Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

GeoTreesearch


Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

(1.0 MB)

Title: Nitrogen isotope patterns in Alaskan black spruce reflect organic nitrogen sources and the activity of ectomycorrihizal fungi

Author: Mayor, Jordan R.; Schuur, Edward A.G.; Mack, Michelle C.; Hollingsworth, Teresa N.; Bääth, Erland.

Date: 2012

Source: Ecosystems. 15: 819-831

Publication Series: Scientific Journal (JRNL)

Description: Global patterns in soil, plant, and fungal stable isotopes of N (15N) show promise as integrated metrics of N cycling, particularly the activity of ectomycorrhizal (ECM) fungi. At small spatial scales, however, it remains difficult to differentiate the underlying causes of plant 15N variability and this limits the application of such measurements to better understand N cycling. We conducted a landscape-scale analysis of 15N values from 31 putatively N -limited monospecific black spruce (Picea mariana) stands in central Alaska to assess the two main hypothesized sources of plant 15N variation: differing sources and ECM fractionation. We found roughly 20% of the variability in black spruce foliar N and 15N values to be correlated with the concentration and 15N values of soil NH4 + and dissolved organic N (DON) pools, respectively. However, 15N-based mixing models from 24 of the stands suggested that fractionation by ECM fungi obscures the 15N signature of soil N pools. Models, regressions, and N abundance data all suggested that increasing dependence on soil DON to meet black spruce growth demands predicates increasing reliance on ECM derived N and that black spruce, on average, received 53% of its N from ECM fungi. Future research should partition the 15N values within the soil DON pool to determine how choice of soil 15N values influence modeled ECM activity. The C balance of boreal forests is tightly linked to N cycling and 15N values may be useful metrics of changes to these connections.

Keywords: 15N, black spruce, denitrifier method, dissolved organic nitrogen, ectomycorrhiza, isotope fractionation, mixing models

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

XML: View XML

Citation:


Mayor, Jordan R.; Schuur, Edward A.G.; Mack, Michelle C.; Hollingsworth, Terresa N.; Bääth, Erland. 2012. Nitrogen isotope patterns in Alaskan black spruce reflect organic nitrogen sources and the activity of ectomycorrhizal fungi. Ecosystems.15: 819-831.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.