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

Belowground Belowground CharacteristicsCharacteristics

Soung-Ryoul RyuSoung-Ryoul Ryu11, Amy Concilio, Amy Concilio11, Jiquan Chen, Jiquan Chen11, , Deborah NeherDeborah Neher11, Siyan Ma, Siyan Ma11 and Malcolm and Malcolm

NorthNorth22

11Department of EEES, University of Toledo, Department of EEES, University of Toledo, Toledo, OHToledo, OH

22Department of Environmental Horticulture, Department of Environmental Horticulture, University of California-Davis, Davis, CAUniversity of California-Davis, Davis, CA

ObjectivesObjectives

Evaluate the effects of prescribed Evaluate the effects of prescribed burning and thinning on soil chemistry, burning and thinning on soil chemistry, microclimate, root biomass, and soil microclimate, root biomass, and soil respiration within mixed coniferous respiration within mixed coniferous forest forest

Evaluate the primary factors affecting Evaluate the primary factors affecting root biomass and soil respiration rate root biomass and soil respiration rate under burning and thinning treatments. under burning and thinning treatments.

Site Description Site Description

Teakettle Experimental Forest Teakettle Experimental Forest 1300ha of area, located in Sierra 1300ha of area, located in Sierra

National Forest on the west side of the National Forest on the west side of the Sierra Nevada range of California. Sierra Nevada range of California.

Altitude: 1980 ~ 2590 m Altitude: 1980 ~ 2590 m Precipitation: 1250mm/year, mostly in Precipitation: 1250mm/year, mostly in

the form of snow the form of snow Mean air temperature: 1°C(January ) Mean air temperature: 1°C(January )

and 14.5°C(July) and 14.5°C(July)

Plot Preparation Plot Preparation Eighteen plots (4 ha each) were Eighteen plots (4 ha each) were

prepared using variogram and prepared using variogram and cluster analysis (North et al. cluster analysis (North et al. 2002). 2002).

California spotted owl (CASPO) California spotted owl (CASPO) thinning, and shelterwood thinning, and shelterwood thinning were applied between thinning were applied between August 2000 and Summer of August 2000 and Summer of 2001 2001

Prescribed burning followed Prescribed burning followed November 2001 November 2001

Transects (1m spaced) Transects (1m spaced) developed atdeveloped at Burn-CASPO (BC), Burn-Burn-CASPO (BC), Burn-

Shelterwood (BS), Burn only (BN), Shelterwood (BS), Burn only (BN), Unburn-CASPO (UC), Unburn-Unburn-CASPO (UC), Unburn-Shelterwood (US), and Control (UN) Shelterwood (US), and Control (UN) plots plots

Field Measurement Field Measurement Soil respiration rate (SRR; gCOSoil respiration rate (SRR; gCO22 hr hr-1-1 m m-2-2): a ): a

portable infrared gas analyzer (EGM-2 portable infrared gas analyzer (EGM-2 Environmental Gas Monitor, PP Systems, UK)Environmental Gas Monitor, PP Systems, UK)

Soil temperature at 10cm depth (Ts; ˚C): using Soil temperature at 10cm depth (Ts; ˚C): using a digital thermometer simultaneously with SRR a digital thermometer simultaneously with SRR measurement. measurement.

Soil moisture (Ms; %): Time Domain Soil moisture (Ms; %): Time Domain Reflectometry (TDR) within 0~10cm depth in Reflectometry (TDR) within 0~10cm depth in mineral soil. mineral soil.

