Effects of Simulated Climate Change on Native Southeastern Grassland Vegetation Using Open Top Chambers

Author

Makaila CarpenterFollow

Date of Award

Summer 2024

Document Type

Thesis

Degree Name

Master of Science (MS) in Biology

Department

Biology

Committee Chair

Tenzing Ingty

Abstract

The southeastern United States is a critical biodiversity hotspot once covered in prairie grassland ecosystems and now facing significant threats due to urbanization, habitat destruction, over-exploitation, biological invasions, pollution, and climate change. This study analyzes the response of Alabama’s native prairie ecosystem to climate change. We used open top chambers (OTCs) to simulate climate change-induced warming. We assessed the response of ecosystem function and structure to higher temperatures (1-3^oC). The indicators of ecosystem function included phenology, leaf surface area (LSA), specific leaf area (SLA), and aboveground and below net primary productivity (ANPP and BNPP respectively). Ecosystem structure was evaluated based on species diversity and composition. Our results showed ecosystem function in the OTC was significantly lower based on LSA, SLA, and leaf biomass. Although not statistically significant, ANPP and BNPP were also higher in control plots. We documented altered phenology in several species including early flowering and increase in the length of the growing season. We also documented decreased species diversity in the OTCs and the inability of some species to establish under the warmer conditions. Our results exemplify the negative effects of climate change on native prairie vegetation. Reduced ecosystem function has cascading impacts and will threaten food resources for other species, especially at higher trophic levels, thus putting at risk our already vulnerable prairie ecosystems. Moreover, a decline in healthy plants in an ecosystem will also alter ecosystem services like carbon sequestration, soil stabilization, and water cycle regulation. Changes in ecosystem services and biodiversity will also directly affect our food security.