Doctor of Natural Sciences, Swiss Federal Institute
of Technology (ETH-Zürich), 2000
M.S. Syracuse University, 1995
B.A. University of Kansas, 1992
Office: PC 342B
Laboratory: QSL PC 305, SIL OE 310
Telephone: (305) 348-2693/7475/3044
Isotope Biogeochemsitry and Paleoclimatology
My current research focuses on the oxygen, carbon,
and nitrogen isotopic signature in organic material.
This work/approach is focused on the calibration
and reconstruction of the isotopic hydrologic
cycle from terrestrial archives (tree rings
and lake sediments) located in the US, Europe,
and South America. Present work focuses on applying
new continuous flow isotope ratio mass spectrometry
(CF-IRMS) methods to biogeocemical orientated
projects in the Everglades, The Keys, Florida
Bay, and other tropical locations in South America.
The goal of this approach is to better understand
how changes in the hydrologic cycle and environmental
conditions (nutrients, pCO2, stress, etc.) affect
different biogeochemical systems, which aids
in improving our understanding of past and present
SERC Stable Isotope Laboratory (http://www.fiu.edu/~sil)
is equipped with three mass spectrometers including:
a Finnigan deltaC EA-IRMS, a Finnigan deltaPlus
GC-IRMS, and a Micromass Prism with both duel
inlet and continuous flow EA modes. The laboratory
can measure all important stable isotopes (C,N,S,
and O), in a variety of inorganic and organic
Current research projects include:
Florida Marine Stable Isotope Time Series
Understanding nitrogen and carbon isotopic signals
from organic matter in modern systems with implications
for geologic records (funded by ACS PRF-38095-G2).
Samantha Evans (Doctoral Student) has just completed
her first year of quarterly POM sampling at
6 stations in the Florida Keys National Marine
Sanctuary and Florida Bay. This work is being
done in conjunction with the Seagrass Lab (directly
by James Fourqurean) and the FCE-LTER.
History of Florida Bay, Everglades National
FIU geologists, biologists and chemists are
investigating the amount of variation in coastal
environmental conditions that is naturally occurring.
Our approach is to reconstruct the historical
record of seagrass abundance, which is highly
correlated with environmental water quality.
We have collected sediment cores and obtained
ages as old as 4000+ years, and we are using
proxies of seagrass abundance contained in the
sediment as indicators of the environmental
water quality of the past few hundred years.
I am studying seagrass-associated foraminifera
as an indicator of seagrass abundance, and will
combine my results with the other proxies (sedimentology,
geochemistry, diatoms) to produce an integrated
history of Florida Bay seagrass abundance.
signals in Tropical and semi-Tropical tree
Our recent work in Brazil and South Florida
have shown it is possible to two work with and
find ring forming species in low latitude areas
with strong seasonal wet/dry periods. We are
now working on water-level reconstructions in
wetlands systems using stable isotopes. This
work is being done in conjunction with the Leo
Sternberg at the University of Miami.
- The geologic study of lakes as archives of
Recently the group has started to focus on Quaternary
Research with the opening of the Quaternary
Science Laboratory, which is equiped several
lake core systems and sample modern sample processing
systems. In the past we have work with groups
at Syracuse on Lake Ontario and with Matt Kirby
at CalState Fullerton on Lake Elsinore. Presently
we have two funded projects studying paleoclimate
and paleoecological archives in lakes and peat
bogs: 1) Sediment nutrient characteristics and
paleolimnological reconstruction of Lake Monroe,
Florida, USA, (with Gaiser and Scinto, both
at FIU), funded by the St. John's River Water
Management District; and 2) Lynch's Crater,
Queensland: A terrestrial climate record of
the past 200,000 years as a key to understand
modern climatic fluctuations, with Wust and
Kershaw (both at James Cook Uni., Australia),
funded by Australian Research Council.
J.R., Childers, D.L., Anderson, W.T.,
Rudnick, D.T., and Madden, C.J., 2008, An in
situ mesocosm method for quantifying nitrogen
cycling rates in oligotrophic wetlands using
15N tracer techniques: Wetlands, v. 28,
n. 2, p. 502-512.
J., Kylander, M., Wüst, R.A.J., Weiss,
D., Martinez-Cortizas, A., LeGrande, A. N.,
Jennerjahn, T., Behling, H., Anderson, W.T.,
Jacobson, G, 2008, Possible evidence for wet
Heinrich phases in tropical NE Australia: The
Lynchs Crater deposit: Quaternary Science
Reviews, v. 27, p. 468-475.
L.S.L., Pinzon, M.C., Vendramini, P., Anderson,
W.T., Jahren, H., and Beuning, K., 2007,
Oxygen isotope ratios of cellulose-derived phenylglucosazone:
An improved paleoclimate indicator of environmental
water and relative humidity: Geochimica et
Cosmochimica Acta, v. 71, p. 2463-2473.
L, Pinzon, M.C., Anderson, W.T., and
Jahren, A.H., 2006, Variation in oxygen isotope
fractionation during cellulose synthesis: Molecular
and biosynthetic effects: Plant, Cell and
Environment. v. 29, p. 1881-1889.
S.L., Anderson, W.T., and Jochem, F.J.,
2006, Spatial variability in Florida Bay particulate
organic matter composition: combining flow cytometry
with stable isotope analyses: Hydrobiologia,
v. 569, p. 151-165.
J.W., Escoria, S.P., Anderson, W.T.,
and Zieman, J., 2005, Spatial and seasonal variability
in elemental content, d13C and d15N of Thalassia
testudinum from south Florida and its implications
for ecosystem studies: Estuaries, v.
28, n. 3, p. 447-461.
W.T., Sternberg, L., Pinzon, M.C., Gann-Troxler,
T., Childers, D.L., and Duever, M., 2005, Carbon
isotope composition of cypress trees from South
Florida and changing hydrologic conditions:
Dendrochronologia, v. 23, n. 1, p. 1-10.