Litter depth (LD) Litter depth (LD) Measured at least every other week during the Measured at least every other week during the

growing season of 2002 growing season of 2002

Field Measurement Field Measurement

Total nitrogen (TN) and total Total nitrogen (TN) and total carbon (TC) content in soil: using carbon (TC) content in soil: using CN analyzer (CN analyzer (Carlo Erba NA 1500 Carlo Erba NA 1500 Series 2) Series 2)

pH: soil:HpH: soil:H22O = 1:2 O = 1:2 Fine root biomass (<2mm; FR) and Fine root biomass (<2mm; FR) and

coarse root biomass (>2mm; CR)coarse root biomass (>2mm; CR) Soil samples were collected during Soil samples were collected during

June 25 to July 3, 2002June 25 to July 3, 2002

Effect of burning and Effect of burning and thinning on the soil thinning on the soil

chemistrychemistry

0.00116.950.020.042burn*thin 

<.000124.160.060.122thin

0.00398.460.020.021burnpH

0.24161.430.220.452burn*thin 

<.000113.142.074.132thin

<.000123.973.773.771burnCN

0.07872.560.050.092burn*thin 

0.06552.750.050.102thin

0.26621.240.020.021burnTC (%)

0.21631.540.000.002burn*thin 

0.34751.060.000.002thin

0.00289.110.010.011burnTN (%)

Pr > FF Value MSSSDFSource 

Effect of burning and Effect of burning and thinning on the microclimatethinning on the microclimate

0.02493.7485.52171.042burn*thin 

0.11972.1448.9297.842thin

<.0001160.183664.783664.781burnLD (cm)

0.98050.020.110.222burn*thin 

0.00028.5847.6795.352thin

0.00189.9755.4255.421burnMs (%)

<.000116.450.040.072burn*thin 

<.0001190.900.430.852thin

<.0001118.580.270.271burnTs (˚C)

0.38410.960.010.022burn*thin 

0.0026.340.070.132thin

<.000199.501.061.061burnSRR (gCO2 hr-1 m-2)

Pr > FF Value MSSSDFSource 

Effect of burning and thinning on the Effect of burning and thinning on the Root BiomassRoot Biomass

0.17771.764.539.062burn*thin 

0.11522.225.6911.392thin

0.09992.777.117.111burnCR

0.0932.445.4010.792burn*thin 

0.03443.507.7415.492thin

0.19551.703.763.761burnCR1020

0.65040.430.180.362burn*thin 

0.67280.400.170.332thin

0.11442.541.061.061burnCR010

0.07692.649.0018.012burn*thin 

0.00127.3024.8449.682thin

0.000612.9043.9143.911burnFR

0.01164.694.408.802burn*thin 

0.00137.226.7713.542thin

0.02485.224.894.891burnFR1020

0.20081.643.036.062burn*thin 

0.04953.115.7711.532thin

0.00269.6617.8917.891burnFR010

Pr > FF Value MSSSDFSource 

TN TC CN pH (box-TN TC CN pH (box-whisker with Anova)whisker with Anova)

0.00

0.20

0.40

0.60To

tal N

itro

ge

n (

%)

0

5

10

Tota

l Ca

rbo

n (

%)

BC BS BN UC US UN

Treatment

15

20

25

30

35

C:N

ra

tio

BC BS BN UC US UN

Treatment

4

5

6

7

8

pH

H2O

ab ab a ab ab b

a a b a a a

c b ab ab ab a

ab ab a ab b ab

SRR Ms Ts LDSRR Ms Ts LD

0

1

2

3S

oil

Re

spir

atio

n R

ate

(g

CO 2

hr-1

m-2)

10

15

20

25

So

il M

ois

ture

(%

)

BC BS BN UC US UN

Treatment

10

15

20

25

30

So

il Te

mp

era

ture

(°C

)

BC BS BN UC US UN

Treatment

0

5

10

15

20

25

Litt

er

De

pth

(cm

)

c c c ab a b

a a b b a c

ab a bc bc ab c

c c c b a ab

FR CR 010 1020 FR CR 010 1020

0.00

0.50

1.00

1.50

2.00F

ine

Ro

ot

Bio

ma

ss (

kg m

-2)

0.00

0.50

1.00

1.50

2.00

Co

ars

e R

oo

t B

iom

ass

(kg

m-2)

BC BS BN UC US UN

Treatment

0.00

0.50

1.00

1.50

2.00

Fin

e R

oo

t B

iom

ass

(kg

m-2)

