Modeling of the geochemical carbon cycle and its effect on atmospheric CO2 over Phanerozoic time (Berner, 1990;1991) has revealed the importance of knowing more about how land plants affect chemical weathering. This includes the effect of plants on the rate of uptake of CO2 by silicate and the feedback response of weathering, with and without plants, to changes in CO2. This project will investigate the role of plants in weathering by a field study on the island of Hawaii. Hawaii offers a unique opportunity to study weathering because here there are: (1) dated basalts ranging back to more that 4000 years (2) a wide range of plant life, from lichens and algae to well developed rainforest, within small regions of constant bedrock lithology and constant microclimate and (3) access to the expertise of biologists who are presently studying plant ecology in the same area. We plan to measure the thickness and mineralogical and chemical composition of weathering rinds and soils on flows with an eye to comparing relative rates of weathering in the presence and absence of specific biota. Results of this work, when combined with results from planned future studies of the effects of specific plants grown at varying CO2 levels on weathering rate, will be employed on our carbon cycle model to place some limits on how atmospheric CO2 might have changed as a result of the rise of vascular plants over geologic time

Agency
National Science Foundation (NSF)
Institute
Division of Earth Sciences (EAR)
Type
Standard Grant (Standard)
Application #
9117099
Program Officer
John A. Maccini
Project Start
Project End
Budget Start
1992-01-15
Budget End
1994-12-31
Support Year
Fiscal Year
1991
Total Cost
$179,896
Indirect Cost
Name
Yale University
Department
Type
DUNS #
City
New Haven
State
CT
Country
United States
Zip Code
06520