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Climate change predictions derived from coupled carbon-climate models are highly dependent on assumptions about feedbacks between the biosphere and atmosphere. One critical feedback occurs if C uptake by the biosphere increases in response to the fossil-fuel driven increase in atmospheric [CO(2)] ("CO(2) fertilization"), thereby slowing the rate of increase(More)
Increases in tree biomass may be an important sink for CO 2 as the atmospheric concentration continues to increase. Tree growth in temperate forests is often limited by the availability of soil nutrients. To assess whether soil nutrient limitation will constrain forest productivity under high atmospheric CO 2 , we studied the changes in forest litter(More)
The idea that the concentration of secondary metabolites in plant tissues is controlled by the availability of carbon and nitrogen in the environment has been termed the carbon±nutrient balance hypothesis (CNB). This hypothesis has been invoked both for prediction and for post hoc explanation of the results of hundreds of studies. Although it successfully(More)
Perennial grass biofuels may contribute to long-term carbon sequestration in soils, thereby providing a broad range of environmental benefits. To quantify those benefits, the carbon balance was investigated over three perennial grass biofuel crops – miscanthus (Miscanthus × giganteus), switchgrass (Panicum virgatum) and a mixture of native prairie plants –(More)
Leaf photosynthesis and carbohydrate dynamics of soybeans under FACE A. Rogers et al. ABSTRACT A lower than theoretically expected increase in leaf photo-synthesis with long-term elevation of carbon dioxide concentration ([CO 2 ]) is often attributed to limitations in the capacity of the plant to utilize the additional photosynthate, possibly resulting from(More)
[1] In two parallel but independent experiments, Free Air CO 2 Enrichment (FACE) technology was used to expose plots within contrasting evergreen loblolly pine (Pinus taeda L.) and deciduous sweetgum (Liquidambar styraciflua L.) forests to the level of CO 2 anticipated in 2050. Net primary production (NPP) and net ecosystem production (NEP) increased in(More)
Arthropods and pathogens damage leaves in natural ecosystems and may reduce photosynthesis at some distance away from directly injured tissue. We quantified the indirect effects of naturally occurring biotic damage on leaf-level photosystem II operating efficiency (Phi(PSII)) of 11 understory hardwood tree species using chlorophyll fluorescence and thermal(More)
The effect of different feeding behaviours of 1st and 4th instar Trichoplusia ni on photosynthesis of Arabidopsis thaliana var. Columbia was characterized using spatially resolved measurements of fluorescence and leaf temperature, as well as leaf gas exchange,. First instars made small holes with a large perimeter-to-area ratio and avoided veins, while 4th(More)
We measured the short-term direct and long-term indirect effects of elevated CO 2 on leaf dark respiration of loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraci-flua) in an intact forest ecosystem. Trees were exposed to ambient or ambient + 200 m m m m mol mol-1 atmospheric CO 2 using free-air carbon dioxide enrichment (FACE) technology. After(More)
[1] A sound understanding of the sustainability of terrestrial carbon (C) sequestration is critical for the success of any policies geared toward stabilizing atmospheric greenhouse concentrations. This includes the Kyoto Protocol and/or other greenhouse strategies implemented by individual countries. However, the sustainability of C sinks and pools has not(More)