Micronutrients, hurricanes, and invasive species: insights into the micronutrient limitation and stress of an invasive ant along the coast of Texas
Human activities associated with climate change are rearranging the distribution of elements and species across the globe, but the consequences of these alterations remains unknown. Coastal ecosystems are likely at risk to an increase in the intensity and frequency of large tropical storms. These storms often deposit large amounts of micronutrients, which are less abundant in living tissue, and can affect the abundance and diversity of arthropods. Little is known, though, how additions of micronutrients can affect the success of consumers, especially invasive arthropods. To determine how changes in biogeochemistry affects litter arthropods, we utilized a factorial, fertilization experiment that manipulated macro- (N&P) and micronutrients (Ca, K, and Na; 16 treatments x 8 replicates = 128 plots), in 2016 and 2017, in large 30 m x 30 m plots in a coastal tallgrass prairie near Houston, TX. We collected litter arthropods using pitfall traps in 2017, and one year post-fertilization in 2018. Based on results from 2017, we conducted feeding trials, that manipulated the ratio of Ca:Na (by 10%, 25%, and 40%) in food, on an invasive ant, Nylanderia fulva in 2018. In 2017, N. fulva was the dominant litter arthropod across all treatments, and their abundance was limited by Ca, but tends to be suppressed by Na. In 2018, however, these effects disappeared as soil cations were likely leached from the soil, and abundance of N. fulva dropped 98%, likely due to Hurricane Harvey. Preliminary lab results show that manipulating the Ca:Na ratio in the food of N. fulva affects colony fitness, indicating that Na can reach toxic levels, suppressing colony size, while Ca ameliorates these toxic effects. These results indicate that changes in micronutrient availability may facilitate the success of an invasive species, and gives insight as to how human activities are altering coastal ecosystems.
Kathleen A Kargl, Chelse M Prather
Primary Advisor's Department
Stander Symposium poster
"Micronutrients, hurricanes, and invasive species: insights into the micronutrient limitation and stress of an invasive ant along the coast of Texas" (2019). Stander Symposium Posters. 1653.