Sasha Wagner

Assistant Professor, Earth and Environmental Sciences

My research interests broadly focus on the geochemistry of organic matter, a fundamental component of carbon and biogeochemical cycles. As part of this research, I specialize in the study of black carbon, the fire-derived portion of organic matter. In my lab, we use a variety of analytical and chemical techniques to decipher the molecular information contained within organic matter and to advance our understanding of aquatic biogeochemistry in the face of environmental change.

If you are interested in joining my lab or learning more about the research we do, please contact me at the email listed below.


PhD in Environmental Chemistry, Florida International University, 2015

BS in Biochemistry, University of Delaware, 2009

Research Focus
  • organic geochemistry
  • biogeochemistry
  • environmental chemistry
  • dissolved organic matter
  • black carbon
Select Works
  • Wagner, S., Fair, J.H., Matt, S., Hosen, J., Raymond, P., Saiers, J., Shanley, J.B., Dittmar, T., Stubbins, A. (2019) Molecular hysteresis: Hydrologically driven changes in riverine dissolved organic matter chemistry during a storm event. Journal of Geophysical Research: Biogeosciences 123.
  • Wagner, S., Jaffé, R., Stubbins, A. (2018) Dissolved black carbon in aquatic ecosystems. Limnology and Oceanography: Letters doi: 10.1002/lol2.10076
  • Wagner, S., Brandes, S., Goranov, A., Drake, T.W., Spencer, R.G.M., Stubbins, A. (2017) Online quantification and compound-specific stable isotopic analysis of black carbon in environmental matrices via liquid chromatography-isotope ratio mass spectrometry. Limnology and Oceanography: Methods 15:995–1006. doi: 10.1002/lom3.10219
  • Wagner, S., Ding, Y., Jaffé, R. (2017) A new perspective on the apparent solubility of dissolved black carbon. Frontiers in Earth Science 5:75. doi: 10.3389/feart.2017.00075
  • Van Stan, J.T., Wagner, S., Guillemette, F., Whitetree, A., Lewis, J., Silva, L., Stubbins, A. (2017) Temporal dynamics in the concentration, flux, and optical properties of tree-derived dissolved organic matter (tree-DOM) in an epiphyte-laden oak-cedar forest. Journal of Geophysical Research: Biogeosciences 122:2982–2997. doi: 10.1002/2017JG004111
  • Wagner, S., Jaffé, R., Cawley, K., Dittmar, T., Stubbins, A. (2015) Associations between the molecular and optical properties of dissolved organic matter in the Florida Everglades, a model coastal wetland system. Frontiers in Chemistry 3:66. doi: 10.3389/fchem.2015.00066
  • Wagner, S., Riedel, T., Niggemann, J., Vähätalo, A.V., Dittmar, T., Jaffé, R. (2015) Linking the molecular signature of heteroatomic dissolved organic matter to watershed characteristics in world rivers. Environmental Science and Technology 49:13798–13806. doi: 10.1021/acs.est.5b00525
  • Wagner, S., Cawley, K.M., Rosario-Ortiz, F.L., Jaffé, R. (2015) In-stream sources and links between particulate and dissolved black carbon following a wildfire. Biogeochemistry 124:145–161.