General Site Information
Site ID:US-Ton
Site Name:Tonzi Ranch
Tower Team: PI: Dennis Baldocchi <Baldocchi@berkeley.edu> - University of California, Berkeley
FluxContact: Siyan Ma <syma@berkeley.edu> - University of California, Berkeley
Technician: Joe Verfaillie <jverfail@berkeley.edu> - University of California, Berkeley
Latitude:38.4316
Longitude:-120.9660
Elevation (m):177
NetworkAmeriFlux
IGBP:WSA (Woody Savannas)
Climate Koeppen:Csa (Mediterranean: mild with dry, hot summer)
Mean Annual Temperature (degrees C):15.8
Mean Annual Precipitation (mm):559
Data Products: AmeriFlux BASE Dataset
FLUXNET2015 Dataset
FLUXNET LaThuile Dataset
Data Availability: AmeriFlux BASE:   15 years (Duration: 2001 - 2015)
FLUXNET2015:   14 years (Duration: 2001 - 2014)
FLUXNET LaThuile:   6 years (Duration: 2001 - 2006)
Data Downloads to Date: AmeriFlux BASE:   208 unique downloads
FLUXNET2015:   523 unique downloads
FLUXNET LaThuile:   258 unique downloads
Data DOIs: AmeriFlux BASE DOI: 10.17190/AMF/1245971
Description:Located in the lower foothills of the Sierra Nevada Mountains, the Tonzi Ranch site is classified as an oak savanna woodland on privately owned land. Managed by local rancher, Russell Tonzi, brush has been periodically removed for cattle grazing. The overstory is dominated by blue oak trees (40% of total vegetation) with intermittent grey pine trees (3 trees/ha). Understory species include a variety of grasses and herbs, including purple false brome, smooth cat's ear, and rose clover. These two distinctive layers operate in and out from one another. Growing season of the understory is confined to the wet season only, typically from October to early May. In contrast, the deciduous blue oak trees are dormant during the rainy winter months and reach maximum LAI in April. The blue oak ecosystem rings the Great Central Valley of California, inhabiting the lower reaches of the Sierra Nevada foothills.
Acknowledgments:This research was supported by the US Department of Energy Terrestrial Carbon Program, grant No. DE-FG03-00ER63013 and DE-SC0005130
Site image(s):
For additional AmeriFlux site images, see the Web site gallery

Publications relevant to understanding the site
BibliographyUsage
Baldocchi D, Chen Q, Chen X, Ma S, Miller G, Ryu Y, Xiao J, Wenk R, Battles J (2010) The Dynamics of Energy, Water and Carbon Fluxes in a Blue Oak (Quercus douglasii) Savanna in California, USA. In: Hanan MJHaNP (ed) Ecosystem Function in Global Savannas: Measurement and Modeling at Landscape to Global Scales. CRC/Taylor and Francis Reference
Baldocchi D, Ma S, Rambal S, Ourcival JM, Limousin JM, Misson L, Pereira J, Papale D (2010) On the Differential Advantages of Evergreenness and Deciduousness in Mediterranean Oak Woodlands: A Flux Perspective. Ecological Applications in press Reference
Baldocchi DD, Xu L (2007) What limits evaporation from Mediterranean oak woodlands - The supply of moisture in the soil, physiological control by plants or the demand by the atmosphere? Advances in Water Resources 30:2113-2122 Reference
Baldocchi, D. D., L. Xu, and N. Kiang (2004), How plant functional-type, weather, seasonal drought, and soil physical properties alter water and energy fluxes of an oak-grass savanna and an annual grassland, Agricultural and Forest Meteorology, 123(1-2), 13-39. Primary_Citation
Baldocchi, D., Q. Chen, X. Chen, S. Ma, G. Miller, Y. Ryu, J. Xiao, R. Wenk, and J. Battles (2010), The Dynamics of Energy, Water and Carbon Fluxes in a Blue Oak (Quercus douglasii) Savanna in California, USA, in Ecosystem Function in Global Savannas: Measurement and Modeling at Landscape to Global Scales, edited by M. J. H. a. N. P. Hanan, CRC/Taylor and Francis. Reference
Baldocchi, D., Q. Chen, X. Chen, S. Ma, G. Miller, Y. Ryu, J. Xiao, R. Wenk, and J. Battles (2010), The Dynamics of Energy, Water and Carbon Fluxes in a Blue Oak (Quercus douglasii) Savanna in California, USA, in Ecosystem Function in Global Savannas: Measurement and Modeling at Landscape to Global Scales, edited by M. J. H. a. N. P. Hanan, CRC/Taylor and Francis. Primary_Citation
Chen Q, Baldocchi D, Gong P, Dawson T (2008) Modeling radiation and photosynthesis of a heterogeneous savanna woodland landscape with a hierarchy of model complexities. Agricultural and Forest Meteorology 148:1005-1020 Reference
Chen Q, Gong P, Baldocchi D, Tian YQ (2007) Estimating basal area and stem volume for individual trees from lidar data. Photogrammetric Engineering and Remote Sensing 73:1355-1365 Reference
Chen Q, Gong P, Baldocchi D, Xie G (2007) Filtering airborne laser scanning data with morphological methods. Photogrammetric Engineering and Remote Sensing 73:175-185 Reference
Chen XY, Rubin Y, Ma SY, Baldocchi D (2008) Observations and stochastic modeling of soil moisture control on evapotranspiration in a Californian oak savanna. Water Resources Research 44 Reference
