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

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

• By Bobby Riley

2
(No Transcript)
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 21 soil-water
  ratio and a pH meter

14
RESULTS
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
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 AM University

21
Questions