Persistence of /sup 14/C labeled carbon in Larrea tridentata up to 40 months after photosynthetic fixation in the northern Mojave Desert
Larrea tridentata (Sesse Moc. ex DC) Cov. exposed to /sup 14/CO/sub 2/ retained about 20 percent of its /sup 14/C after 16 and also after 26 months. In leaves, however, a lower specific activity was present at 26 months than at 16 months, and a smaller percentage of /sup 14/C in the plant occurred in leaves at 26 months than at 26 months (3 percent vs 10 percent). This indicates some, but little, reuse of carbon from the structural components of the plants. The strong tendency of the species to retain this carbon may be related to a survival mechanism. After 40 months the results were more erratic, with 11 percent of /sup 14/C remaining in plants and only 2 percent of the total remaining in the leaves. The specific activity of /sup 14/C in the organic debris fraction obtained with saturated salt flotation of roots after small and fine roots had been physically removed indicated that from 27 to 35 percent of the organic debris had the same specific activity as roots and probably could be considered as roots. This compares with the 45 percent value determined previously by a different technique. The below-ground to aboveground ratio for biomass of these plants was about 2.5:1. The below-ground to above-ground ratio for the /sup 14/C was about 0.5 at 16 months, 1.3 at 26 months, and 2.5 at 40 months. The estimates obtained in this study were used to correct our previous data for below-ground biomass. Accordingly,somewhere between 3000 and 5000 kg/ha roots are present in the Rock Valley area. An increase wth time of the below-ground to aboveground /sup 14/C ratio probably indicates loss of /sup 14/C from above-ground parts rather than additional transport to roots.
- Research Organization:
- Univ. of California, Los Angeles
- OSTI ID:
- 6594537
- Journal Information:
- Great Basin Nat.; (United States), Vol. 4
- Country of Publication:
- United States
- Language:
- English
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Distribution of photosynthetically fixed /sup 14/C in perennial plant species of the northern Mojave Desert
Field studies of mineral nutrition of Larrea tridentata: importance of N, pH, and Fe
Related Subjects
54 ENVIRONMENTAL SCIENCES
CARBON 14
RETENTION
ROOTS
BIOMASS
SHRUBS
CARBON CYCLE
CARBON DIOXIDE
DESERTS
EXPERIMENTAL DATA
NEVADA
PLANT STEMS
TIME DEPENDENCE
ARID LANDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON OXIDES
CHALCOGENIDES
DATA
ENERGY SOURCES
EVEN-EVEN NUCLEI
INFORMATION
ISOTOPES
LIGHT NUCLEI
NORTH AMERICA
NUCLEI
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PLANTS
RADIOISOTOPES
RENEWABLE ENERGY SOURCES
USA
WESTERN REGION
YEARS LIVING RADIOISOTOPES
560173* - Radiation Effects- Nuclide Kinetics & Toxicology- Plants- (-1987)
510100 - Environment
Terrestrial- Basic Studies- (-1989)