What the flux? Achieving success in undergraduate-faculty research on soil respiration

Background/Question/Methods

Conducting research on carbon dioxide dynamics can be challenging at an undergraduate institution.  The high cost of equipment and the conceptual difficulty many undergraduates have with studying seemingly invisible ecosystem processes can be barriers to success.  Overcoming these challenges, however, is possible and beneficial to all involved. We report on the process of developing a successful undergraduate-faculty collaborative research project on soil respiration that resulted in a peer-reviewed publication.  We believe thorough preparation, co-intellectual ownership, and high organization by Johnson (student) and Bowne (faculty) were major determinants of success. Working off Bowne’s initial idea, Johnson conducted a literature review in fall 2010 on how land use affects soil respiration and developed a research proposal to test the hypothesis that soil carbon dioxide efflux would be greater in residential lawns than corn fields.  Johnson, with Bowne’s guidance, measured soil carbon dioxide efflux, soil temperature, and soil moisture once a week for ten weeks in the fall of 2011 with a LI-8100.  This equipment was obtained through LI-COR’s Environmental Education Fund (LEEF) with funds from a Science in Motion grant from the Commonwealth of Pennsylvania to Elizabethtown College.  Johnson worked with Bowne to learn appropriate statistical analyses such as repeated measures ANOVA and multiple linear regression.

Results/Conclusions

We found soil carbon dioxide efflux occurring in residential lawns was significantly higher (F_1,6=7.46, p=0.034) than the levels in corn fields for the entirety of the study. Soil carbon dioxide efflux significantly decreased over time in both land use types (F_9,54=37.34, p<0.001).  Soil temperature, soil moisture, and land use type significantly contributed to the efflux (R²=0.744, F_3,76=73.44, p<0.001).  Johnson reported these results while enhancing her writing skills by composing a senior honors thesis for Elizabethtown College in the spring semester of 2012.  In the fall of 2012, Bowne furthered the analysis and worked with Johnson to prepare a manuscript that was ultimately published (Bowne, D.R. and E. Johnson. 2013. Comparison of soil carbon dioxide efflux between residential lawns and corn fields. Soil Science Society of America Journal. doi:10.2136/sssaj2012.0346N).  Our results suggest the conversion of agricultural land to residential lawns could increase soil carbon dioxide release per unit area of soil, especially if soils warm because of urbanization.  In addition to the scientific merit of our research, we believe the steps in achieving the success of our undergraduate-faculty collaboration can be informative for others seeking a model on which to base undergraduate research.