Resolving Conflicting Physical and Biochemical Feedbacks to Climate in Response to Long-Term Warming
The goal of the research was to increase our understanding of the microbial mechanisms that control soil organic matter decay in the context of a changing climate. We hypothesized that a major source of carbon respired after long-term soil warming is recalcitrant soil C mineralized by microbes. We found that long-term warming was associated with decreased fungal communities but not bacterial communities, with bacterial communities in organic horizon soils significantly affected by warming. Molecular analysis indicated that this community shift was towards a more oligotrophic community, consistent with previously observed decreased in soil organic matter quality and quantity. We further hypothesized that low labile C resulting from long-term warming has selected for a microbial community that is better able to mineralize recalcitrant C. Analysis of soil communities and individual isolates physiology showed that long-term warming caused bacteria to have increased potential lignolytic activitiy as well as increased carbohydrate degradation potential. This increased ability to degrade recalcitrant soil organic matter is suggested as a mechanism for accelerated soil carbon loss with long-term warming. Soil warming was shown to have little change in transcriptional activity or proteins levels of the enzymes related to recalcitrant C, and little change in the temperature sensitivity of enzyme activity.
- Research Organization:
- Univ. of Massachusetts, Amherst, MA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division
- DOE Contract Number:
- SC0016571
- OSTI ID:
- 1828900
- Report Number(s):
- DOE_UMA_SC0016571
- Resource Relation:
- Related Information: a list of publications fully or partly attributed to the granto DeAngelis, Kristen M*, Grace Pold, Begüm Topçuoğlu, Linda T A van Diepen, Jeffrey L. Blanchard, Jerry Melillo, Serita D Frey (2015) “Long-term forest soil warming alters microbial communities in temperate forest soils.” Frontiers in Microbiology, 6:104. DOI: 10.3389/fmicb.2015.00104o Pold, Grace, Jerry Melillo, Kristen M DeAngelis* (2015) “Two decades of warming increases diversity of a potentially lignolytic bacterial community.” Frontiers in Microbiology 6:480. DOI: 10.3389/fmicb.2015.00480o Pold, Grace, Andrew F Billings, Jeffrey L. Blanchard, Daniel B Burkhardt UG, Serita D Frey, Jerry M Melillo, Julia SchnabelUG, Linda T A van Diepen, Kristen M DeAngelis* (2016) “Long-term warming alters carbohydrate degradation potential in temperate forest soils.” Applied and Environmental Microbiology, 82: 6518-6530. DOI: 10.1128/AEM.02012-16o Pold, Grace, Kristen M DeAngelis* (2013) “Up against the wall: the effects of climate warming on soil microbial diversity and the potential for feedbacks to the carbon cycle.” Diversity v5(2), 409-425. DOI: 10.3390/d5020409o Priyanka Roy Chowdhury, Andrew F. Billings, Lauren V. Altieo, Jeffrey L. Blanchard, Jerry M. Melillo, Kristen M. DeAngelis (in prep) “The transcriptional response of bacteria to long-term warming and short-term seasonal fluctuations in a terrestrial forest.”
- Country of Publication:
- United States
- Language:
- English
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