Hutchins, B.T., Engel, A.S., Nowlin, W.H., Schwartz, B.F. (2016) Chemolithoautotrophy supports subterranean food webs and affects regional diversity and long-term stability of stygobiont communities. Ecology. 97: 1530–1542. DOI: doi/10.1890/15-1129.1/.
Hutchins, B.T., Engel, A.S., Nowlin, W.H., Schwartz, B.F. (2016) Biodiversity, stability, and trophic complexity in the Edwards Aquifer, United States: The influence of chemolithoautotrophy on stygobiont community structure. International Conference for Subterranean Biology, Fayetteville, Arkansas. June 12-17, 2016. p. 44. http://www.speleobiology.com/icsb2016/wp-content/uploads/bsk-pdf-manager/ICSB_2016_Abstracts_2.pdf
Hutchins, B., Schwartz, B., Engel, A.S. (2013) Environmental controls on organic matter production and transport across surface-subsurface and geochemical boundaries in the Edwards Aquifer, Texas, USA. Acta Carsologica 42/2-3: 245–259.
Gray, C.J., Engel, A.S. (2013) Microbial diversity and impact on carbonate geochemistry across a changing geochemical gradient. ISME Journal. 7: 325:337. DOI:10.1038/ismej.2012.105.
Engel, A.S., Randall, K.W. (2011) Experimental evidence for microbially-mediated carbonate dissolution from the saline water zone of the Edwards Aquifer, Central Texas. Geomicrobiology Journal. 28(3): 313-327.
Birdwell, J.E., Engel, A.S. (2010) Characterization of dissolved organic matter in cave and spring waters using UV-Vis absorbance and fluorescence spectroscopies. Organic Geochemistry. 41: 270-280.
Birdwell, J.E., Engel, A.S. (2009) Variability in terrestrial and microbial contributions to dissolved organic matter fluorescence in the Edwards Aquifer, Central Texas. Journal of Cave and Karst Studies. 71: 144-156. (includes published cover photograph for the issue)
Engel, A.S. (2009) Sulfur-rich karst systems, in Palmer, A.N. and Palmer, M.V. (eds.), Caves and Karst of the USA. National Speleological Society: Huntsville, Alabama, p. 404.
Porter, M.L., Engel, A.S. (2008) Balancing the conservation needs of sulphidic caves and karst with tourism, economic development, and scientific study: Cave and Karst Science. 35:19-24.
Engel, A.S., Hutchins, B., Nowlin, W., Schwartz, B.F. (2018) Profiling the functional diversity of microbial communities to understand the development and maintenance of the Edwards Aquifer ecosystem. Geological Society of America Abstracts with Programs. Indianapolis, IN; 50(6), doi: 10.1130/abs/2018AM-322716.
Engel, A.S., Hutchins, B., Schwartz, B., Gray, C., Birdwell, J.E. (2011) Evidence for a non-terrigenous food web base in the Edwards Aquifer, Texas. National Speleological Society Convention, Glenwood Springs, Colorado, July 16-24. (oral presentation)
Hutchins, B., Schwartz, B. Engel, A.S. (2011) Linking hydrogeology, geochemistry, and microbiology to food web dynamics in the biodiverse phreatic karstic Edwards Aquifer, TX, USA. North American Benthological Society; Providence, Rhode Island. May 22 – 26. (poster presentation)
Gray, C., Engel, A.S. (2009) Changes in microbial diversity along a geochemical gradient in the Edwards Aquifer, Texas: Possible implications for aquifer modification and ecosystem processes. AGU Annual Meeting, San Francisco, CA: ID# B23C-0392.
Birdwell, J.E., Schulz, C., Engel, A.S. (2008) Chromophoric dissolved organic carbon from cave and karst waters, in Kato, K., and Kimura, H., 7th International Symposium for Subsurface Microbiology, Shizuoka, Japan, p. 62. (oral presentation)
Birdwell, J.E., Engel, A.S. (2008) Changes in the fluorescence of chromophoric dissolved organic matter in a central Texas aquifer between extreme climatic events, in Kato, K., and Kimura, H., 7th International Symposium for Subsurface Microbiology, Shizuoka, Japan, p. 37 (poster presentation).
Birdwell, J., Schulz, C., Engel, A.S. (2007) Autochthonous dissolved organic matter in karst waters: Evidence from fluorescence spectroscopy. Eos Trans. American Geophysical Union, 88(52), Fall Meet. Suppl., Abstract H43C-1511. (poster presentation)
Engel, A.S., Randall, K.W. (2006) Microbial colonization and weathering of carbonates in deep subsurface settings. International Mineralogical Association, Kobe, Japan, p. 248. (Invited oral presentation)
Randall, K.W., Johnson, L., Engel, A.S. (2005) Assessing the potential impact of microbes in the Edwards and Trinity aquifers of Central Texas. GSA Abstracts with Programs, 37: 217. (poster presentation)