Investigating the Impact of Prescribed Burning on Carbon, Nitrogen, pH, and Microbial Community Diversity

1. Investigating the Impact of Prescribed Burning on Carbon, Nitrogen, pH, and Microbial Community Diversity By Bobby Riley

3. Introduction • Prescribed burning is the deliberate use of fire under specified and controlled conditions to achieve a resource management goal • Previous studies of forest soil ecosystems have shown that prescribed burning alters the physical and chemical properties of the soil such as carbon and nitrogen balance and increased pH values • Prescribed burns has also been known to impact microbial biomass and activities. • A number of factors determine the ability of a microorganism to thrive in an environment • pH, carbon, nitrogen, temperature, O2

4. pH is the measure of the acidity or alkalinity of a solution • Most soil bacteria grow best at pH near neutral, or a pH of 7 • The major function of microorganisms is to degrade organic matter and transform carbon to form CO2 for photosynthesis • Carbon is the element essential for all living things • To utilize this carbon, nitrogen is required • Nitrogen is essential for microbial growth and for organic matter decomposition.

5. Background of Study Site • The study site was the William B. Bankhead National Forest located on the Southern Cumberland Plateau region of the southern Appalachian Mountains. • Bankhead National Forest has 180,000 acre of land. • It was hit by Southern Pine Beetle for decades and epidemic peaked in 2000 resulting in 22,000 acres of dead pine forest (Gaines and Creed, 2003).

6. Blocks I, II, and IV Treatment 1: Control (No burn) Treatment 3: Control with 3-year burn interval

7. Soils • The area has a moderately deep, well drained and permeable soil type. • Sipsey series • O horizon • A horizon O A E Bt C

8. Objectives • Determine the microbial community diversity in a fire managed forest ecosystem. • Determine carbon and nitrogen content and pH in soil from a fire managed forest ecosystem. • Evaluate relationships between C, N, pH, and microbial community diversity.

9. Hypotheses • The microbial community composition will change due to prescribed burning • Prescribed burning will affect the C, N, and pH of the soil.

10. Field Methods • The samples were collected from T1(control) and T3 (after burn) located in Blocks I, II, and IV • The samples were collected from the O and A horizons • They were stored in labeled Ziploc bags • The samples were then prepared for analysis

11. Materials/Methods(Microbial Community Diversity) • Extraction of Soil DNA using the MOBIO PowerSoil DNA Isolation Kit • Quantification of DNA using the Nanodrop • Polymerase Chain Reaction (PCR) with universal primers 338f and 518r • Gel Electrophoresis • 1% agarose gel with ethidium bromide

12. PCR Purification • Qiagen Purification Kit • Cloning • Topo TA Cloning Reaction • One Shot Chemical Transformation • Analysis of Positive Clones • Sequencing • BigDye Termination Kit v3.1 Cycle Sequencing Kit (Appied Biosystems {ABI}

13. Materials/Methods(Carbon/Nitrogen and pH Analysis) • Carbon and Nitrogen were determined by combustion with Elementar CNS Analyzer. • pH was determined by using the 2:1 soil-water ratio and a pH meter

14. RESULTS

19. Discussion/Conclusions • There was a relationship between pH values and the amount of DNA present in each sample • There were differences in the contents of carbon and nitrogen in the O and A horizons • No clear impacts of prescribed burning on pH, C, and N contents of soils were observed. • Community diversity analysis is yet to be completed

20. Acknowlegments • Dr. Elica M. Moss • Dr. Monday Mbila • Dr. Maria Nobles • National Science Foundation • Alabama A&M University

21. Questions