Carbon and nitrogen emission in agroecosystems of Eastern Siberia

Abstract. Carbon (C) and nitrogen (N) released from biomass burning have multiple effects on the Earth's biogeochemical cycle, climate change, and ecosystem. These effects depend on the relative abundances of C and N species emitted, which vary with fuel type and combustion conditions. This study systematically investigates the emission characteristics of biomass burning under different fuel moisture contents, through controlled burning experiments with biomass and soil samples collected from a typical alpine forest in North America. Fuel moisture in general lowers combustion efficiency, shortens flaming phase, and introduces prolonged smoldering before ignition. It increases emission factors of incompletely oxidized C and N species, such as carbon monoxide (CO) and ammonia (NH3). Substantial particulate carbon and nitrogen (up to 4 times C in CO and 75% of N in NH3) were also generated from high-moisture fuels, maily associated with the pre-flame smoldering. This smoldering process emits particles that are larger and contain lower elemental carbon fractions than soot agglomerates commonly observed in flaming smoke. Hydrogen (H)/C ratio and optical properties of particulate matter from the high-moisture fuels show their resemblance to plant cellulous and brown carbon, respectively. These findings have implications for modeling biomass burning emissions and impacts.

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HST-COS OBSERVATIONS OF HYDROGEN, HELIUM, CARBON, AND NITROGEN EMISSION FROM THE SN 1987A REVERSE SHOCK

The Astrophysical Journal ◽

10.1088/0004-637x/743/2/186 ◽

2011 ◽

Vol 743 (2) ◽

pp. 186 ◽

Cited By ~ 26

Author(s):

Kevin France ◽

Richard McCray ◽

Steven V. Penton ◽

Robert P. Kirshner ◽

Peter Challis ◽

...

Keyword(s):

Reverse Shock ◽

Carbon And Nitrogen ◽

Sn 1987A ◽

Nitrogen Emission

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Metabolic signalling and the partitioning of resources in plant storage organs

The Journal of Agricultural Science ◽

10.1017/s0021859699006978 ◽

1999 ◽

Vol 133 (3) ◽

pp. 243-249 ◽

Cited By ~ 3

Author(s):

NIGEL G. HALFORD

Keyword(s):

Dry Weight ◽

Wild Relatives ◽

Crop Plants ◽

Wild Plants ◽

Young Plant ◽

Carbon And Nitrogen ◽

Cultivated Potato ◽

Metabolic Signalling ◽

Storage Organs ◽

Plant Storage

The most important harvested organs of crop plants, such as seeds, tubers and fruits, are often described as assimilate sinks. They play little or no part in the fixation of carbon through the production of sugars through photosynthesis, or in the uptake of nitrogen and sulphur, but import these assimilated resources to support metabolism and to store them in the form of starch, oils and proteins. Wild plants store resources in seeds and tubers to later support an emergent young plant. Cultivated crops are effectively storing resources to provide us with food and many have been bred to accumulate much more than would be required otherwise. For example, approximately 80% of a cultivated potato plant's dry weight is contained in its tubers, ten times the proportion in the tubers of its wild relatives (Inoue & Tanaka 1978). Cultivation and breeding has brought about a shift in the partitioning of carbon and nitrogen assimilate between the organs of the plant.

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Precipitation in silicon: Microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100104431 ◽

1988 ◽

Vol 46 ◽

pp. 474-475

Author(s):

R.W. Carpenter

Keyword(s):

Transition Metals ◽

Spatial Resolution ◽

Thin Foil ◽

Precipitation Reaction ◽

High Current ◽

Reaction Products ◽

Carbon And Nitrogen ◽

Dielectric Layers ◽

Precipitation Processes ◽

Areas Of Interest

Interest in precipitation processes in silicon appears to be centered on transition metals (for intrinsic and extrinsic gettering), and oxygen and carbon in thermally aged materials, and on oxygen, carbon, and nitrogen in ion implanted materials to form buried dielectric layers. A steadily increasing number of applications of microanalysis to these problems are appearing. but still far less than the number of imaging/diffraction investigations. Microanalysis applications appear to be paced by instrumentation development. The precipitation reaction products are small and the presence of carbon is often an important consideration. Small high current probes are important and cryogenic specimen holders are required for consistent suppression of contamination buildup on specimen areas of interest. Focussed probes useful for microanalysis should be in the range of 0.1 to 1nA, and estimates of spatial resolution to be expected for thin foil specimens can be made from the curves shown in Fig. 1.

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