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Full-Text Articles in Physical Sciences and Mathematics
Influence Of Natural And Novel Organic Carbon Sources On Denitrification In Forest, Degraded Urban, And Restored Streams, Ta Newcomer, Ss Kaushal, Pm Mayer, Ar Shields, Elizabeth A. Canuel, Et Al
Influence Of Natural And Novel Organic Carbon Sources On Denitrification In Forest, Degraded Urban, And Restored Streams, Ta Newcomer, Ss Kaushal, Pm Mayer, Ar Shields, Elizabeth A. Canuel, Et Al
VIMS Articles
Organic carbon is important in regulating ecosystem function, and its source and abundance may be altered by urbanization. We investigated shifts in organic carbon quantity and quality associated with urbanization and ecosystem restoration, and its potential effects on denitrification at the riparian-stream interface. Field measurements of streamwater chemistry, organic carbon characterization, and laboratory-based denitrification experiments were completed at two forested, two restored, and two unrestored urban streams at the Baltimore Long-Term Ecological Research site, Maryland, USA. Dissolved organic carbon (DOC) and nitrate loads increased with runoff according to a power-law function that varied across sites. Stable isotopes and molar C:N …
Impact Of Diatom-Diazotroph Associations On Carbon Export In The Amazon River Plume, Ly Yeung, Wm Berelsen, Et Al, Deborah K. Steinberg, Et Al
Impact Of Diatom-Diazotroph Associations On Carbon Export In The Amazon River Plume, Ly Yeung, Wm Berelsen, Et Al, Deborah K. Steinberg, Et Al
VIMS Articles
Offshore tropical river plumes are associated with areas of high N-2 fixation (diazotrophy) and biological carbon drawdown. Episodic blooms of the diatom Hemiaulus hauckii and its diazotrophic cyanobacterial symbiont Richelia intracellularis are believed to dominate that carbon drawdown, but the mechanism is not well understood. We report primary productivity associated with blooms of these diatom-diazotroph assemblages (DDAs) in the offshore plume of the Amazon River using simultaneous measurements of O-2/Ar ratios and the triple-isotope composition of dissolved O-2. In these blooms, we observe peaks in net community productivity, but relatively small changes in gross primary productivity, suggesting that DDA blooms …
Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, D G. Martinson, D P. Costa
Two Decades Of Pelagic Ecology Of The Western Antarctic Peninsula, Deborah K. Steinberg, D G. Martinson, D P. Costa
VIMS Articles
Significant strides in our understanding of the marine pelagic ecosystem of the Western Antarctic Peninsula (WAP) region have been made over the past two decades, resulting from research conducted aboard ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer. These advances range from an understanding of the physical forcing on biology, to food web ecology (from microbes to top predators), to biogeochemical cycling, often in the larger context of rapid climate warming in the region. The proximity of the WAP to the Antarctic Circumpolar Current and WAP continental shelf bathymetry affects the hydrography and helps structure the biological community. Seasonal, …