PB 103 The six chapters (Chapters 10-15) in Part III consider the current and future carbon balance of terrestrial and aquatic ecosystems in North America. Although the amount of carbon exchanged between these ecosystems and the atmosphere each year through photosynthesis and plant and microbial respiration is large, the net balance for all of the ecosystems combined is currently a net sink of ...

-Aerosol elemental carbon measurements were taken at two rural sites in southwestern Pennsylvania during August 1983. Carbon, though a small part of the aerosol mass at both sites, was a leading constituent of the aerosol on an atom basis. Time-weighted average concentrations at Allegheny Mountain and Laurel Hill were 1.2 and 1.4 #g m-3, respectively. Absolute Principal Component Analysis follo...

The concept of source and sink strength is presently well-recognized and accepted by the scientific community as a pertinent approach describing the mechanisms of carbohydrate partitioning into the different and competing organs at a whole plant or canopy scales. Sink–source relationships have a clear role in the size of sink organs. Besides the effect on organ size, sink/source ratio might also...

Approximately 75–80% of the population of North America currently lives in urban areas as defined by national census bureaus, and urbanization is continuing to increase. Future trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if the activities of urban residents and the rate of urban land conversion can be captured in urban systems models, plausib...

Approximately 75–80% of the population of North America currently lives in urban areas as defined by national census bureaus, and urbanization is continuing to increase. Future trajectories of fossil fuel emissions are associated with a high degree of uncertainty; however, if the activities of urban residents and the rate of urban land conversion can be captured in urban systems models, plausib...

Climate warming affects permafrost soil carbon pools in two opposing ways: enhanced vegetation growth leads to higher carbon inputs to the soil, whereas permafrost melting accelerates decomposition and hence carbon release. Here, we study the spatial and temporal dynamics of these two processes under scenarios of climate change and evaluate their influence on the carbon balance of the permafros...