Overview

Microorganisms are the Earth`s firstborn. They were teeming on the land and in the seas for billions of years before the evolution of plants and animals, and their diversity is staggering. Every pinch of soil contains billions of microbes whose activities regulate terrestrial nutrient cycles and influence the evolution of our biosphere. Despite their importance many aspects of soil microbial communities are still a mystery and soil remains a fertile habitat for discovery. My research makes use of genomic tools to examine the microbial communities that live in soils, to explore their diversity, and to delineate the mechanisms by which they influence environmental processes in terrestrial ecosystems.

Research Focus

In the broadest terms my research program focuses on issues that relate to soil microbial diversity: its extent, its regulation, and its impact on biogeochemical cycles that regulate soil fertility and influence atmospheric chemistry. My lab is currently using nitrogen fixation as a model system for exploring the role of microbial diversity on ecosystem function. Free-living diazotrophs in soils provide the dominant natural source of fixed N in many terrestrial systems, and yet we know remarkably little about the ecology and evolution of these microorganisms. We are using a novel approach that combines Stable Isotope Probing (SIP) with environmental genomics to examine genomic information from non-cultivated diazotrophs. This research will significantly advance our understanding of the environmental mechanisms that regulate the diversity and activity of free-living N-fixing microorganisms in soils and will provide insights on the ecology and evolution of a microbial process that is of central importance to the global N cycle.

Outreach and Extension Focus

In collaboration with the Cornell Institute for Biology Teachers and other faculty at Cornell I organize and teach a summer workshop for high school science teachers. The workshop, "The Microbial Earth ", is a week long laboratory based experience that focuses on the role of microorganisms in the natural world. The workshop is designed to provide teachers with practical tools and open ended laboratory exercises from the microbial world that they can use to get their students excited about science.

Instruction Focus

CSS410: The GMO Debate: Environmental Impacts This course covers issues pertaining to the agricultural use of transgenic organisms with emphasis on evaluating their potential environmental impacts. Students learn to critically evaluate the ecological risks and benefits associated with agricultural practices and the impact of transgenic organisms in agroecosystems. CSS674: Environmental Genomics Genomics opens new avenues for exploring interactions between organisms and their environment. This course focuses on the use of genomic tools to provide insight on processes occurring at individual, population, and ecosystem scales which govern the response of biological systems to environmental change. CSS684: Topics in Soil Microbial Ecology This seminar course reviews current and groundbreaking literature in soil microbial ecology with topics that encompass: microbial biogeography and diversity, biogeochemistry, microbial feedbacks on plant communities, gene exchange and evolution in soils, soil microbial genomics, bioremediation, and relationships between community structure & ecological function in soils.

Additional Links

• Buckley Lab
• New Life Sciences Initiative
• Link to CALS Research portal
• Link to CALS Impact statements

Honors, Awards and Appointments

• NSF Early Faculty CAREER Award - 2005-2010
• NSF Postdoctoral Fellowship in Microbial Biology - 2001-2003
• Phi Beta Kappa, Iota Chapter, University of Rochester - 1994

Professional Activities

• Member of NSF Antarctic Organisms and Ecosystems Grant Panel - September 17-19, 2007
• Member of NASA Exobiology Grant Panel - June 12-15, 2007
• Presented seminar on "Stable isotope probing with 15N2 as a tool to uncover the functional significance of non-cultivated diazotrophs in soil " Presented at the World Congress of Soil Science, Philadelphia, PA - July 12, 2006
• Presented seminar on "Microbial Diversity: The Final Frontier " at the Jepson Herbarium, University of California, Berkeley, CA - January 20, 2007
• Chair of working group at American Academy of Microbiology Critical Issues Colloquium on, "The Uncharted Microbial World: Microbes and Their Activities in the Environment ", Seattle, WA - February 9-11, 2007

Selected Publications

• Buckley, D. H. and T. M. Schmidt (2001) Environmental factors influencing the distribution of Verrucomicrobia in soil. FEMS Microbial Ecology. 35:105-112.
• Buckley, D. H. and T. M. Schmidt (2001) The structure of microbial communities in soil and the lasting impact of cultivation. Microbial Ecology. 42:11-21.
• Buckley, D. H., J. R. Graber, T. M. Schmidt (1998) Phylogenetic analysis of nonthermophilic members of the Kingdom Crenarchaeota and their diversity and abundance in soils. Applied and Environmental Microbiology. 64:3781-3787.
• S. Hsu, T. A. Nelson, D. H. Buckley (2007) "Linking the diversity and activity of diazotrophs across a gradient of agricultural disturbance " Published in the Proceedings of the 107th General Meeting of the American Society of Microbiology.
• Buckley, D. H. and T. M. Schmidt (2007) Measurement of ribosomal RNA abundance by hybridization with oligonucleotide probes. In Methods for General and Molecular Microbiology. Reddy, C. A., T. J. Beveridge, J. A. Breznak, G. A. Marzluf and T. M. Schmidt (eds.). American Society for Microbiology, Washington, D.C.
• Buckley, D. H., S. Hsu, V. Haungyutitham, T. Nelson (2007) "Analysis of 16S rRNA and nifH genes through 15N2 stable isotope probing reveal that novel Actinobacteria mediate nitrogen fixation in soil " Published in the Proceedings of the 107th General Meeting of the American Society of Microbiology.
• Buckley, D. H., V. Huangyutitham, S-F. Hsu, and T. A. Nelson. (2007) Stable isotope probing with 15N achieved by disentangling the effects of genome G + C content and isotope enrichment on DNA density. Applied and Environmental Microbiology. 73:3189-3195
• Buckley, D. H. V. Huangyutitham, S-F. Hsu, T. A. Nelson (2007) 15N-Stable isotope probing of DNA as a tool for characterizing the functional significance of free-living diazotrophs in soil. Soil Biology and Biochemistry. In Press.
• Buckley, D. H., V. Huangyutitham, S-F. Hsu, and T. A. Nelson. (2007) Stable isotope probing with 15N achieved by disentangling the effects of genome G + C content and isotope enrichment on DNA density. Applied and Environmental Microbiology. 73:3189-3195
• Buckley, D. H., V. Huangyutitham, S-F. Hsu, and T. A. Nelson. (2007) Stable isotope probing with 15N2 reveals novel non-cultivated diazotrophs in soil. Applied and Environmental Microbiology. 73:3196-3204
• Buckley, D. H., V. Huangyutitham, T. A. Nelson, A. Rumberger, and J. E. Thies (2006) Diversity of Planctomycetes in soil in relation to soil history and environmental heterogeneity. Applied and Environmental Microbiology. 72:4522-4531.
• Buckley, D. H. and T. M. Schmidt (2003) The structure of microbial communities in soil: patterns of microbial distribution their dynamic nature and the lasting impact of cultivation. Environmental Microbiology. 5:441-452.

[top]