They're big, they're green and they're taking over a lake near you. What may look like a pretty wall of greenery may be threatening the growth of other plants around it. Barry Aronhime's CURE (Course-Based Undergraduate Research) lab is investigating the growing behavior of Colocasia escuelenta, or Elephant Ear, to see if other Louisiana native plants can outcompete this green, mean, fast growing machine.
CURE Labs: Real World Experience from the Start
The LSU College of Science offers a range of course-based undergraduate research or CURE labs, including labs in Biological Science (BIOL 1208R and 1209R) that allow students to gain the unique experience of working with faculty members and graduate students on research project of scientific significance. These labs enable students to learn the same scientific concepts that other students learn in regular biology labs, but in a more hands-on way.
“Undergrads are bored with cookie cutter labs. They want to do something that matters,” Barry Aronhime said. Barry is an instructor in the Department of Biological Sciences.
Sophomore pre-med student Camila Carrera was nervous about the work that the lab would require, but quickly realized that doing meaningful hands-on lab work was much more fulfilling than studying in a typical lab course. "Actually going out into the field to collect your own samples, taking trips to the greenhouse to see and measure the growth of your plants, and explaining the experimental process of something you've actually done are experiences you cannot learn from a textbook," Camila said.
Biological Sciences CURE labs are also Communication Intensive (CI) courses that build toward the Communication across the Curriculum (CxC) Distinguished Communicator program. These courses are designed to help students gain communication skills like writing and public speaking in their respective disciplines. CURE students create poster presentations on the research they conduct during the semester and are also encouraged to create social media posts with updates on their projects throughout the semester.
This semester, the Department of Biological Sciences offered 10 CURE lab sections for students to enroll in, incorporating a range of different research projects driven by LSU faculty members. Each faculty member involved designed a research project for which he or she enlists the help of students to conduct lab or field data collection and analysis. Research projects incorporated into CURE labs this semester involve examining and describing bacteria from the Gulf of Mexico (led by Cameron Thrash’s lab group), investigating Monarch butterfly’s food choices (led by Bret Elderd’s lab group), extracting DNA from coral (led by Morgan Kelly’s lab group), and examining how invasive Elephant Ear plants interact with native Louisiana plants.
The Fight to Survive
This semester, Barry Aronhime’s CURE labs are researching the growth patterns and behaviors of Colocasia escuelenta or Elephant Ear plants compared to several native Louisiana plants. Elephant Ear are commonly found in swamps and around lakes and have tall stalks and big, thick leaves that kind of look like … an elephant’s ear!
You might also see this plant listed as “wild taro” on wildlife and fisheries lists of invasive species. Wild taro can competitively displace native plants and is doing just that in Bluebonnet Swamp. It grows best in tropical environments, which makes it easy for it to flourish in south Louisiana. What’s not clear is how exactly it competes with and displaces other plants. Does it block the sunlight? Does it alter the available nutrients in the soil? CURE lab students are investigating possible explanations.
“My CURE students are working on a competition study with taro and a pair of native plants, arrow arum and pickerel weed. These are native to Louisiana but not very common in the Bluebonnet Swamp,” Barry said. “But where they are common, they grow fairly tall and very dense, so we want to see how well they can compete with taro in a controlled greenhouse.”
If these native species compete well enough, we may consider strategically planting these native species in Bluebonnet Swamp to see if they can slow the taro down.
About 60 biology CURE lab students, with help from members of the LSU AgCenter 4H Youth Wetlands Program, recently embarked on a field outing to dig up Elephant Ear on the banks of the LSU Lakes and Bluebonnet Swamp.
"I personally enjoyed taking the trip out to University Lake to harvest elephant ear," sophomore Jared Barrilleaux said. "Our research isn't confined to a classroom or lab, which makes the work we do all the more interesting."
Students cut off the green growth and harvested the corm (white part of the root), which they took back to the greenhouse and planted in clear containers with other native plants, including pickerel weed and arrow arum.
CURE students potted these plants in clear bins in seven different ways:
- Elephant Ear (EE), Arrow Arum (AA), and Pickerel weed (PW) together
- EE only
- PW only
- AA only
- EE and PW
- EE and AA
- AA and PW
CURE lab teaching assistant and LSU Museum of Science graduate researcher Ryan Burner explained that the bins with just one species planted in it will show how that species grows without any interactions with other species. These bins will serve as baseline measurements to compare to the bins that have varied species, to see if the different species are affecting each other's growth.
CURE students created seven replicates for each treatment, for a total of 49 bins overall with six plants in each, equally divided between species. The replicates were systematically distributed around the greenhouse to account for possible differences in conditions (sunlight, etc.) at different locations.
The students were divided into groups and each group is responsible for collecting data on three bins. Throughout the semester, these groups will observe the characteristics of wild taro growth to that of the native plants. They will measure characteristics like the height above the soil, length below the soil, the number of branches, how quickly the plants grow and more to see if the native plants can outcompete the invasive wild taro.
Check out the growth of the wild taro after two weeks!
Madeleine Gill’s group is monitoring the bins with arrow arum alone, pickerel weed alone and arrow arum and pickerel weed together. So far, her group has noticed that the arrow arum seems to be dying off, whereas the pickerel weed is surviving. As of now, her group thinks pickerel weed may have a better shot than arrow arum at competing with wild taro.
Tyler Hebert’s group has seen growth mainly from the wild taro. Tyler says he expected at least one of the native plants to be able to compete, but only some of their arrow arum has grown and almost none of their pickerel weed has sprouted.
The most growth Kami Menard’s group has seen is from their pickerel weed planted alone. The wild taro that was planted with the pickerel weed doesn't seem to be growing successfully, with some plants only growing a few centimeters in height so far.
Over the next few weeks, CURE students will learn how to best interpret their data and will come to a conclusion on how the native plants have competed with the wild taro.
To stay updated on this research project, follow the College of Science on our social media pages and check out the hashtag #LSUcure for updates on all the CURE lab projects.