Summer research projects in labs and field sites provide opportunities for hands-on research.

Forest Structure and Composition, Ground Cover, and Soil Characteristics Along Cross-Sectional Gradients in Leon and Salado Creek Greenways

Students (n=16) were trained in basic forest mensuration techniques using the point-quarter method to analyze forest structure and composition, including identification of shrubs and trees, in Leon and Salado Creek greenways in San Antonio. Soils were collected from all plots and analyzed for organic matter, organic carbon, and nitrogen. Ground cover was also evaluated in all plots to analyze species richness and diversity of herbs and grasses. Sampling occurred along 16 cross-sections of the greenways that included sampling the east upper slope, east mid-slope, east dry creek, west dry creek, west mid-slope, and west upper slope. The objectives of the study are to compare differences in vegetation and soils along different gradient and aspects of the greenway. In addition, the students assisted a MS Thesis student comparing riparian shrubs in trees in Leon and Salado Creek greenways.
Students: Tracy Cabrera, Alyssa Cook, Alicia Elizalde, David Lind, Cesar Lopez, Natalie Martinez, Ysabel Morales, Jodie Phipps, Sara Pecha, Laura Salazar, Ananya Seth, Lorraine Shanahan, Jasmine Stanley, Jazmine Tijerina, Benjamin Weber, and Bailey Williams
Time Frame: 2024 to 2026

Analysis of Allochthonous Leaf Litter Accumulation in Ephemeral Pools in Leon Creek Greenway (on-going study)

Students (n=4) collected organic litter in 12 ephemeral pools in Leon Creek, San Antonio, Texas during the Spring of 2024 as part of on-going study to compare seasonal carbon input from allochthonous sources. The samples collected were sorted in the lab by type (plant species, twigs, shells, fruits/seeds, and humus), dried, and analyzed from percent organic matter and carbon. The goal of the study is to analyze organic debris input by type in ephemeral pools in association with drought and periods of normal precipitation. Each future cohort of students will collect organic litter samples from the same plots to build the database in a long-term study of energy input into ephemeral streams and isolated pools. The next sampling periods for organic matter collection is planned for November 2024 and the spring of 2025.
Students: Alyssa Cook, Alicia Elizalde, Natalie Martinez, and Jasmine Stanley
Time Frame: 2024 to 2026

Protists and Algae Taxa Richness and Diversity from Rehydrated Biofilms Within an Ephemeral Stream in Leon Creek Greenway

Biofilm collected from Leon Creek during a drought was maintained in the lab at ambient conditions, and rehydrated in July 2024. Four treatments (control, nitrogen, phosphorous, and nitrogen+phosphorous) and five replicates of dry biofilm were placed in distilled water and monitored at 0, 1, 2, and 4 weeks. Basic water quality variables (temperature, pH, conductivity, ORP, organic carbon, and total nitrogen) were analyzed at weeks 0, 1, 2, and 4. Counts of protists and algae by genus were counted over the four week period to analyze which taxa are most resilient to drought. Additional biofilms studies will be started during 2025 and 2026.
Students: Alyssa Cook, Alicia Elizalde, Natalie Martinez, Laura Salazar, and Kennedy Wood
Time Frame: 2024 to 2026

Microplastics Concentrations in Forest Soils and in Algae Mats from Roadway Runoff

Eight students (n=10) were trained in collection, digestion, density separation, filtering, and identification of microplastics from water, soils, and biofilms. Maddion Orquiz, from EcoJEDI cohort 1, has completed analysis of microplastics in 250 soil samples from Bent Creek Experimental Forest and is working on the statistical analysis which she plans to submit to a peer-reviewed journal. During the summer of 2024, five students began analyzing microplastic concentration in algae mats from roadside runoff. An additional study examining microplastics in sunflowers is planned to start in October 2024.
Students: Alyssa Cook, Alicia Elizalde, Anna Gonzalez, Anna Jaud, Natalie Martinez, Ressa Martinez, Ihunanya Okechukwu, Christiana Ramos, Angel Velasquez, and Bailey Williams
Time Frame: 2024 to 2026

Documenting the Plant Species Present in the Upper Section of Leon Creek Greenaway

