Carbon cycling and gas exchange in soils
This thesis summaries three independent projects, each of which describes a method which can be used to study the role of soils in regulating the atmospheric concentrations of CO{sub 2} and other trace gases. The first chapter uses the distribution of natural and bomb produced radiocarbon in fractionated soil organic matter to quantify the turnover of carbon in soils. A comparison of {sup 137}Cs and {sup 14}C in the modern soil profiles indicates that carbon is transported vertically in the soil as dissolved organic material. The remainder of the work reported is concerned with the use of inert trace gases to explore the physical factors which control the seasonal to diel variability in the fluxes of CO{sub 2} and other trace gases from soils. Chapter 2 introduces a method for measuring soil gas exchange rates in situ using sulfur hexafluoride as a purposeful tracer. The measurement method uses standard flux box technology, and includes simultaneous determination of the fluxes and soil atmosphere concentrations of CO{sub 2} and CH{sub 4}. In Chapter 3, the natural tracer {sup 222}Rn is used as an inert analog for exchange both in the soils and forest canopy of the Amazon rain forest.
- Research Organization:
- Columbia Univ., New York, NY (USA)
- OSTI ID:
- 6747658
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Storage and turnover of organic matter in soil
Gas exchange measurements in natural systems
Related Subjects
SOILS
CARBON CYCLE
AMAZON RIVER
CANOPIES
CARBON 14
CARBON DIOXIDE
CESIUM 147
DAILY VARIATIONS
FORESTS
GAS FLOW
METHANE
RADON 222
SEASONAL VARIATIONS
SOIL CHEMISTRY
ALKALI METAL ISOTOPES
ALKANES
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON OXIDES
CESIUM ISOTOPES
CHALCOGENIDES
CHEMISTRY
DAYS LIVING RADIOISOTOPES
EVEN-EVEN NUCLEI
FLUID FLOW
HEAVY NUCLEI
HYDROCARBONS
ISOTOPES
LIGHT NUCLEI
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RADIOISOTOPES
RADON ISOTOPES
RIVERS
STREAMS
SURFACE WATERS
VARIATIONS
YEARS LIVING RADIOISOTOPES
540230* - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- (1990-)
540220 - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)