Stephanie Yarwood

            I have researched several different aspects of microbial community structure and function.  Part of my work has examined the diversity of fungi, bacteria, and archaea in forest soils here in the Pacific Northwest.  I have also focused on functional groups such as ammonia-oxidizing bacteria and archaea and on denitrifying bacteria.  Another aspect of my work has focused on the interactions between fungi and bacteria in forest soils with the goal of determining how ecosystems with different fungal:bacterial ratios cycle nitrogen differently.  These projects have involved a number of interesting methodologies including molecular techniques such as Q‑PCR and T‑RFLPs to examine community structure as well as the use of stable isotopes to determine nitrogen cycling rates.

            Understanding the interactions of microbial communities with their environment is crucial to predicting how changes brought about by human activities - for example climate change - might impact the rates at which nutrients are cycled.  Research such as this also provides new insights into the natural distribution of microorganisms and the strategies that they possess to remain successful even under changing conditions.

Selected Publications:

Yarwood, S.A. and E.W. Sulzman. Submitted.  An activity to demonstrate soil microbial diversity in undergraduate biology classrooms.  Journal of Natural Resources and Life Science Education.

Boyle, S.A, R.R. Yarwood, P.J. Bottomley, D.D. Myrold. 2007. Bacterial and fungal contributions to soil nitrogen cycling under Douglas fir and red alder at two sites in Oregon. Soil Biology & Biochemistry. In Press. doi:10.1016/j.soilbio.2007.09.007

Boyle-Yarwood, S.A., P.J. Bottomley, D.D. Myrold. Submitted. Community composition and function of ammonia-oxidizing bacteria and archaea in acidic forest soils of the Pacific Northwest. Environmental Microbiology.

Yarwood, S.A., P.J. Bottomley, D.D. Myrold. In preparation. Microbial community structure and diversity differs under red alder and Douglas fir in a low and a high productivity forest soil.  Microbial Ecology.

Boyle, S.A., J. J. Rich, P.J. Bottomley, K. Cromack, D. D. Myrold. 2006.  Reciprocal transfer effects on denitrifying community composition and activity at forest and meadow sites in the Cascade Mountains of Oregon. Soil Biology & Biochemistry. 38:870-878

Bottomley, P.J., A.E. Taylor, S.A. Boyle, S.K. McMahon, J.J. Rich, K. Cromack, D.D. Myrold. 2004.  Responses of nitrification and ammonia oxidizing bacteria to reciprocal transfers of soil between adjacent coniferous forest and meadow vegetation in the Cascade Mountains of Oregon.  Microbial Ecology 48: 500-508.

Boyle, S.A. and S.L. Albrecht. 2002. Isolation and identification of bacteria in Eastern Oregon agricultural soils. Columbia Basin Agricultural Research Center Annual Report. Special Report 1040.