2019 Konza LTER Summer REUs

Participant: Nicholas Vega Antuiano
Institution: Humboldt State University (senior in Rangeland Resource Science)
Advisor: Lydia Zeglin (Kansas State University)

The relationship between Arbuscular Mycorrhiza Fungi (AMF) and terrestrial vegetative life-spans to within the Phanerozoic Eon in the Paleozoic era during the Devonian period, making this relationship about 450 million years old. About 80% of the plants on earth have this AMF relationship. AMF are predominantly mutualistic with their host plant species, trading plant-fixed carbon for phosphorus and other plant essential nutrients. In some cases AMF will even provide protection for the host species. The role that plant-species-specific AMF relationships plays in the diversity of vegetation on landscapes has been examined in different aspects by interested investigators. Such investigations include those studying this phenomenon at Konza Prairie Biological Station (KPBS), which have suggested that the diversity of native plants within KPBS is associated with the presence of AMF due to host dependence on specific groups of AMF species. Subsequent studies have even alluded to the ability of some AMF relationships to exchange resources among other terrestrial plants.

The AMF association can be a belowground driver of aboveground ecosystem functions, such as the establishment and maintenance of dominant plant species populations, and thus may influence large-scale ecosystem changes like woody encroachment. Woody encroachment is responsible for grassland plant species displacement, and is present at KPBS, most prominently within experimental watersheds with different land management distinctions (specifically, low fire frequency). Is it possible that a species-specific AMF relationship can promote or maintain woody encroachment on watersheds within KPBS? Do woody encroachers and tall grasses have preferred AMF partners? Do management practices affect the AMF inoculum in the soil and thus the probability that woody plants can establish?

My investigation of these questions began this summer at KPBS working in the Zeglin lab with Principal Investigator Dr. Lydia Zeglin and Graduate student mentor Jaide Allenbrand. I collected paired root and bulk soil samples from nine experimental watersheds that included a factorial combination of annually and rarely burned, and bison grazed and ungrazed management treatments. The target plant species included two dominant woody encroachers roughleaf dogwood (Cornus drummondii) and eastern redcedar (Juniperus virginina), and two dominant grasses big bluestem (Andropogon gerardi) and Indian Grass (Sorghastrum nutans). I extracted DNA from the root and soil samples, and amplified the fungal ITS gene from all samples using PCR. The PCR product was then further cleaned-up and combined into a single fungal library (including both soil and root DNA extracts), and sent for DNA sequencing (Illumina MiSeq). The resulting sequence data are complete and high-quality; however, this work took longer than 8 weeks so I am still corresponding with Dr. Zeglin to work through the data analysis and results. We are eager to learn whether any pattern in fungal species commonalities exists in the target plant species and soils with contrasting management. AMF symbionts may play a crucial role in mediating plant community compositional shifts, and data like these could provide an indicator for rangeland health observations and management decisions.

My time spent in the Zeglin Lab and at KPBS has been a rewarding experience that has certainly fostered my continued growth as a scientist. I am very thankful for those in the Zeglin Lab for the continuous support I received, which provided me with the resources and stability needed to hone my scientific discipline. Additionally, I gained a deep respect for my peers in the Zeglin Lab as they facilitated and reciprocated scientific maturity, friendship and community. Iron sharpens iron. I hope to one day offer a quality research opportunity of this caliber to students of my own one day- giving them these experiences, leading them through the growing pains and providing a summer well spent.

Participant: Matt Turnley
Institution: Simpson College (senior in Environmental Science and Business Management)
Advisor: Melinda Smith (Colorado State University) and Leena Vilonen (Ph.D. student)

During the summer 2019, I examined the impacts that both drought and high precipitation levels on soil nutrients in a tallgrass prairie. Attending a small, liberal arts school, it was incredibly helpful to gain insight into all of the work being done by larger, more research-focused universities, and partaking in research on the Konza Prairie was truly a dream come true. Each week I took soil respiration and soil moisture measurements, gaining valuable experience in both field work and data management. Throughout the summer, I also had the opportunity to help with soil coring/sieving, species composition work, and various other soil analyses in labs at Kansas State University and Colorado State University. My specific work took advantage of recent precipitation patterns, and compared soil respiration, soil moisture, C:N ratios, total organic carbon, and nitrogen/carbon mineralization between a drought year and a high precipitation year. Changes in precipitation levels and increased drought periods are projected impacts of climate change -- so understanding the effects of these climate changes is of great interest, particularly in an ecosystem that has already been largely destroyed by humans. I feel very fortunate to have had this opportunity, and not only learned a lot about soil chemistry, but also about the graduate school process, working with others, and the many fascinating processes that occur in a tallgrass prairie.

Participant: Miguel Duarte
Institution: Arizona State University (senior in Biological Sciences)
Advisor: Meghan Avolio (Johns Hopkins University)

During my internship, I was fortunate enough to study traits of plants in several long-term nutrient addition experiments at the Konza Prairie Biological Station. The goal of the project was to see how traits of species differ over space and time between grasses and forbs, in response to ongoing N experiments at the Konza Prairie. Over the summer, I collected 6 individuals of 6 plant species (1 individual per species) across 3 experiments (ChANGE, P-Plots, NutNet), totaling 288 above-ground plant samples. While in the field, I took measurements of shoot length (cm), shoot diameter at base (mm), and the number of fully developed leaves on each shoot. Samples were immediately taken back to the lab for further measurements. From each shoot, I then found the youngest fully developed leaf to record its wet weight (g), leaf length (cm), leaf thickness (inches), and leaf toughness (g of sand required to tear leaf). Root samples were also collected, 2 individuals per subplot, one for the most dominant grass and one for the most dominant forb across all experiments. Dried shoot, leaf, and root masses were also recorded. Apart from my own project, I also assisted other researchers at Konza when I had the chance. I also spent time helping a graduate student collect samples for predawn and midday water potential measurements. I also assisted with the new ConSME project at KPBS with insecticide applications to the herbivore removal plots over the course of several days. This internship was a great experience because I able to work alongside many other researchers and with a great team, building my skills.

Participant: Aditi Arun
Institution: Kansas State University (senior in Biology)
Advisor: Kent Connell (Ph.D. student in John Blair's lab - Kansas State University)

This summer I was offered an amazing REU opportunity to expand my knowledge in the area of Ecological research. My research was based on soil carbon dynamics and how they are affected by the different photosynthetic pathways that are utilized by the plants. For this, I, along with my mentor Kent, visited Konza and collected samples from two plots, one of which was woody encroached and the other was still in grassland. The experience of working in the field felt amazing. This research opened up gates to new experiments and handling new types of equipment and now, I can most definitely say that I learned more about it and know more than I started off with. All this was possible only because of my REU mentor Kent, who gave me the opportunity to work on the project over the summer. Having an amazing mentor like him made the research more fun and I'm really grateful to have gotten this opportunity.

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