Curiel Yuste J, Ma S, Baldocchi D (2010) Plant-soil interactions and acclimation to temperature of microbial-mediated soil respiration may affect predictions of soil CO2 efflux. Biogeochemistry Reference
D. D. Baldocchi; L. K. Xu; N. Kiang. 2004. How plant functional-type, weather, seasonal drought, and soil physical properties alter water and energy fluxes of an oak-grass savanna and an annual grasslandAgricultural and Forest Meteorology. 123:1-2, 13-39. Reference
Daniel A. Sims; Abdullah F. Rahman; Vicente D. Cordova; Dennis D. Baldocchi; Lawrence B. Flanagan; Allen H. Goldstein; David Y. Hollinger; Laurent Misson; Russell K. Monson; Hans P. Schmid. 2005. Midday values of gross CO2 flux and light use efficiency during satellite overpasses can be used to directly estimate eight-day mean fluxAgricultural and Forest Meteorology. 131:1-2, 1-12. Reference
Fisher JB, Baldocchi DD, Misson L, Dawson TE, Goldstein AH (2007) What the towers don't see at night: nocturnal sap flow in trees and shrubs at two AmeriFlux sites in California. Tree Physiology 27:597-610 Reference
Hibbard, et al. 2005. Biogeochemistry, 73, 29-70 Reference
J. Kim; Q. Guo; D.D. Baldocchi; M.Y. Leclerc; L. Xu; H.P. Schmid. 2006. Upscaling fluxes from tower to landscape: Overlaying flux footprints on high-resolution (IKONOS) images of vegetation coverAgricultural and Forest Meteorology. 136:3-4, 132-146. Reference
J. Tang; D. Baldocchi; Y. Qi; L. Xu. 2003. Assessing soil CO2 efflux using continuous measurements of CO2 profiles in soils with small solid-state sensorsAgricultural and Forest Meteorology. 118:3-4, 207-220. Reference
Jianwu Tang; Dennis D. Baldocchi. 2005. Spatial-temporal variation in soil respiration in an oak-grass savanna ecosystem in California and its partitioning into autotrophic and heterotrophic componentsBiogeochemistry. 73:1, 183-207. Reference
K. A. Hibbard; B. E. Law; M. Reichstein; J. Sulzman. 2005. An analysis of soil respiration across northern hemisphere temperate ecosystemsBiogeochemistry. 73:1, 29-70. Reference
Kobayashi, H., D. D. Baldocchi, Y. Ryu, Q. Chen, S. Ma, J. L. Osuna, and S. L. Ustin (2012), Modeling energy and carbon fluxes in a heterogeneous oak woodland: A three-dimensional approach, Agricultural and Forest Meteorology, 152, 83-100. Reference
L. H. Gu; E. M. Falge; T. Boden; D. D. Baldocchi; T. A. Black; S. R. Saleska; T. Suni; S. B. Verma; T. Vesala; S. C. Wofsy; L. K. Xu. 2005. Objective threshold determination for nighttime eddy flux filteringAgricultural and Forest Meteorology. 128:3-4, 179-197. Reference
L. K. Xu; D. D. Baldocchi. 2003. Seasonal trends in photosynthetic parameters and stomatal conductance of blue oak (Quercus douglasii) under prolonged summer drought and high temperatureTree Physiology. 23:13, 865-877. Reference
L. Xu; D.D. Baldocchi; J. Tang. 2004. How soil moisture, rain pulses, and growth alter the response of ecosystem respiration to temperatureGlobal Biogeochemical Cycles. 18:4, GB4002 10.1029/2004GB002281. Reference
Ma, S., Baldocchi, D.D., Xu, L., & Hehn, T. (2007). Inter-annual variability in carbon dioxide exchange of an oak/grass savanna and open grassland in California. Agricultural and Forest Meteorology, 147, 157-171 Primary_Citation
Ma, S., D. D. Baldocchi, S. Mambelli, and T. E. Dawson (2011), Are temporal variations of leaf traits responsible for seasonal and inter-annual variability in ecosystem CO2 exchange?, Functional Ecology, 25(1), 258-270. Reference
Miller, G. R., X. Chen, Y. Rubin, S. Ma, and D. D. Baldocchi (2010), Groundwater uptake by woody vegetation in a semiarid oak savanna, Water Resour. Res., 46(10), Reference
Raz-Yaseef, N., L. Koteen, and D. D. Baldocchi (2013), Coarse root distribution of a semi-arid oak savanna estimated with ground penetrating radar, Journal of Geophysical Research: Biogeosciences Reference
Ryu Y, Nilson T, Kobayashi H, Sonnentag O, Law BE, Baldocchi DD (2010) On the correct estimation of effective leaf area index: Does it reveal information on clumping effects? Agricultural and Forest Meteorology 150:463-472 Reference
Ryu Y, Sonnentag O, Nilson T, Vargas R, Kobayashi H, Wenk R, Baldocchi DD (2010) How to quantify tree leaf area index in an open savanna ecosystem: A multi-instrument and multi-model approach. Agricultural and Forest Meteorology 150:63-76 Reference
Xu, L. and Baldocchi, D., 2003. Seasonal trends in photosynthetic parameters and stomatal conductance of blue oak (Quercus douglasii) under prolaonged summer drought and high temperature. Tree Physiology, 23: 865-877. Reference

These pages show the current information available at http://ameriflux.lbl.gov about this tower.
**Site Team Only** If any of this information is wrong or missing, please submit corrections and updates via http://ameriflux.lbl.gov/web-submit-ui/?site_id=US-Ton