| U.S.
JGOFS
Synthesis & Modeling Project |
||
|
Michael Lizotte
Giacomo DiTullio | ||
|
JGOFS synthesis: The role of phytoplankton community
structure in determining particulate elemental composition, carbon fixation,
and bio-optical properties
NSF ('99), 36 months |
 |
|
| PROJECT DESCRIPTION: |
Phytoplankton community structure and biogeography have been identified
as key gaps in the knowledge needed to progress from current ocean biogeochemistry
models (with generic phytoplankton parameterizations) to more explicit
models. In particular, deviations from generic phytoplankton descriptions
may be greatest during episodic blooms of a few species, and in some regions
these episodic events are associated with rapid flux of particulate carbon
to the seafloor, distinct biogeochemical processes (e.g., N-fixation, carbonate
precipitation, dimethylsulfide production), or shifts in elemental composition
of particulate matter. Thus, future biogeochemical models may need
to shift parameterizations to reflect biogeographic regions and/or seasonal
blooms. During the JGOFS era, High-Performance-Liquid-Chromatography
(HPLC) methods for characterizing phytoplankton pigments were used widely,
and these data sets can be used to make a first-order approximation of
phytoplankton community structure. We propose to analyze HPLC pigment data
sets collected worldwide to develop algorithms (on event,
regional, and
global scales) for estimating phytoplankton community structure.
Our estimates of phytoplankton community structure from HPLC pigments will
be compared to microscopy and flow-cytometry data, when available, to test
the validity of these new algorithms. We will use the compiled and
synthesized data sets to study biogeographical distributions of phytoplankton.
We will also extract subsets of the data for samples dominated by single
taxonomic groups (e.g., diatoms, coccolithophorids, picocyanobacteria,
Phaeocystis
spp.) to determine whether other phytoplankton-related parameters are correlated
with community structure. The ancillary data sets that we will compile
for phytoplankton-related parameters will be those most useful for developing
SMP biogeochemical models and for remote sensing of phytoplankton biomass
(e.g. particulate carbon, nitrogen, and absorbance; carbon:chlorophyll
a ratios; photosynthetic rates; photosynthesis-irradiance parameters and
quantum yields; nutrient utilization indices and ratios; light attenuation;
reflectance ratios; and water column stability).
| |
| DATA: | - no data submitted - | |
| PUBLICATIONS: | - no publications listed - | |
| RELATED PROJECTS: |
- no related projects listed -
| |
| INVESTIGATOR
INFORMATION: |
Michael Lizotte
Dept. of Biology University of Wisconsin Oshkosh 800 Algoma Blvd. Oshkosh, WI 54901 tel: 920-424-0848 lizotte@uwosh.edu Giacomo R. DiTullio
|