Termite mounds are reported to increase soil quality in savannas because termites collect detritus and return it to their mounds. Soil fertility should therefore decrease with increasing distance from termite mounds. This may have consequences for the species and abundance of grasses growing on the site. The intent of this study was to examine soil respiration and grass diversity surrounding termite mounds within the Wits Rural Facility, near Acornhoek, South Africa. We hypothesized that sites closer to the termite mounds would have increased levels of soil respiration along with greater diversity of plant species. We also tested for the relationship between the most abundant grass species, Panicum maximum, and mound distance. The biomass of P. maximum was predicted to decrease with increasing distance away from the mound. After locating three termite mounds, we collected soil samples at increasing distances away from each mound. Soil fertility was assessed by soil CO2 respiration. Additionally, grass biomass and number of plant species was measured at each soil collection site. We found that there was a strong negative correlation (r= -0.66) between soil fertility and distance from the mound. No correlation was found between grass species richness and distance from the mound. However, there was a strong negative correlation (r= -0.80) between the amount of P. maximum and distance from the mound. Our results support our hypotheses that soil fertility and P. maximum abundance would be greater closer to the termite mounds.
Termite mounds reportedly increase soil quality in South African savannas, potentially affecting surrounding grass species and abundance. We hypothesized that sites closer to termite mounds would have increased levels of soil respiration along with greater diversity of plant species. The biomass of the grass Panicum maximum was also predicted to have an inverse relationship with mound distance. Soil samples were collected at increasing distances away from three mounds and assessed for soil fertility by soil CO2 respiration. Grass biomass and number of plant species was also measured at each soil collection site. Both soil respiration and P. maximum biomass had a strong negative correlation with mound distance, supporting our hypotheses that soil fertility and P. maximum abundance would be greater closer to the termite mounds.
Boyer, S., & Roberts, J. (2019). Islands of fertility: termite mounds enhance soil and grass richness in South African savannahs. https://oaks.kent.edu/node/7946
Boyer, Sarah, and Jessica Roberts. 2019. “Islands of Fertility: Termite Mounds Enhance Soil and Grass Richness in South African Savannahs”. https://oaks.kent.edu/node/7946.
Boyer, S., and J. Roberts. Islands of Fertility: Termite Mounds Enhance Soil and Grass Richness in South African Savannahs. 9 Apr. 2019, https://oaks.kent.edu/node/7946.