Skip to page content
USDA Forest Service

Research & Development Treesearch

Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help - We Participate  Government Made Easy

Global Forest Information Service

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

(202) 205-8333

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

Publication Information

View PDF (3.3 MB)

Title: N2 fixing alder (Alnus viridis spp.fruticosa) effects on soil properties across a secondary successional chronosequence in interior Alaska

Author: Mitchell, Jennifer S.; Ruess, Roger W.;

Date: 2009

Source: Biogeochemistry. 95: 215-229

Publication Series: Scientific Journal (JRNL)

Description: Green alder (Alnus viridis ssp. fruticosa) is a dominant understory shrub during secondary successional development of upland forests throughout interior Alaska, where it contributes substantially to the nitrogen (N) economy through atmospheric N2 fixation. Across a replicated 200+ year old vegetation chronosequence, we tested the hypotheses that green alder has strong effects on soil chemical properties, and that ecosystem-level N inputs via N2 fixation decrease with secondary successional stand development. Across early-, mid-, and late-successional stands, alder created islands of elevated soil N and carbon (C), depleted soil phosphorus (P), and more acidic soils. These effects translated to the stand-level in response to alder stem density. Although neither N2 fixation nor nodule biomass differed among stand types, increases in alder densities with successional time translated to increasing N inputs. Estimates of annual N inputs by A. viridis averaged across the upland chronosequence (6.6 ± l.2 kg N ha-1 year-1) are substantially less than inputs during early succession by Alnus tenuifolia growing along Alaskan floodplains. However, late-succession upland forests, where densities of A. viridis are highest, may persist for centuries, depending on fire return interval. This pattern of prolonged N inputs to late successional forests contradicts established theory predicting declines in N2-fixation rates and N2 -fixer abundance as stands age.

Keywords: alder, boreal, nitrogen cycling, nitrogen fixation, secondary succession

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.



Mitchell, Jennifer S.; Ruess, Roger W. 2009. N2 fixing alder (Alnus viridis spp. fruticosa) effects on soil properties across a secondary successional chronosequence in interior Alaska. Biogeochemistry. 95: 215-229.


 [ 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.