Research Interests

1. Biogeochemical cycling of natural organic matter in contemporary and paleo-ecosystems, with a particular focus on understanding interactions between human activities and natural cycles of organic matter;
2. Human impacts on water quality, with current projects including:
   1. organic and inorganic nutrient exports from agricultural watersheds
   2.  fingerprinting organic matter in streams to determine the impacts of septic effluents on surface waters
   3. impacts of coal mining on groundwater quality in China
3. Water quality-quantity connectivity, such as watershed exports of dissolved organic matter and inorganic nutrients during storm events;
4. Terrestrial-aquatic linkages through organic matter;
5. Biomarker records of mass extinctions recorded in Late Devonian black shales.

Among the most common tools include: 1) biomarkers, i.e., source-specific and resistant organic molecules that can record environmental and ecological processes over geological time scales, 2) stable and radiogenic isotopes (13C, 14C, 15N), 3) optical properties of organic matter (three dimensional fluorescence, absorption); and 4) ultra-high resolution FTICR-MS analysis.

Research Group Members

Current Students

• Man Lu (PhD student, Fall 2015- present) “Wildfires during the Late Devonian recorded in black shales”
• Shuo Chen (PhD student, Fall 2016-present) “Effects of extreme climatic events on terrestrial-aquatic biogeochemical connectivity”
• Olivia Warren (MS student, Fall 2017-present) “Geochemical tracers of water sources in glacier-fed rivers in Tibet”
• Jian Chen (PhD student, Fall 2018-present) “Paleoenvironmental reconstructions from the Late Devonian black shales ”
• Mary Puckett (MS student, Fall 2018-present, co-advised with Dr. Yong Zhang) “Kinentics of nutrients and heavy metals moving in streams within and across spatial scales”

Previous Team Members

• Zachary Stephens (Undergraduate researcher, 2015 – 2017) “Storm mobilization of carbon and nitrogen  within a forested watershed”
• Siera Jann (Undergraduate researcher, 2015 – 2017) “Fossil reptile or plant remains? Mysterious organic matter from the Jurassic Morrison Formation of Western Colorado”
• Yue Hu (PhD 2017, Peking University, China) “Watershed exports of organic matter in a large agricultural basin in arid northwestern China”
• Daniel Fields (MS 2013, University of Alabama) “Hydrocarbon degradation in coastal oceans” now Geologist at Alabama Department of Environmental Management (ADEM)
• Xiaping Li (MS 2014, University of Alabama) “High-resolution molecular characterizations of stream water DOM in forested and agricultural watersheds”
• Connor Kirkland (undergraduate researcher, 2015 – present) “Dissolved organic matter in ponds across an age spectrum”
• Peng Shang (PhD, 2019) “Watershed and hydrological controls of organic matter and nutrients in lotic ecosystems”

Visiting Professors

• Dr. Wenli Zhong (June 2015 to June 2016; from College of Earth Sciences, Chengdu University of Science and Technology, China) “Geomorphological controls on the amount and quality of dissolved organic matter in an unregulated river, Alabama”
• Dr. Fengxia Liu (October 2016 to October 2017; from Dalian University of Science and Technology, China) “Dissolved organic matter composition and quality in Alaska aquifers”

Other Experiences

• NOAA Summer Fellow, NOAA Great Lakes Enviromental Research Laboratory, 2006 (Fish Ecology)  & 2007 (Ecotoxicology)
• Integrated Ocean Drilling Expedition 333 Shipboard Scientist in Organic Geochemistry, Dec 2010-Jan 2011
• Chief Scientist Training Cruise, UNOLS, July 2011
• Guest Investigator, Woods Hole Oceanographic Institution, 2017-2018
• Editorial Board member for American Chemical Society Earth and Space Chemistry http://pubs.acs.org/journal/aesccq