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S B McLaughlin

Publications and source records attributed to S B McLaughlin.

9 recordsLinked to original sources
PubMed2002

High-value renewable energy from prairie grasses.

Projected economic benefits of renewable energy derived from a native prairie grass, switchgrass, include nonmarket values that can reduce net fuel costs to near zero. At a farm gate price of $44.00/dry Mg, an agricultural sector model predicts higher profits for switchgrass than conventional crops on 16.9 million hectares (ha). Benefits would include an annual increase of $6 billion in net farm returns, a $1.86 billion reduction in government subsidies, and displacement of 44-159 Tg/year (1 Tg = 1012 g) of greenhouse gas emissions. Incorporating these values into the pricing structure for switchgrass bioenergy could accelerate commercialization and provide net benefits to the U.S. economy.

Bioelectric Energy Sources↗
PubMed1991

Seasonal changes in shoot water relations of Picea rubens at two high elevation sites in the Smoky Mountains.

Seasonal changes in water relations of current-year shoots of red spruce (Picea rubens Sarg.) were examined in relation to climatic conditions in trees growing at elevations of 1720 and 1935 m on Clingman's Dome, Tennessee, USA, where increment core data have shown that red spruce decline increases with elevation. Relative height growth of trees at 1720 m was 68% greater than in trees at 1935 m. Following two weeks in July with only traces of precipitation, trees at both sites showed decreased saturated osmotic potentials. The magnitude of the reduction was greater in trees at the high elevation site than in trees at the low elevation site. However, during August and September, shoot water relations of trees at both sites were similar. Precipitation patterns and water relations measurements suggested that, at both sites, trees experienced water stress only briefly during the growing season and to a degree that could not account for the lower growth rates of trees at the high elevation site. During the period of cold hardening in October and November, trees at the low elevation site exhibited saturated osmotic potentials that were lower by 0.2 MPa and solute accumulation (osmol kg(dw) (-1)) that was 48% greater than in trees at the high elevation site.

Journal Article↗
PubMed1983

Effects of SO(2) and O(3) on Allocation of C-Labeled Photosynthate in Phaseolus vulgaris.

A series of laboratory exposures of two varieties of bush bean (Phaseolus vulgaris L., var 274 and var 290) was conducted to determine the sensitivity of [(14)C]photosynthate allocation patterns to alteration by SO(2) and O(3). Experiments with the pollution-resistant 274 variety demonstrated short-term changes in both (14)C and biomass allocation to roots of (14)CO(2)-labeled plants but no significant effect on yield by up to 40 hours of exposure to SO(2) at 0.50 microliters per liter or 4 hours of O(3) at 0.40 microliters per liter. Subsequent experiments with the more sensitive 290 variety demonstrated significant alteration of photosynthesis, translocation, and partitioning of photosynthate between plant parts including developing pods. Significant increases in foliar retention of photosynthate (+40%) occurred after 8 hours of exposure to SO(2) at 0.75 microliters per liter (6.0 microliters per liter-hour) and 11 hours of exposure to O(3) at 0.30 microliters per liter-hour (3.3 microliters-hours). Time series sampling of labeled tissues after (14)CO(2) uptake showed that the disruption of translocation patterns was persistent for at least 1 week after exposures ceased. Subsequent longer-term exposures at lower concentrations of both O(3) (0.0, 0.10, 0.15, and 0.20 microliters per liter) and SO(2) (0.0, 0.20, and 0.40 microliters per liter) demonstrated that O(3) more effectively altered allocation than SO(2), that primary leaves were generally more sensitive than trifoliates, and that responses of trifoliate leaves varied with plant growth stage. Altered rates of allocation of photosynthate by leaves were generally associated with alterations of similar magnitude and opposite direction in developing pods. Collectively, these experiments suggest that allocation patterns can provide sensitive indices of incipient growth responses of pollution-stressed vegetation.

Journal Article↗