial communities associated with microbialites and photoautotrophic microbial communities not associated with Ca CO 3 deposition in Río Mesquites, Cuatro Ciénegas, México. We also manipulated rates of Ca CO 3 deposition in microbialites to determine whether lithification reduces the bioavailability of phosphorus (P). We found that P additions significantly increased rates of gross primary production ( F 2,13 = 103.9, P < 0.001), net primary production ( F 2,13 = 129.6, P < 0.0001) and ecosystem respiration ( F 2,13 = 6.44, P < 0.05) in the microbialites, while P addition had no effect on photoautotrophic production in the non‐Ca CO 3 ‐associated microbial communities. Growth of the non‐Ca CO 3 ‐associated phototrophs was only marginally stimulated when nitrogen and P were added simultaneously ( F 1,36 = 3.98, P = 0.053). In the microbialites, resource additions led to some shifts in the abundance of Proteobacteria, Bacteroidetes and Cyanobacteria but mostly had little effect on bacterial community composition. Ca 2+ uptake rates increased significantly with organic carbon additions ( F 1,13 = 8.02, P < 0.05). Lowering of Ca CO 3 deposition by decreasing calcium concentrations in the water led to increased microbial biomass accumulation rates in terms of both organic carbon ( F 4,48 = 5.23, P < 0.01) and P ( F 6,48 = 13.91, P < 0.001). These results provide strong evidence in support of a role of lithification in controlling P limitation of microbialite communities.