1. Effects of Experimental Burning and Thinning on Soil Respiration and Belowground Characteristics Soung-Ryoul Ryu 1, Amy Concilio 1, Jiquan Chen 1, Deborah Neher 1, Siyan Ma 1 and Malcolm North 2 1 Department of EEES, University of Toledo, Toledo, OH 2 Department of Environmental Horticulture, University of California-Davis, Davis, CA

2. Objectives Is there relationship between soil respiration and root biomass? Is there relationship between soil respiration and root biomass? The relationship is the same under thinning and burning ? The relationship is the same under thinning and burning ? What controls root biomass ? What controls root biomass ? The driving factor is the same between treatments? The driving factor is the same between treatments? What affects soil respiration rate ? What affects soil respiration rate ? Any effects from thinning and burning ? Any effects from thinning and burning ?

3. Soil Climatic Factors Root Respiration (R a ) Soil Organic Matter Litter Layer Available Nutrient Soil Carbon Heterotrophic Respiration (R h ) Soil Chemical Factors Soil Respiration

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

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

6. Field Measurement Soil respiration rate (SRR; gCO 2 hr -1 m -2 ): a portable infrared gas analyzer (EGM-2 Environmental Gas Monitor, PP Systems, UK) Soil respiration rate (SRR; gCO 2 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 temperature at 10cm depth (Ts; ˚C): using a digital thermometer simultaneously with SRR measurement. Soil moisture (Ms; %): Time Domain Reflectometry (TDR) within 0~10cm depth in mineral soil. Soil moisture (Ms; %): Time Domain Reflectometry (TDR) within 0~10cm depth in mineral soil. Litter depth (LD) Litter depth (LD) Measured at least every other week during the growing season of 2002 Measured at least every other week during the growing season of 2002

7. Field Measurement Total nitrogen (TN) and total carbon (TC) content in soil: using CN analyzer (Carlo Erba NA 1500 Series 2) Total nitrogen (TN) and total carbon (TC) content in soil: using CN analyzer (Carlo Erba NA 1500 Series 2) pH: soil:H 2 O = 1:2 pH: soil:H 2 O = 1:2 Fine root biomass ( 2mm & 2mm & <2cm; CR) Soil samples were collected during June 25 to July 3, 2002 Soil samples were collected during June 25 to July 3, 2002

8. Effect of burning and thinning on the soil chemistry SourceDFSSMSF ValuePr > F TN (%) burn10.01 9.110.0028 thin20.00 1.060.3475 burn*thin20.00 1.540.2163 TC (%) burn10.02 1.240.2662 thin20.100.052.750.0655 burn*thin20.090.052.560.0787 CN burn13.77 23.97<.0001 thin24.132.0713.14<.0001 burn*thin20.450.221.430.2416 pH burn10.02 8.460.0039 thin20.120.0624.16<.0001 burn*thin20.040.026.950.0011

9. Effect of burning and thinning on the microclimate SourceDFSSMSF ValuePr > F SRR (gCO 2 hr -1 m -2 )burn11.06 99.50<.0001 thin20.130.076.340.002 burn*thin20.020.010.960.3841 Ts (˚C)burn10.27 118.58<.0001 thin20.850.43190.90<.0001 burn*thin20.070.0416.45<.0001 Ms (%)burn155.42 9.970.0018 thin295.3547.678.580.0002 burn*thin20.220.110.020.9805 LD (cm)burn13664.78 160.18<.0001 thin297.8448.922.140.1197 burn*thin2171.0485.523.740.0249

10. Effect of burning and thinning on the Root Biomass SourceDFSSMSF ValuePr > F FR010burn117.89 9.660.0026 thin211.535.773.110.0495 burn*thin26.063.031.640.2008 FR1020burn14.89 5.220.0248 thin213.546.777.220.0013 burn*thin28.804.404.690.0116 FRburn143.91 12.900.0006 thin249.6824.847.300.0012 burn*thin218.019.002.640.0769 CR010burn11.06 2.540.1144 thin20.330.170.400.6728 burn*thin20.360.180.430.6504 CR1020burn13.76 1.700.1955 thin215.497.743.500.0344 burn*thin210.795.402.440.093 CRburn17.11 2.770.0999 thin211.395.692.220.1152 burn*thin29.064.531.760.1777

