Background
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Northern latitude forests play a significant role in the uptake
and storage of atmospheric carbon, and of the various nutrients
needed by forests, nitrogen is critically important. A fair amount
of nitrogen reaches ecosystems via atmospheric deposition as a
direct result of human activity, and this nitrogen is playing
an increasing role in the fertilization of terrestrial and aquatic
ecosystems. The complexity of atmosphere-forest interactions presents
a significant challenge, one whose study requires expertise in
atmospheric chemistry and speciated atmospheric fluxes as well
as in plant physiology, soil microbiology and biochemistry, nutrient
transfer and hydrologic balance. We are interested in engaging
and bringing together for effective collaborative research, the
atmospheric and biospheric research communities in the process
of preparing a science plan to define the best possible approach
to addressing questions involving nitrogen, and the connection
to the carbon cycle. |
Detailed Background Description
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Prioritized Objectives
While we work to bring together the necessary participants for a coordinated
and integrated effort, the PROPHET science team will be working to address
some of the fundamental holes in our understanding of the deposition
of speciated atmospheric nitrogen to forests. Building on the
strength of our experience in ambient atmospheric composition, we will
focus our attention on fluxes of nitrogen species to the forest canopy
and to the soils: The following is a list of species that will
be the immediate focus of our attention:
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Determine
fluxes, and relative fluxes of HNO3, NO, NO2, particle nitrate,
PANs and RONO2s.
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Determine
the fractional throughfall for these species.
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Determine
their fate after deposition.
- Investigate the importance of direct foliar uptake of atmospheric
nitrogen compounds.
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Examine
canopy surface transformation.
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