Discipline: Ecology Environmental and Earth Sciences
Subcategory: Geosciences and Earth Sciences
Room: Park Tower 8212
Chloe Cromer - University of North Georgia
Co-Author(s): Tim Ohlert, University of New Mexico, Albuquerque, New Mexico
The effects of vegetation change on soils remains a relatively understudied topic. Currently, in New Mexico and many arid biomes around the world, grasslands are being encroached upon by woody shrubs like the Creosote bush (Larrea tridentata). Typically, woody shrub encroachment upon grasslands is considered negative to ecosystem health; studies have shown that as the Creosote bush encroaches upon Black Grama (Bouteloua eriopoda) dominated grasslands there is a variable decline in overall ecosystem health attributable to a decline in plant biomass, increased soil erosion, and a loss of integral soil nutrients and function. In this study, we hope to reveal the specific impacts of plant community composition change on soil functions, and whether soil properties facilitate these vegetation transformations. Additionally, we want to identify trends within plant-soil interactions that can be used as a tool to predict future vegetation and soil dynamics in arid biomes. We gathered soil samples across ecosystems of the Sevilleta National Wildlife Refuge, these specific biomes are dominated by Black Grama, Blue Grama (Bouteloua gracilis), and Creosote. We sampled and tested soils from each site for water holding capacity, soil stability, percent bare ground, percent organic matter, and chlorophyll content. In addition, we collected soils from an ongoing long-term dominant species removal experiment within the refuge designed to examine the long-term response of semi-arid vegetation communities to the removal of dominant species. We hypothesized that the dominant species of the grassland ecosystems would incur greater soil fertility and stability due to greater carbon inputs and reduced erodible bare ground. We found soil properties attributable to the different dominant grassland and shrubland species within the Sevilleta National Wildlife Refuge. The interconnection of different soil properties provides evidence for site-specific trends that could be used to predict the future of plant vegetation among drylands. The results of this study could have implications for rangeland management, restoration, and desertification across drylands both regionally and globally.
Funder Acknowledgement(s): National Science Foundation (NSF), University of New Mexico
Faculty Advisor: Tim Ohlert, firstname.lastname@example.org
Role: The research experiment was designed by me and my mentor Tim Ohlert. Though during the time I was in my REU I went out into the field and collected each of the soil samples on site and I was the one who processed most if not all of the data for our variables (water holding capacity, soil stability, percent bare ground, percent organic matter.) Chlorophyll content data was generated with help of my mentor Tim Ohlert and some of the undergraduates students at the Rudgers-Whitney lab at UNM. Data assessment was done both by me and my mentor Tim Ohlert through RStudio.