Students (n=5) spent time during the summer entering the data (species, common name, functional group, wetland status, etc.) in an Excel spreadsheet from pressed native and non-native grasses (n=89 species) and herbs (n > 240 species) collected from Central Texas for a future herbarium at UTSA. The goal is to submit a flora survey manuscript to a peer-reviewed journal and develop a link on the EcoJEDI website with photos and descriptions of the vegetation in the upper reach of Leon Creek.
Students: Tracy Cabrera, Anna Darcy, Natalie Martinez, Lorraine Shanahan, and Jasmine Stanley
Time Frame: on-going

Forest Structure and Composition Used by Porcupines for Diurnal Rest Trees

This field study evaluated the forest structure and composition used by porcupines for diurnal rest trees and compared adjacent habitat to evaluate if porcupines were selecting a specific type of tree or habitat for diurnal rest sites. Students used the variable plot sampling method with a prism to estimate forest characteristics that included mean tree density, d.b.h, basal area, canopy cover and height, biomass, and carbon sequestration. Students gained experience in identifying the trees found in Central Texas forests.
Students: Julianna Collins, Sierra Jaramillo, Kate Kampman, and Angle Velasquez
Time Frame: 2023, will be expanded to Leon and Salado Creek during 2024-25

Evaluation of Upland and Riparian Plant Restoration Project in a Spring Run Backed Up by Sediment Accumulation Above a Dam

This field study evaluated an upland and riparian plant restoration project on private land in Johnson City, Texas. Silt had built up above the dam and the area above the dam became invaded with an invasive aquatic grass. Students used the line transect method to document the coverage of plants by species in a site that was replanted 5 years ago from the upland, transitional, riparian, and aquatic ecotones. The collected data was compared to coverage of the plants at the time of the initial restoration when the riparian and upland habitat was primarily bare mineral soil. EcoJEDI students will continue to assist with the evaluation each summer of the program. Claire Littlefield is doing her MS thesis research on microplastics in biofilm and collected biofilms during the monitoring.
Students: Hailey Avalos and Claire Littlefield
Time Frame: 2018 to present, evaluations will occur every three years

Analysis of Allochthonous Leaf Litter Accumulation in Ephemeral Pools

This field study involved collecting leaf litter and humus from 0.25 m2 plots (n = 36) in isolated pools (n = 12) in an ephemeral streams. The leaf litter samples were sorted by species (plant type, twigs, wood, seed, fruits, etc.) and dried, then analyzed for organic matter and carbon with the Loss-on-Ignition method. This study is a long-term project that will include future EcoJEDI students in evaluating the biomass and carbon content of allochthonous organic matter seasonal movement into ephemeral streams in relation to droughts and floods. Excessive organic matter input into aquatic systems can be a source of pollution as it increases microorganism breakdown of organic matter along with increased respiration which results in decreased O2 concentrations and the release of CO2 into the atmosphere. With the recent droughts and record high temperatures in 2022 and 2023 experienced in Central Texas, the early senescence of leaves on deciduous trees and perennial forbs and grasses may result in impaired water quality associated with climate warming. Future EcoJEDI cohort will participate in this long-term study gaining field and lab experience and working with a large data set.
Students: Jazmine Blancas, Julianna Collins, Sierra Jaramillo, Kate Kampman, Claire Littlefield, and Angle Velasquez
Time Frame: 2022 to present, sample will be collected each summer and winter for six additional years

Meiofauna Taxa Richness and Diversity in Isolated Pools Within an Ephemeral Stream in Leon Creek Greenway

This field study analyzed meiofauna and protozoa in isolated pools within an ephemeral stream in Leon Creek Greenway. This study was a master's thesis research. Filamentous algae, biofilms, and water samples were collected from 12 pools. Water quality variables were collected from each pool that included temperature, pH, electrical conductivity, dissolved solids, dissolved oxygen, oxidation reduction potential, organic carbon, and total nitrogen. Meiofauna and protozoa were identified in the lab with a compound microscope at 4x using multiple keys. Various diversity indexes will be used to test for differences among the pools.
Students: Jazmine Blancas and Claire Littlefield
Time Frame: 2022 to 2023