11. Soil Respiration and Root Biomass SRR = f (FR010, FR1020, CR010, CR1020) SRR = f (FR010, FR1020, CR010, CR1020) Regression Coefficients r2r2 FR010FR1020CR010CR1020 UN 0.1270.1990.8000.013 0.063 UC 0.0150.790-0.6322.300 0.233 US 1.472-0.023-0.6151.569 0.390 BN -0.561-0.2501.8971.524 0.428 BC 0.011-0.2802.909-3.326 0.749 BS -1.5160.112-1.1211.751 0.553

12. Previous Results Lee and Jose (2003) found significant (α=0.05) correlation between SRR and fine root production Lee and Jose (2003) found significant (α=0.05) correlation between SRR and fine root production Populus deltoides 0.64 Populus deltoides 0.64 Pinus taeda 0.54 Pinus taeda 0.54 Pregitzer et al. (2003) showed that root N concentration explained 70% of variance in SRR

13. FR and Belowground Characteristics Path Coefficients TNTCpHTsMsLD UN0.110.33-0.330.06-0.060.40 UC0.660.170.68-0.25-1.15-0.49 US-0.090.090.300.800.44-0.25 BN-0.15-0.170.37-0.400.26-0.15 BC0.860.780.280.23-0.500.44 BS0.090.140.06-0.11-0.18-0.48 FR010

14. FR and Belowground Characteristics Path Coefficients TNTCpHTsMsLD UN0.130.09-0.22-0.070.10-0.10 UC0.62-0.040.310.70-2.110.23 US0.750.900.80-0.010.95-0.88 BN-0.82-0.48-0.23-0.67-0.58-0.07 BC0.380.340.270.12-0.560.15 BS0.300.430.28-0.54-0.07-0.46 FR1020

15. Path Analysis – SRR Path Coefficients CNpHFRCRTsMsLD UN0.22-0.230.200.220.29-0.450.29 UC0.050.130.14-0.09-0.73-0.110.45 US-0.38-0.400.46-0.290.960.010.73 BN-0.060.09-0.080.550.42-0.140.79 BC0.00-0.020.220.710.22-0.380.35 BS0.190.09-0.530.54-0.05-0.390.15

16. Conclusions Root biomass explained variance in SRR better in burned plots Root biomass explained variance in SRR better in burned plots Need for N analysis? Need for N analysis? Factors affecting fine root biomass changed by treatments Factors affecting fine root biomass changed by treatments At 0~10 cm At 0~10 cm Mostly climate factors – not clear; test w/ direct factors only At 10~20cm At 10~20cm Burned plots – climate factors/ unburned – nutrient factors SRR and Belowground characteristics SRR and Belowground characteristics Unburn – Climate factors Unburn – Climate factors / Burn only – LD / Burn and cut – Root biomass / Burn only – LD / Burn and cut – Root biomass

17. Acknowledgements Joint Fire Science Program Joint Fire Science Program Teakettle Experimental Forest Teakettle Experimental Forest Forest Service Forest Service LEES Lab, Dept of EEES, University of Toledo LEES Lab, Dept of EEES, University of Toledo A lot of helpers for the data collection A lot of helpers for the data collection

18. Questions? Any suggestions are welcome! If you are interested, you are welcome to get involved in this paper.

20. TN TC CN pH (box-whisker with Anova) ab ab a ab ab b a a b a a ac b ab ab ab a ab ab a ab b ab

21. SRR Ms Ts LD c c c ab a b a a b b a c ab a bc bc ab c c c c b a ab

22. FR CR 010 1020 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

23. 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 Kellogg. shrub dominant areas (CECO) Ceanothus cordulatus 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 study forest respectively (North et al. 2002). 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). 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). Soils are classified as Xerumbrepts and Xeropsamments (North et al. 2002).