Ectomycorrhizal fungal succession coincides with shifts in organic nitrogen availability and canopy closure in post-wildfire jack pine forests.
Oecologia
; 172(1): 257-69, 2013 May.
Article
in En
| MEDLINE
| ID: mdl-23053232
ABSTRACT
Successional changes in belowground ectomycorrhizal fungal (EMF) communities have been observed with increasing forest stand age; however, mechanisms behind this change remain unclear. It has been hypothesized that declines of inorganic nitrogen (N) and increases of organic N influence changes in EMF taxa over forest development. In a post-wildfire chronosequence of six jack pine (Pinus banksiana) stands ranging in age from 5 to 56 years, we investigated EMF community composition and compared shifts in taxa with detailed soluble inorganic and organic N data. Taxa were identified by internal transcribed spacer rDNA sequencing, and changes in community composition evaluated with non-metric multi-dimensional scaling (NMDS). Dissimilarities in the community data were tested for correlations with N variables. We observed a successional shift along NMDS axis 1 from such taxa as Suillus brevipes and Thelephora terrestris in sites age 5 and 11 to species of Cortinarius and Russula, among others, in the four older sites. This change was positively correlated with soluble organic N (SON) (r(2) = 0.902, P = 0.033) and free amino-acid N (r(2) = 0.945, P = 0.021), but not inorganic N. Overall, our results show a successional shift of EMF communities occurring between stand initiation and canopy closure without a change in species of the dominant plant-host, and associated with SON and free amino-acid N in soil. It is uncertain whether EMF taxa are responding to these organic N forms directly, affecting their availability, or are ultimately responding to changes in other site variables, such as belowground productivity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pinus
/
Mycorrhizae
/
Nitrogen Cycle
/
Fires
Type of study:
Prognostic_studies
Language:
En
Journal:
Oecologia
Year:
2013
Document type:
Article
Affiliation country:
United States
Publication country:
ALEMANHA
/
ALEMANIA
/
DE
/
DEUSTCHLAND
/
GERMANY