BC BS BN UC US UN

Treatment

0.00

0.50

1.00

1.50

2.00

Co

ars

e R

oo

t B

iom

ass

(kg

m-2)

a a a a a a

b ab ab b ab a

c bc abc bc a ab

b b ab b ab a

0~10 cm

10~20 cm

Path Analysis on FR biomass at Path Analysis on FR biomass at

0~10 cm0~10 cm

0.40-0.060.06-0.330.330.11UN

-0.250.440.800.300.09-0.09US

-0.49-1.15-0.250.680.170.66UC

-0.150.26-0.400.37-0.17-0.15BN

-0.48-0.18-0.110.060.140.09BS

0.44-0.500.230.280.780.86BC

LDMsTspHTCTNCorrelation

Path Analysis – SRR Path Analysis – SRR

Conclusions Conclusions

Fine root biomass at 0~10cm was affected Fine root biomass at 0~10cm was affected more by burning whereas fine root biomass more by burning whereas fine root biomass at 10~20cm were more affected by thinning at 10~20cm were more affected by thinning

Factors affecting fine root biomass can vary Factors affecting fine root biomass can vary by intensity of thinning as well as the type of by intensity of thinning as well as the type of management treatments management treatments

SRR was affected most by root biomass SRR was affected most by root biomass under burning + thinning treatment, while under burning + thinning treatment, while by temperature at thinning only and by LD at by temperature at thinning only and by LD at burning only. burning only.

Acknowledgements Acknowledgements

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

of Toledoof Toledo

Questions?Questions?

Soil respiration rate (SRR; gCOSoil respiration rate (SRR; gCO22 hr hr-1-1 m m-2-2): a portable ): a portable infrared gas analyzer (EGM-2 Environmental Gas infrared gas analyzer (EGM-2 Environmental Gas Monitor, PP Systems, UK) with a SRC-1 Soil Monitor, PP Systems, UK) with a SRC-1 Soil Respiration Chamber (PP Systems, UK). Respiration Chamber (PP Systems, UK).

Soil temperature at 10cm depth (Ts; ˚C): using a Soil temperature at 10cm depth (Ts; ˚C): using a digital thermometer (Taylor Digital Max/Min, digital thermometer (Taylor Digital Max/Min, Forestry Suppliers, Inc, USA) simultaneously with Forestry Suppliers, Inc, USA) simultaneously with SRR measurement. SRR measurement.

Soil moisture (Ms; %): Time Domain Reflectometry Soil moisture (Ms; %): Time Domain Reflectometry (TDR, model 6050XI. Soil Moisture Equipment (TDR, model 6050XI. Soil Moisture Equipment Corp., Santa Barbara, California, USA) within Corp., Santa Barbara, California, USA) within 0~10cm depth in mineral soil. 0~10cm depth in mineral soil.

Extra data Extra data This forest has three major patches, This forest has three major patches,

closed canopy by mixed conifer (CC), closed canopy by mixed conifer (CC), Ceanothus cordulatus Ceanothus cordulatus Kellogg. shrub dominant areas (CECO) Kellogg. shrub dominant areas (CECO) open canopy (OC). open canopy (OC).

CC, OC, and CECO occupy the 67.7, 13.4, and 4.7% of the entire CC, OC, and CECO occupy the 67.7, 13.4, and 4.7% of the entire study forest respectively (North et al. 2002). study forest respectively (North et al. 2002).

Major conifer species includes Major conifer species includes Abies concolorAbies concolor Lindl. ex Hildebr, Lindl. ex Hildebr, A. A. magnificamagnifica A. Murr, A. Murr, Pinus lambertianaPinus lambertiana Douglas, Douglas, P. jefreyiP. jefreyi Grev. and Grev. and Balf, and Balf, and Calocedrus decurrensCalocedrus decurrens (Torr.) Florin (North et al. 2002). (Torr.) Florin (North et al. 2002).

Soils are classified as Xerumbrepts and Xeropsamments (North et Soils are classified as Xerumbrepts and Xeropsamments (North et al. 2002).al. 2002).