Fine Root Dynamics

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Fine Root Dynamics Progress at the Waycross
Sites

• Tracey Crocker
• Ron Hendrick

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Objectives

• To understand the mechanisms by which competition
  control and fertilization affect loblolly pine
  fine root production and turnover.
• Quantify treatment differences in fine root
  biomass, production, lifespan and morphology

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Variables under study

• Biomass
• Cores to a 10 cm depth for root lengths, masses,
  and densities.
• Growth Dynamics
• Use minirhizotrons to measure fine root
  production and mortality.
• Morphology
• Extraction of intact root segments from forest
  floor and mineral soil for topological analysis

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Biomass of size classes
C
F
H
HF
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Growth Dynamics
Minirhizotron Tube
Digital Camera
Camera Controller
Hi-8 VCR
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Length vs. Number Pinus elliottii Productivity
Regression
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Length vs. Number Liquidambar styraciflua
Productivity Regression
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Length vs. Number Pinus glauca Productivity
Regression
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Length vs. NumberRegression Across Sample
Species Treatments
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Findings to date...

• Total root mass varies such that F gtC gtH gtHF
• Ratio of fine to coarse root mass C gtF gtHF
  gtH
• Ratio of wood volume to fine roots mass is
  higher
• with increasing treatment intensity
• (HFgtHgtFgtC)

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Findings to date...

• Ratio of leaf area to fine root mass and length
  is higher
• with increasing treatment intensity
• (HFgtHgtFgtC)
• Substituting root numbers for length yields a
  good
• relationship and may significantly cut
  processing time
• of minirhizotron video taped images.