Research Projects

(1)  Dynamics of C in vegetation and soils of Amazon forests
NASA LBA ECO team CD08 includes Trumbore at UCI, Plinio Camargo, Luiz Martinelli and Simone Vieira at CENA (Univ. Sao Paulo), Niro Higuchi and Joaquim dos Santos at INPA (Manaus), Jeff Chambers at Tulane, and Foster Brown and Diogo Selhorst at SETEM, Univ. Federal do Acre (Rio Branco). 

Recent publications:

Vieira, S,  SE Trumbore,  P Camargo, D Selhorst, JQ Chambers, N Higuchi, and LA Martinelli, Slow growth rates of Amazonian trees: consequences for carbon cycling. Proc. Nat. Acad. Sci. 102 (51), 2005
Link

Trumbore S, E Salazar da Costa, DC Nepstad, PB Camargo, LA Martinelli, D Ray, T Restom, W Silver. Dynamics of fine root carbon in Amazonian tropical ecosystems and the contribution of roots to soil respiration. Global Change Biology, CaRTE Thematic Section, in press.

Vieira S. de Camargo PB. Selhorst D. da Silva R. Hutyra L. Chambers JQ. Brown IF. Higuchi N. dos Santos J. Wofsy SC. Trumbore SE. Martinelli LA. Forest structure and carbon dynamics in Amazonian tropical rain forests.  Oecologia. 140(3):468-479, 2004.     link

Chambers, J Q, N Higuchi, L M Teixeira, J dos Santos, S G Laurance and S E Trumbore, Response of tree biomass and wood litter to disturbance in a Central Amazon forest, Oecologia 141:596-611, DOI: 10.1007/s00442-004-1676-2 , 2004.  link

Telles, E., P. Camargo, L. M. Martinelli, S. E. Trumbore, E. Salazar da Costa, J. dos Santos, N. Higuchi, R. Cosme Oliveira, Influence of Soil Texture on Carbon Dynamics and Storage Potential in Tropical Forest Soils of Amazônia, Global Biogeochemical Cycles  (2003)  pdf

More information on CD-08 accomplishments, including other publications  here
Data sets: see LBA DIS holdings here
simone and sue



(2)  Soil respiration - NSF project with Claudia Czimczik, Ted Schuur, James T Randerson, and Eric A Davidson

partitioning in boreal forest
 We are using radiocarbon in combination with automated chamber systems to partition sources of soil respiration into plant and microbial components using a combination of field measurements of soil respiration and incubations of roots, litter and soil.  The UCI portion of this study includes studeis of:

- how the sources of soil respiration change with time since fire on a chronosequence in boreal forest in central Manitoba (former BOREAS sites).  See also Mike Goulden's web site for more information.

- how N amendment affects turnover of roots and partitioning of soil respiration in forests and tundra (PhD thesis of Nicole Nowinski)

- Extrapolation of radiocarbon isodisequilibrium to the global scale through monitoring of 14C at Point Barrow, Alaska and along a transect crossing the equator (with Xiaomei Xu, Nir Krakauer, Stan Tyler and Henry Agie).

See forthcoming papers in the February 2006 issue of Global Change Biology!


(3)  A whole ecosystem 14C label in Oak Ridge Tennessee (the EBIS project)
In July-August of 1999, Julia Gaudinski detected a large 14C release while sampling at the Oak Ridge Reserve in Tennessee.  With EBIS co-investigators Paul Hanson (ORNL), Julie Jastrow (ANL), Margaret Torn (LBL) and Chris Swanston (LLNL) we are following the label through leaf and root litter into soil organic matter pools.  The UCI portion, which made up the PhD thesis of Luz Maria Cisneros Dozal (12/05), used the lable to partition the sources of soil respiration.

Link to the EBIS web site
EOS article (Trumbore et al. 1992)
Cisneros Dozal et al. 2005 (part of the CaRTE thematic section in Global Change Biology)


Photo:  Tarps to collect labeled litter at the EBIS field sites
 Tarps deployed to catch labeled leaf litter

(4)  Low-level 14C labeling in the field

Labeling Dome near Bishop CA The high sensitivity of AMS allows us to detect very low levels of additional radiocarbon - for example, a doubling of natural radiocarbon levels is a large signal.  We are developing field based methods to exploit this that test hypotheses about the residence time and fate of C fixed by mature woody plants.


Locations:   UCI Marsh (Czimczik et al. 2005)
                   Manitoba, Canada (Carbone et al., submitted)
                   Near Delta, Alaska (with Kathleen Treseder)
                   Near Bishop, CA (Ph.D. thesis of Mariah Carbone)


(photo from grassland site in the Owens Valley, CA)