Decomposition and nitrogen dynamics of 15N‑labeled leaf, root, and twig litter in temperate coniferous forests" (2013). USDA Forest Service / UNL Faculty Publications. Paper 253. patterns were species-specific. For multiple litter × species combinations, the difference between gross and net n mineralization was significant, and gross mineralization was 7–20 % greater than net mineralization. th...

Land-use change is likely to be a major component of global change at high latitudes, potentially causing significant alterations in soil C and N cycling. We addressed the biogeochemical impacts of land-use change in fully replicated black spruce forests and agricultural fields of different ages (following deforestation) and under different management regimes in interior Alaska. Change from for...

Carbon mineralization processes and their dependence on environmental conditions (e.g. through macrobenthic bioturbation) have been widely studied in temperate coastal sediments, but almost nothing is known about these processes in subtropical coastal sediments. This study investigated pathways of organic carbon mineralization and associated effects of macrobenthic bioturbation in winter and su...

Composting has emerged as a valuable route for the disposal of urban waste, with the prospect of applying composts on arable fields as organic amendments. Proper management of urban waste composts (UWCs) requires a capacity to predict their effects on carbon and nitrogen dynamics in the field, an issue in which simulation models are expected to play a prominent role. However, the parameterizati...

Large changes in atmospheric CO2, temperature, and precipitation are predicted by 2100, yet the long-term consequences for carbon (C), water, and nitrogen (N) cycling in forests are poorly understood. We applied the PnET-CN ecosystem model to compare the long-term effects of changing climate and atmospheric CO2 on productivity, evapotranspiration, runoff, and net nitrogen mineralization in curr...

Plant-derived carbon compounds enter soils in a number of forms; two of the most abundant being leaf litter and rhizodeposition. Our knowledge concerning the predominant controls on the cycling of leaf litter far outweighs that for rhizodeposition even though the constituents of rhizodeposits includes a cocktail of low molecular weight organic compounds which represent a rapidly cycling source ...

Benthic chambers were used to measure in situ fluxes of dissolved gases (N2, O2, and N2O) and inorganic nutrients (NO3 , NH4 , and PO4 3 ) in continental shelf sediments of the Mid-Atlantic Bight during spring through autumn (May– November). Denitrification was determined by the rate of increase in N2 relative to Ar, measured using membrane-inlet mass spectrometry. Although sediments were a sou...

2.1 NITROGEN AND IT ROLE IN THE PLANT.................................................................................... 3 2.2 THE PLANT NITROGEN STATUS ................................................................................................ 4 2.3 PLANT AVAILABLE NITROGEN ................................................................................................. 5 2.3.1 Root inte...