Congratulations to our 2020 John Spencer Research Grant recipients!

The River Basin Center John Spencer Research Grants support graduate students affiliated with the RBC with small grants of up to $2,000. This program was launched in 2016 with a generous donation from Kathleen Amos, and is named in honor of her son, John Spencer, a former master’s student at the River Basin Center and Odum School of Ecology.

Donations to this fund are currently being accepted through the River Center Fund. Please include RBC Spencer Grants in the Special Instructions on page two of the form.

Meet this year’s recipients

Carolyn Cummins

I am a PhD student in Dr. Amy Rosemond’s lab, and my research is focused on the effects of temperature on stream ecosystems. Specifically, I am interested in how stream insects respond to temperature and how these responses may scale up to affect ecosystem processes like leaf litter breakdown. I am originally from Durango, Colorado and attended Colorado State University. I have always been interested in the natural world, and this was nurtured further after I got involved with research and had the opportunity to do field work late in my undergraduate career. I switched my focus from pre-vet to Ecology, and the rest is history! In my spare time, I enjoy cycling, hiking, rock climbing, and cooking!


Ranjit Bawa

My research includes two general and overlapping areas of interest. First is how modeling non-point source (NPS) pollution influences water quality, especially as it pertains to the role of human interaction. Second, I am interested in advancing economic applications as it relates to agent behavior in the context of decision-making under uncertainty and ultimately, policy design. My most recent work attempts to value changes in water yields by surveying Georgia landowners whose forests serve as watersheds for the provision of critical ecological services (i.e. increased water yields). I am originally from the Boston area and worked in finance before returning to school for graduate studies in Statistics and Agricultural Economics some years later. Most recently, I was based in Minneapolis prior to starting my research program at the University of Georgia. In my spare time, I enjoy exploring new hiking trails around northeast Georgia and basketball.


Derrick Platero

My project is a detailed characterization of soil physical properties, which are critical inputs for modeling landscape-scale water table fluctuations. Spatial predictions of these properties with depth at the field-scale are often related to microtopography, which can be represented with detailed topographic indices. Proximal sensing techniques like electrical resistivity tomography (ERT) and electromagnetic Induction (EMI) are more useful in identifying subsurface features associated with changes in ground conductivity. EMI has been used to quantify a variety of soil properties including texture, moisture, and pH. The objective of this research was to create detailed maps of sand, silt, and clay by depth for a 50-acre crop field in a Georgia Piedmont floodplain using a combination of depth-averaged specific conductance from EMI and topographic indices derived from lidar. We will develop spatial predictions of soil texture for each increment using regression-kriging and random forest models, and will compare them to available data in soil surveys. Models will be validated using k-fold cross validation. The resulting maps will be used to direct a subsequent sampling effort focused on soil hydraulic properties and water table modeling. Soil texture maps are an essential part of the soil assessment framework which can support advances in sensor technology and computer modeling. I am from the Navajo Nation located in New Mexico. I completed my undergraduate degree with a Bachelors in Agriculture in Soil Science with a minor in geology at New Mexico State University. I am currently working on my M.S. in Soil Science at UGA and plan to do my PhD after completion. I have a passion for Geo sciences–specifically soil science, hydrology, geology, and agriculture.


Laura Kojima

I am a first year Master’s student in the CESD program in Odum and my research is focused on alligator ecotoxicology and movement behavior. I am currently looking at the frequency with which alligators on the Department of Energy’s Savannah River Site move on and off the site to public hunting grounds and whether this puts hunters/consumers at risk of contaminant exposure. This is done through GPS/telemetry and biological sample collection. The funding from RBC will also contribute to looking at the potential for alligators to act as biological vectors for contaminants through a captive study, in which we collect feces, analyze it for contaminant off-loading, and compare contaminant levels to that of other biological samples such as blood and tail muscle. I have a research background in herpetology, and am originally from California, where I worked with western pond turtles during my undergraduate degree at UC Davis. Right after graduation, I worked with USGS on their giant gartersnake project for a season then took a few months off before moving for grad school. 

The Role of Freshwater Crabs in Neotropical Streams

Freshwater crabs play an important role in the breakdown of nutrients from natural materials that fall into streams, but few studies have looked into exactly how their relationships with other detritivores and the leaf litter itself impacts ecosystems.  

River Basin Center graduate student Carol Yang shed light on these relationships in neotropical streams in two recently published papers.

In a paper published in Freshwater BiologyYang did an in-stream experiment in Monteverde, Costa Rica to examine the leaf litter in enclosures that contained crabs as compared to enclosures without crabs. One dynamic that Yang and colleagues hoped to learn more about was the relationship between crabs and other detritivores—which contribute to leaf breakdown, but that crabs frequently prey upon. 

Throughout the study, Yang and collaborators regularly sampled the leaf litter. They found that enclosures with crabs had faster rates of breakdown than those without, indicating that their manipulation and consumption of leaves had a larger impact than their consumption of other detritivores and shredders. 

In a follow up study published in Nauplius, Yang used a laboratory setting to gain a more in-depth understanding of the crab behaviors that most impacted leaf litter. The crabs were collected from Monteverde, Costa Rica, and transported to aquariums along with unfiltered stream water and leaves from a common subcanopy tree. 

Yang and colleagues found that the leaf mass was significantly higher in tanks with crabs than those without. They also used visual observations and recordings to watch as the crabs used their claws to grasp and shred the leaves, which aided in ingestion. At the end of the experiment, they observed that leaves in tanks with crabs were broken up into multiple pieces, whereas leaves in tanks without them remained whole.    

These studies suggest that crabs play an important role in helping to process the detritus that accumulates in neotropical streams, especially given their abundance in tropical streams. 

Dr. Krista Capps Tops the Charts

Congratulations to Dr. Krista Capps, a River Basin Center affiliate and professor at the University of Georgia, who authored the most read article of Freshwater Science within the past 12 months. Her research article, “Poverty, urbanization, and environmental degradation: urban streams in the developing world”, focuses on how an increase in urbanization is affecting the water resources of lower-income countries. Capps and her colleagues highlight the importance of integrative technologies and management techniques to best understand urban watersheds in these developing areas. Her publication has topped the charts, and UGA is proud of Capps’ continuing success. 

Link to Dr. Krista Capps’ Study: https://www.journals.uchicago.edu/doi/abs/10.1086/684945

Written by: Cammie Caldwell