Microbial Communities and Soil Structure are Affected by Reduced Precipitation, but Not by Elevated Carbon Dioxide
Elevated carbon dioxide (eCO2) concentrations in the atmosphere, along with decreased precipitation regimes expected in the next decades, can alter soil microbe functioning and hence soil organic matter (SOM) dynamics causing important impacts on the global C cycle. We investigated the effects of eC...
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Published in | Soil Science Society of America journal Vol. 77; no. 2; pp. 482 - 488 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Madison
The Soil Science Society of America, Inc
01.03.2013
American Society of Agronomy |
Subjects | |
Online Access | Get full text |
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Summary: | Elevated carbon dioxide (eCO2) concentrations in the atmosphere, along with decreased precipitation regimes expected in the next decades, can alter soil microbe functioning and hence soil organic matter (SOM) dynamics causing important impacts on the global C cycle. We investigated the effects of eCO2 and reduced soil moisture, further referred to as reduced precipitation treatment (RP), on SOM fractions and soil microbial distribution across different soil zones (i.e., rhizosphere vs. bulk soil) and physically‐separated SOM fractions (coarse particulate organic matter (cPOM; >250 mm), microaggregate (53–250 mm), and silt‐and‐clay fraction (<53 mm)) at the soybean free air concentration enrichment (SoyFACE) experiment in Illinois. To quantify the abundance of microorganisms, we used real‐time quantitative polymerase chain reaction (PCR) for the total bacterial (16S rRNA) and denitrifier (nosZ) genes. We did not detect any significant effects of eCO2 on bacterial abundance, soil C, and N concentrations either in the whole soil or in the SOM fractions. These findings corroborate the previously reported absence of soil C responses to eCO2. The mass of microaggregates was highest in RP treatments in both rhizosphere and bulk soil. Furthermore, the abundance of 16S rRNA and nosZ genes increased in the microaggregates under RP compared to ambient conditions of soil moisture. Hence, RP increased the formation of microhabitats in which the microorganisms are partly protected from the adverse effects of reduced soil moisture. |
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Bibliography: | All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0361-5995 1435-0661 |
DOI: | 10.2136/sssaj2012.0218 |