Energy and carbon balances in cheatgrass: an essay in autecology

Journal Article · Wed Jan 01 04:00:00 EST 1975 · Ecol. Monogr.; (United States)

DOI:https://doi.org/10.2307/1942412· OSTI ID:7107235

Hinds, W T

Biotic and abiotic pathways of incident energy are rarely considered together in comparable detail, so little is known about whether energy or carbon relations remain constant in contrasting energy environments. An experiment to determine the fates of energy and carbon in cheatgrass (Bromus tectorum L.) was carried out on steep (40/sup 0/) north- and south-facing slopes on a small earth mound, using many small lysimeters to emulate swards of cheatgrass. Meteorological conditions and energy fluxes that were measured included air and soil temperatures, relative humidity, wind speed, incoming and reflected shortwave radiation, net all-wave radiation, heat flux to the soil, and evaporation and transpiration separately. The fate of photosynthetically fixed carbon during spring growth (31 March to 31 May) was determined by separation of the plant tissues into mineral nutrients, ash, crude protein, crude fat, crude fiber, and nitrogen-free extract (NFE) (the proximate analysis scheme routinely used for feed analysis) for roots, shoots, and seeds separately. Root and seed production were both about 30 percent greater on the north exposure than on the south, but shoot production was not different. Heats of combustion (caloric content) differed between roots, shoots, and seeds, but not between exposures. Total production and total energy fixation were not statistically different on the two exposures, because the greater biomass and variability of the shoots overwhelmed the statistically significant differences in roots and seeds. Incident shortwave radiation was very much greater on the south exposure than on the north, so the south exposure was much less efficient in converting solar energy into chemical energy stored in plant tissues.

• Research Organization: Battelle Pacific Northwest Labs., Richland, WA
• OSTI ID: 7107235
• Journal Information: Ecol. Monogr.; (United States), Journal Name: Ecol. Monogr.; (United States) Vol. 45; ISSN ECMOA
• Country of Publication: United States
• Language: English

Related Subjects

510100* -- Environment
Terrestrial-- Basic Studies-- (-1989)
54 ENVIRONMENTAL SCIENCES
BIOMASS
CARBON
CHEMICAL REACTIONS
ECOLOGY
ELEMENTS
ENERGY BALANCE
ENERGY SOURCES
EVAPORATION
GRASS
HEAT FLOW
HUMIDITY
HYDROGEN COMPOUNDS
METEOROLOGY
MONITORING
NONMETALS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHOTOCHEMICAL REACTIONS
PHOTOSYNTHESIS
PLANTS
RADIATIONS
RENEWABLE ENERGY SOURCES
ROOTS
SEEDS
SOILS
SYNTHESIS
TEMPERATURE MONITORING
WATER
WIND