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Full-Text Articles in Botany
Differential Hydrogen Isotopic Ratios Of Sphagnum And Vascular Plant Biomarkers In Ombrotrophic Peatlands As A Quantitative Proxy For Precipitation-Evaporation Balance, J. Nichols, R. K. Booth, Stephen T. Jackson, Elise Pendall, Y. S. Huang
Differential Hydrogen Isotopic Ratios Of Sphagnum And Vascular Plant Biomarkers In Ombrotrophic Peatlands As A Quantitative Proxy For Precipitation-Evaporation Balance, J. Nichols, R. K. Booth, Stephen T. Jackson, Elise Pendall, Y. S. Huang
Elise Pendall
We have developed a new approach to quantitatively reconstruct past changes in evaporation based on compound-specific hydrogen isotope ratios of vascular plant and Sphagnum biomarkers in ombrotrophic peatland sediments. We show that the contrast in H isotopic ratios of water available to living Sphagnum (top 20 cm) and in the rooting zone of peatland vascular plants can be used to estimate "f"-the fraction of water remaining after evaporation. Vascular plant leaf waxes record H isotopic ratios of acrotelm water, which carries the D/H ratio signature of precipitation and is little affected by evaporation, whereas the Sphagnum biomarker, C23 n-alkane, records …
Elevated Atmospheric Co2 Effects And Soil Water Feedbacks On Soil Respiration Components In A Colorado Grassland, Elise Pendall, S. Del Grosso, J. Y. King, D. R. Lecain, D. G. Milchunas, J. A. Morgan, A. R. Mosier, D. S. Ojima, W. A. Parton, P. P. Tans, J.W.C. White
Elevated Atmospheric Co2 Effects And Soil Water Feedbacks On Soil Respiration Components In A Colorado Grassland, Elise Pendall, S. Del Grosso, J. Y. King, D. R. Lecain, D. G. Milchunas, J. A. Morgan, A. R. Mosier, D. S. Ojima, W. A. Parton, P. P. Tans, J.W.C. White
Elise Pendall
The shortgrass steppe is a semi-arid grassland, where elevated CO2 reduces stomatal conductance and promotes soil moisture storage. Enhanced biomass growth from elevated CO2 has been attributed in part to soil moisture effects. However, the influence of this soil moisture feedback on C cycling has received little attention. We used open-top chambers to increase atmospheric CO2 concentrations to twice-ambient for four growing seasons. Soil respiration rates and stable C isotopes of soil CO2 were measured during the third and fourth seasons. Elevated CO2 increased soil respiration rates by similar to 25% in a moist growing season and by similar to …