The longleaf pine (Pinus palustris Mill.) ecosystem is one of the most diverse and endangered temperate ecosystems in North America. The native herbaceous species serve as fuel for the low-intensity, recurring fires the system depends on and thus play a major role in the maintenance of ecosystem structure. Soil microorganisms, such as bacteria and fungi, are known to aid greatly in many plant processes, including nutrient and water acquisition, resistance to infection, decomposition, and nutrient cycling. However, little is known about the relationship between dominant herbaceous species and soil bacterial compositions within montane longleaf pine ecosystems. In this preliminary study, we completed a multiyear, seasonal analysis of the soil bacterial microbiome composition upon removal of the two most dominant herbaceous species in a longleaf pine restoration site. The objective was to identify the major soil bacterial taxa and establish if changes occurred in their community structures following above-ground community manipulation. We also wanted to investigate relationships between bacterial community structure and environmental factors. Six randomized blocks (2.4m2) were established at Sheffield Wildlife Management Area in Paulding County, Georgia. Each block contained four subplots (50cm2), each with one of the following treatments: 1) control; 2) most dominant herbaceous species removed; 3) second most dominant herbaceous species removed; 4) soil disturbance: no species removed. DNA was extracted from soil samples from subplots each season and PCR amplified for bacterial gene sequences. Preliminary results indicated that the most abundant bacteria were Proteobacteria, Acidobacteria, and Actinobacteria, and soil bacterial relative abundances changed with plant removal and seasons. This information will serve as baseline data for future studies focused on the intricate relationships between ecologically important plants and their equally important microbial symbionts. Understanding these relationships will help inform the restoration process
