Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Research on Microbes
Microbiology Experts
Online Submission
Access Statistics

Site Visitors

blog tracking

Soil Sci. Soc. Am. J.
Vol.66, No. , 2002, Pages:

Changes in Microbial Nitrogen Across a 100-Year Chronosequence of Upland
Hardwood Forests

Travis W. Idol,* Phillip E. Pope, and Felix Ponder, Jr.


Soil microorganismsmediate many of the major processes involved in soil N cycling. Also, they are strong competitors with plants for available soil N. Thus, changes in microbial N because of forest harvesting may have significant impacts on N availability and overall forest N cycling. A chronosequence of upland hardwood forest stands in southern Indiana, USA, ranging in age from 1 to 100 yr since last harvest, was chosen to evaluate changes in microbial N with stand development. Microbial N was measured in the A and B soil horizons during different seasons from 1997 to 1999. Peak levels of microbial N were highest in the youngest forest stand (1 to 3 yr old), but seasonal variability was greater than differences by stand age. Microbial N concentration (mg kg-1) varied significantly by season and soil horizon within stands ranging in age from 1 to 30 yr since harvest, but not in the mature, 80- to 100-yr-old stand. There were few significant differences in microbial N content (kg ha-1). Harvesting did not appear to have long-term effects on microbial N, but spatial variability in microbial N appeared to be greater in the younger forest stands.

Keywords:Microbial Nitrogen, Soil microorganisms, chronosequence, Organis farming.

Corresponding author: Phone:xxxxxxxxxxx Fax: xxxxxxxxxxx.

E-mail: twidol@ucdavis.edu


Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution