Effects of Experimental Burning and Thinning on Soil Respiration and Belowground Characteristics

1
Effects of Experimental Burning and Thinning on
Soil Respiration and Belowground Characteristics

• Soung-Ryoul Ryu1, Amy Concilio1, Jiquan Chen1,
  Deborah Neher1, Siyan Ma1 and Malcolm North2
• 1Department of EEES, University of Toledo,
  Toledo, OH2Department of Environmental
  Horticulture, University of California-Davis,
  Davis, CA

2
Objectives

• Evaluate the effects of prescribed burning and
  thinning on soil chemistry, microclimate, root
  biomass, and soil respiration within mixed
  coniferous forest
• Evaluate the primary factors affecting root
  biomass and soil respiration rate under burning
  and thinning treatments.

3
Site Description

• Teakettle Experimental Forest
• 1300ha of area, located in Sierra National Forest
  on the west side of the Sierra Nevada range of
  California.
• Altitude 1980 2590 m
• Precipitation 1250mm/year, mostly in the form of
  snow
• Mean air temperature 1C(January ) and
  14.5C(July)

4
Plot Preparation

• Eighteen plots (4 ha each) were prepared using
  variogram and cluster analysis (North et al.
  2002).
• California spotted owl (CASPO) thinning, and
  shelterwood thinning were applied between August
  2000 and Summer of 2001
• Prescribed burning followed November 2001
• Transects (1m spaced) developed at
• Burn-CASPO (BC), Burn-Shelterwood (BS), Burn
  only (BN), Unburn-CASPO (UC), Unburn-Shelterwood
  (US), and Control (UN) plots

5
Field Measurement

• Soil respiration rate (SRR gCO2 hr-1 m-2) a
  portable infrared gas analyzer (EGM-2
  Environmental Gas Monitor, PP Systems, UK)
• Soil temperature at 10cm depth (Ts C) using a
  digital thermometer simultaneously with SRR
  measurement.
• Soil moisture (Ms ) Time Domain Reflectometry
  (TDR) within 010cm depth in mineral soil.
• Litter depth (LD)
• Measured at least every other week during the
  growing season of 2002

6
Field Measurement

• Total nitrogen (TN) and total carbon (TC) content
  in soil using CN analyzer (Carlo Erba NA 1500
  Series 2)
• pH soilH2O 12
• Fine root biomass (lt2mm FR) and coarse root
  biomass (gt2mm CR)
• Soil samples were collected during June 25 to
  July 3, 2002

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Effect of burning and thinning on the soil
chemistry
8
Effect of burning and thinning on the microclimate
9
Effect of burning and thinning on the Root Biomass
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TN TC CN pH (box-whisker with Anova)
ab ab a ab b ab
ab ab a ab ab b
a a b a a a
c b ab ab ab a
11
SRR Ms Ts LD
ab a bc bc ab c
c c c ab a b
a a b b a c
c c c b a ab
12
FR CR 010 1020
010 cm
b b ab b ab a
a a a a a a
1020 cm
c bc abc bc a ab
b ab ab b ab a
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Path Analysis on FR biomass at 010 cm
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Path Analysis SRR
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Conclusions

• Fine root biomass at 010cm was affected more by
  burning whereas fine root biomass at 1020cm were
  more affected by thinning
• Factors affecting fine root biomass can vary by
  intensity of thinning as well as the type of
  management treatments
• SRR was affected most by root biomass under
  burning thinning treatment, while by
  temperature at thinning only and by LD at burning
  only.

16
Acknowledgements

• Teakettle Experimental Forest
• Forest Service
• Joint Fire Science Program
• LEES Lab, Dept of EEES, University of Toledo

17
Questions?
18

• Soil respiration rate (SRR gCO2 hr-1 m-2) a
  portable infrared gas analyzer (EGM-2
  Environmental Gas Monitor, PP Systems, UK) with a
  SRC-1 Soil Respiration Chamber (PP Systems, UK).
• Soil temperature at 10cm depth (Ts C) using a
  digital thermometer (Taylor Digital Max/Min,
  Forestry Suppliers, Inc, USA) simultaneously with
  SRR measurement.
• Soil moisture (Ms ) Time Domain Reflectometry
  (TDR, model 6050XI. Soil Moisture Equipment
  Corp., Santa Barbara, California, USA) within
  010cm depth in mineral soil.

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Extra data

• This forest has three major patches,
• closed canopy by mixed conifer (CC),
• Ceanothus cordulatus Kellogg. shrub dominant
  areas (CECO)
• open canopy (OC).
• CC, OC, and CECO occupy the 67.7, 13.4, and 4.7
  of the entire study forest respectively (North et
  al. 2002).
• Major conifer species includes Abies concolor
  Lindl. ex Hildebr, A. magnifica A. Murr, Pinus
  lambertiana Douglas, P. jefreyi Grev. and Balf,
  and Calocedrus decurrens (Torr.) Florin (North et
  al. 2002).
• Soils are classified as Xerumbrepts and
  Xeropsamments (North et al. 2002).