Mycorrhizae and nutrient supply in desert transitions

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Mycorrhizae and nutrient supply in desert
transitions
W. Swenson, M. F. Allen, E. B. Allen, K.
Pregitzer University of California,
Riverside Michigan Technological University
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Regional Deposition-Tonnesen
Total N Deposition (Gail Tonnesen and
colleagues CE-CERTUC Riverside)
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N transport and transformation
soil mycorrhizal fungus
plant
NO3-
NO3-
NO3-
NH4 NH4
NH4

glutamate
glutamate
glutamine glutamine
sucrose glycine glycine
CO2
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Using minirhizotron in the field
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EM- pinyon pine
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AM
AM plants Juniper Creosote Bush
Grasses
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Fertilization Grasslands(1997, Allen and Allen)
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MacKenzie Flats
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Pinyon-Juniper woodland
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Goat Draw Pinyon-Juniperfertilization
experiments100 kg/ha/y
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Soil Fertilization PJ
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Leaf Responses to Fertilization PJ
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EM Dynamics pinyon pine
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AM Dynamics juniper
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EM Cohort Survival- example
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Juniper productivity
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Junipers, N and Bears
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N and Piñon mortality
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