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? 2) Effects on plant populations and communities 3) Effects on biodiversity 4) Impacts on atmospheric chemistry and global warming

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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 Presentation

Transcript of REWM 3500 Rangeland Plant Ecophysiology November 30, 2009

Page 1: REWM 3500 Rangeland Plant Ecophysiology November 30, 2009

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

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Connectivity

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Anthropogenic production of reactive nitrogen

Natural background rate

From Galloway 2005

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Human impacts on the global N cycleAtmospheric deposition of reactive N

From Galloway 2005

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Sinks Canyon, Fremont County, WyomingAnnual inorganic nitrogen deposition 1984-2007

http://nadp.sws.uiuc.edu

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From Galloway 2005

Human impacts on the global N cycle

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Sources, feedbacks and impacts of enhanced N fixation

From Galloway 2005

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Atmospheric concentrations of nitrous oxide over the last 10,000 years and since 1750 (inset)

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Terms and concepts to know:

nitrogen fixationabiotically fixed N2

biologically fixed N2

anthropogenic N fixationHaber processmineralizationnitrificationdenitrificationnitrous oxide (N2O)