Understanding Microbial Trait Responses to Increased Sea Level Rise Along a Coastal Forest Boundary

Ashton J. Rush*, Nannete Raczka and Edward Brzostek, Department of Biology, West Virginia University, Morgantown, WV 26505

Field (Broad Category): Biology (Biological & Biochemical Sciences) 

Student’s Major: Biochemistry 

As the Earth’s climate is changing, the effects of these changes on ecosystem functions may in turn exacerbate the changing pace. Soils hold a large stock of carbon, and microbes drive the extent of how much may be stored or respired, potentially adding more carbon dioxide to the atmosphere. As sea levels rise, a large uncertainty is how the increase in salinity from the ocean water may affect soil microbes in riparian zones. This project is studying the extent to which the increase in salinity impacts riparian soil microbes. This experiment was conducted by taking soil samples from multiple plots of varying salinity (low, medium, and high) and placing them in opposing soil locations. We performed an assay to measure the extracellular enzyme activity to acquire labile carbon, nitrogen, phosphorous from the soil. We hypothesize that the soils from the different salinities will all show a decreased efficiency in any new environment due to increased levels of stress from the drastic increase or decrease of salinity in the water. In measuring enzyme activity, we found that soil origin drove microbial response in different saline environments. The soil exchanged from the high to low salinity regions had higher enzyme activity to acquire carbon, nitrogen and phosphorous than in high saline conditions. When soil exchanged from medium to low salinity, enzyme activity was reduced. This research is important in understanding how microbes in the soil respond to salinity, which could aid in predicting how soil carbon will respond to global change. 

Funding: Smithsonian Institute 

Program/mechanism supporting research/creative efforts: WVU's Research Apprenticeship Program (RAP) & accompanying HONR 297-level course