Now showing items 1-10 of 25
Controls on Soil Organic Carbon and Nitrogen in Inner Mongolia, China: A Cross-Continental Comparison of Temperate Grasslands
Author(s):Evans, S. E.; Burke, Ingrid; Lauenroth, William K.; Evans, S. E.; Burke, Ingrid; Lauenroth, William K.
Most global ecosystem models assume that controls over soil organic matter are alike in climatically similar regions. In this study, we tested the generality of controls over soil organic carbon (SOC) and soil organic ...
Examination of Subfamilial Phylogeny in Bromeliaceae Using Comparative Sequencing of the Plastid Locus Ndhf
Author(s):Terry, R. G.; Brown, Gregory K.; Olmstead, R. G.; Terry, R. G.; Brown, Gregory K.; Olmstead, R. G.
Parsimony analysis of 31 sequences of the chloroplast locus ndhF was used to address questions of subfamilial phylogeny in Bromeliaceae. Results presented here are congruent with those from chloroplast DNA restriction site ...
Differential Hydrogen Isotopic Ratios of Sphagnum and Vascular Plant Biomarkers in Ombrotrophic Peatlands as a Quantitative Proxy for Precipitation-Evaporation Balance
Author(s):Nichols, J.; Booth, R. K.; Jackson, Stephen T.; Pendall, Elise; Huang, Y. S.; Nichols, J.; Booth, R. K.; Jackson, Stephen T.; Pendall, Elise; Huang, Y. S.
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. ...
Morphological Variation of Some Floral Features of the Subfamily Pitcairnioideae (Bromeliaceae) and Their Significance in Pollination Biology
Author(s):Varadarajan, G. S.; Brown, Gregory K.; Varadarajan, G. S.; Brown, Gregory K.
Scanning electron and light microscopy observations of wet-preserved flowers of Bromeliaceae subfamily Pitcaimioideae yield new information on the stigma, petal scales, and septal nectaries. Variations of the stigma types ...
Carbon and Oxygen Isotope Analysis of Leaf Biomass Reveals Contrasting Photosynthetic Responses to Elevated Co2 Near Geologic Vents in Yellowstone National Park
Author(s):Sharma, S.; Williams, David G.; Sharma, S.; Williams, David G.
In this study we explore the use of natural CO2 emissions in Yellowstone National Park (YNP) in Wyoming, USA to study responses of natural vegetation to elevated CO2 levels. Radiocarbon (14C) analysis of leaf biomass from ...
Cladistic Relationships of Aechmea (Bromeliaceae, Bromelioideae) and Allied Genera
Author(s):de Faria, A. P. G.; Wendt, T.; Brown, Gregory K.; de Faria, A. P. G.; Wendt, T.; Brown, Gregory K.
Aechmea (ca. 220 species) is the largest and most diverse genus in Bromelioideae (Bromeliaceae), and several dissimilar generic concepts and infrageneric classifications have been proposed, frequently involving other closely ...
Daily to Decadal Patterns of Precipitation, Humidity, and Photosynthetic Physiology Recorded in the Spines of the Columnar Cactus, Carnegiea Gigantea
Author(s):English, N. B.; Dettman, D. L.; Sandquist, D. R.; Williams, David G.; English, N. B.; Dettman, D. L.; Sandquist, D. R.; Williams, David G.
Isotopic analyses of cactus spines grown serially from the apex of long-lived columnar cactuses may be useful for climatological and ecological studies if time series can be reliably determined from spines. To characterize ...
Sap Flux-Upscaled Canopy Transpiration, Stomatal Conductance, and Water Use Efficiency in an Old Growth Forest in the Great Lakes Region of the United States
Author(s):Tang, J. W.; Bolstad, P. V.; Ewers, Brent E.; Desai, A. R.; Davis, K. J.; Carey, E. V.; Tang, J. W.; Bolstad, P. V.; Ewers, Brent E.; Desai, A. R.; Davis, K. J.; Carey, E. V.
Combining sap flux and eddy covariance measurements provides a means to study plant stomatal conductance and the relationship between transpiration and photosynthesis. We measured sap flux using Granier-type sensors in a ...
Sex-Specific Trade-Offs and Responses to Foliar Shade in the Gynodioecious Species Silene Vulgaris (Caryophyllaceae)
Author(s):Dykstra, A. B.; Brock, M. T.; Delph, L. F.; Weinig, Cynthia; Dykstra, A. B.; Brock, M. T.; Delph, L. F.; Weinig, Cynthia
Allocation trade-offs are predicted to affect evolutionary dynamics, including the evolution of sexual dimorphism. In gynodioecious species, where populations have both females and hermaphrodites, selection may result in ...
Rapid Hydrologic Shifts and Prolonged Droughts in Rocky Mountain Headwaters During the Holocene
Author(s):Shuman, B.; Pribyl, P.; Minckley, Thomas; Shinker, J. J.; Shuman, B.; Pribyl, P.; Minckley, Thomas; Shinker, J. J.
Rapid hydroclimatic shifts repeatedly generated centuries to millennia of extensive aridity across the headwaters of three of North America's largest river systems during the Holocene. Evidence of past lake-level changes ...