Photo of Joanna Blaszczak, Extension

Joanna Blaszczak

Assistant Professor

Summary

I am interested in the transport and transformation of nutrients and contaminants through watersheds and the streams that drain them. I use a combination of field, laboratory, and modeling approaches to test ecological theory and controls on water quality in human-dominated landscapes.

A central goal of my research is to improve understanding of how increasing hydroclimatic variability and land use change in the Anthropocene will alter the capacity of watersheds and freshwater ecosystems to retain, transform, and alter novel chemical mixtures. In previous research, I investigated the effects of multiple stressors in urban watersheds (e.g. contamination, excess nutrients, increased extremes in hydrologic flow regimes) as fundamental drivers of stream ecosystem function.

Questions that guide my current and future work include:

  1. What is the role of novel chemical regimes (i.e. ‘chemical cocktails’) in shaping the response of freshwater ecosystems to land use change?
  2. How do changes in watershed land use and hydrologic connectivity alter the chemical regimes of freshwater ecosystems?
  3. What processes determine the magnitude and timing of freshwater ecosystem energetics and how are ecosystem energetics changing in the Anthropocene?

Education

B.S. Cornell University, 2011
Ph.D. Duke University, 2018

News & Journal Articles, Fact Sheets, Reports...

Journals
Macroscale controls determine the recovery of river ecosystem productivity following flood disturbances Lowman, H. E., Shriver, R. K., Hall, R. O., Harvey, J. W., Savoy, P., Yackulic, C. B., & Blaszczak, J. R 2024, Proceedings of the National Academy of Sciences, 121(5), e2307065121
Models of underlying autotrophic biomass dynamics fit to daily river ecosystem productivity estimates improve understanding of ecosystem disturbance and resilience. Blaszczak, J. R., Yackulic, C. B., Shriver, R. K. & Hall Jr, Robert. 2023, Ecology Letters
At the interfaces of the hydrologic sciences: Connecting water, elements, ecosystems, and people through the major contributions of Dr. Emily Bernhardt. Helton, A. M., Morse, J. L., Sudduth, E. B., Ardón, M., Bier, R., Voss, K. A., Ross, M. R., Blaszczak, J. R., Brandt, J. E., Simonin, M., Rocca, J. D., Carter, A., Gerson, J. R., Ury, E. A., & Vlah, M. J. 2023, Journal of Hydrology, 619, 129251
Deoxygenation of temperate rivers J. R. Blaszczak 2023, Nature Climate Change, Nature, vol. 13(10), pages 1021-1022, October
Freshwater Salinity Regimes Bolotin, L. A., J. R. Blaszczak 2022, HydroShare
Hypoxia dynamics and spatial distribution in a low gradient river. Carter, A. M., Blaszczak, J. R., Heffernan, J. B., & Bernhardt, E. S. 2021, Limnology and Oceanography.
Aquatic ecosystem metabolism as a tool in environmental management. Jankowski, K. J., Mejia, F. H., Blaszczak, J. R., & Holtgrieve, G. W. 2021, Wiley Interdisciplinary Reviews: Water, e1521
A Classification Framework to Assess Ecological, Biogeochemical, and Hydrologic Synchrony and Asynchrony. Seybold, E. C., Fork, M. L., Braswell, A. E., Blaszczak, J. R., Fuller, M. R., Kaiser, K. E., … Zimmer, M. A. 2021, Ecosystems, 1–17
Zero or not? Causes and consequences of zero-flow stream gage readings Margaret A Zimmer, Kendra E Kaiser, Joanna R Blaszczak, et. al. 2020, WIRES Water Volume7, Issue3
Watershed urban development controls on urban streamwater chemistry variability Joanna R Blaszczak, Joseph M Delesantro, Ying Zhong, Dean L Urban, Emily S Bernhardt 2019, Biogeochemistry volume 144, pages61–84
Scoured or suffocated: Urban stream ecosystems oscillate between hydrologic and dissolved oxygen extremes Joanna R. Blaszczak, Joseph M. Delesantro Dean L. Urban Martin W. Doyle Emily S. Bernhardt 2019, Limnology and Oceanography Volume 64, Issue 3
Sediment chemistry of urban stormwater ponds and controls on denitrification Blaszczak, J. R., M. K. Steele, B. D. Badgley, J. B. Heffernan, S. E. Hobbie, J. L. Morse, E. N. Rivers, S. J. Hall, C. Neill, D. E. Pataki, P. M. Groffman, and E. S. Bernhardt. 2018, Ecosphere 9(6):e02318. 10.1002/ecs2.2318
Reviews
Catchment concentration–discharge relationships across temporal scales: A review. Speir, S. L., Rose, L. A., Blaszczak, J. R., Kincaid, D. W., Fazekas, H. M., Webster, A. J., Wolford, M. A., Shogren, A. J., & Wymore, A. S. 2023, Wiley Interdisciplinary Reviews: Water, e1702.