Document


Title

Nitrogen alters carbon dynamics during early succession in boreal forest
Document Type: Journal Article
Author(s): Steven D. Allison; Tracy B. Gartner; Michelle C. Mack; Krista L. McGuire; Kathleen K. Treseder
Publication Year: 2010

Cataloging Information

Keyword(s):
  • age classes
  • Betula glandulosa
  • biomass
  • black spruce
  • boreal forest
  • boreal forests
  • carbon
  • catastrophic fires
  • cellulose
  • coniferous forests
  • decomposition
  • decomposition
  • enzymes
  • extracellular enzyme
  • fertilization
  • fertilizers
  • Festuca altaica
  • fire case histories
  • fire frequency
  • fire management
  • forest management
  • fungi
  • fungi
  • grasses
  • Ledum
  • litter
  • Lupinus arcticus
  • nitrogen
  • nitrogen fertilization
  • nutrient cycling
  • organic soils
  • Picea mariana
  • shrubs
  • soil carbon
  • soil management
  • soil nutrients
  • soil respiration
  • soils
  • succession
  • succession
  • Vaccinium
  • wildfires
  • wood
Record Maintained By:
Record Last Modified: May 16, 2019
FRAMES Record Number: 48593
Tall Timbers Record Number: 24765
TTRS Location Status: Not in file
TTRS Call Number: Not in File
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Boreal forests are an important source of wood products, and fertilizers could be used to improve forest yields, especially in nutrient poor regions of the boreal zone. With climate change, fire frequencies may increase, resulting in a larger fraction of the boreal landscape present in early-successional stages. Since most fertilization studies have focused on mature boreal forests, the response of burned boreal ecosystems to increased nutrient availability is unclear. Therefore, we used a nitrogen (N) fertilization experiment to test how C cycling in a recently-burned boreal ecosystem would respond to increased N availability. We hypothesized that fertilization would increase rates of decomposition, soil respiration, and the activity of extracellular enzymes involved in C cycling, thereby reducing soil C stocks. In line with our hypothesis, litter mass loss increased significantly and activities of cellulose- and chitin-degrading enzymes increased by 45-61% with N addition. We also observed a significant decline in C concentrations in the organic soil horizon from 19.5 ± 0.7% to 13.5 ± 0.6%, and there was a trend toward lower total soil C stocks in the fertilized plots. Contrary to our hypothesis, mean soil respiration over three growing seasons declined by 31% from 78.3 ± 6.5 mg CO2-C m-2 h-1 to 54.4 ± 4.1 mg CO2-C m-2 h-1. These changes occurred despite a 2.5-fold increase in aboveground net primary productivity with N, and were accompanied by significant shifts in the structure of the fungal community, which was dominated by Ascomycota. Our results show that the C cycle in early-successional boreal ecosystems is highly responsive to N addition. Fertilization results in an initial loss of soil C followed by depletion of soil C substrates and development of a distinct and active fungal community. Total microbial biomass declines and respiration rates do not keep pace with plant inputs. These patterns suggest that N fertilization could transiently reduce but then increase ecosystem C storage in boreal regions experiencing more frequent fires. © 2010 Elsevier Ltd. All rights reserved.

Citation:
Allison, S. D., T. B. Gartner, M. C. Mack, K. McGuire, and K. Treseder. 2010. Nitrogen alters carbon dynamics during early succession in boreal forest. Soil Biology & Biochemistry, v. 42, no. 7, p. 1157-1164. 10.1016/j.soilbio.2010.03.026.