rewm 3500 rangeland plant ecophysiology november 30, 2009
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REWM 3500 Rangeland Plant Ecophysiology November 30, 2009 Human impact on the global nitrogen cycle – how will rangelands respond? Natural vs Anthropogenic Nitrogen Fixation Consequences of altered N biogeochemistry 1)Where is this nitrogen going? - PowerPoint PPT PresentationTRANSCRIPT
REWM 3500Rangeland Plant EcophysiologyNovember 30, 2009
Human impact on the global nitrogen cycle – how will rangelands respond?
Natural vs Anthropogenic Nitrogen Fixation
Consequences of altered N biogeochemistry1) Where is this nitrogen going?2) Effects on plant populations and communities3) Effects on biodiversity4) Impacts on atmospheric chemistry and global warming
Connectivity
Anthropogenic production of reactive nitrogen
Natural background rate
From Galloway 2005
Human impacts on the global N cycleAtmospheric deposition of reactive N
From Galloway 2005
Sinks Canyon, Fremont County, WyomingAnnual inorganic nitrogen deposition 1984-2007
http://nadp.sws.uiuc.edu
From Galloway 2005
Human impacts on the global N cycle
Sources, feedbacks and impacts of enhanced N fixation
From Galloway 2005
Atmospheric concentrations of nitrous oxide over the last 10,000 years and since 1750 (inset)
Terms and concepts to know:
nitrogen fixationabiotically fixed N2
biologically fixed N2
anthropogenic N fixationHaber processmineralizationnitrificationdenitrificationnitrous oxide (N2O)