| U.S.
JGOFS
Synthesis & Modeling Project |
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| Edward A. Laws | ||
| An f-ratio model for
pelagic marine ecosystems
NSF: OCE-9725966, 36 months |
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| PROJECT DESCRIPTION: | The proposed research will be the development of
a simple ecosystem model which will account for observed f-ratios in pelagic
marine ecosystems during both steady state and non-steady state conditions.
The central hypotheses of the model are as follows: ( 1) Production is
controlled by a single nutrient, the identity of which is determined by
the nutritional requirements of the phytoplankton community and the ratio
of allochthonous nutrient inputs to the system. (2) The size spectrum
of the phytoplankton community is a critical determinant of the f-ratio.
Large cells are associated with a high f-ratio, and small cells are associated
with a low f-ratio. (3) Marine pelagic ecosystems naturally evolve
toward a condition in which stability is maximized. Work carried
out to date indicates that maximum stability is associated with low f-ratios,
i.e., in the range 0.05-0.1. Nutrient pulses are expected to shift
the f-ratio to larger values because under steady-state conditions the
large-celled phytoplankton are always growing at a low relative growth
rate, and the small-celled phytoplankton are growing at a high relative
growth rate. The principal long-term goal of the proposed research
is the development of a simple model of the f-ratio which can be embedded
into much larger ocean/atmosphere models to explain the production and
export of organic carbon from the euphotic zone. A secondary
goal of the proposed work will be the development of a theoretical framework
with which to reconcile various measures of the productivity and turnover
of pelagic marine ecosystems, i.e., differences between gross photosynthesis
and net photosynthetic production of particulate carbon.
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| DATA: |
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| PUBLICATIONS: | See the Publications section of the continuation project "Development of an adaptive
food web model to explain carbon cycling in the ocean"
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| RELATED PROJECTS: | Laws, Caldeira, Milovich "Development of an adaptive
food web model to explain carbon cycling in the ocean"
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| INVESTIGATOR
INFORMATION: |
Edward A. Laws
Department of Oceanography 1000 Pope Road Marine Science Building University of Hawaii Honolulu, HI 96822 tel: (808) 956-7402, 8952 fax: (808) 956-9225 laws@soest.hawaii.edu http://www.soest.hawaii.edu/oceanography/faculty_html/laws.html |