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Ectomycorrhizal community structure and function in relation to forest residue harvesting and wood ash applications

Mahmood, Shahid LU (2000)
Abstract
Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied.



In... (More)
Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied.



In total 39 ectomycorrhizal species were detected in the experimental forests located in southern Sweden. At each site five to six species colonised around 60% of the root tips. The dominant species, common to the sites, were Tylospora fibrillosa, Thelephora terrestris and Cenococcum geophilum. Differences between two sites with differing levels of N deposition suggested that community structure may be influenced by N deposition, although site history, location and degree of isolation may also influence species composition. Repeated harvesting of forest residues reduced numbers of mycorrhizal roots in the humus layer to approximately 50% of that in control plots but no shift in the ectomycorrhizal community could be detected. At another site, application of granulated wood ash induced a shift in ectomycorrhizal community structure and three ectomycorrhizal fungi ("ash fungi") were found to colonise ash granules.



Two "ash fungi" showed a superior ability to solubilise stabilised wood ash in laboratory experiments compared to other ectomycorrhizal isolates from the same site. In laboratory microcosms containing intact mycorrhizal mycelia, colonisation of wood ash patches by one "ash fungus" was good whereas colonisation by Piloderma croceum was poor. In a competition experiment with these two fungi, colonisation of spruce roots by the "ash fungus" increased significantly in the presence of wood ash, whereas colonisation by P. croceum decreased. (Less)
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author
opponent
  • Prof Mitchell, Derek, Ireland
organization
publishing date
type
Thesis
publication status
published
subject
keywords
14C allocation, P uptake, Calcium oxalate, Solubilisation, Tricalcium phosphate, Wood ash, Forest residue, N deposition, rDNA, ITS region, PCR-RFLP, Spruce, Ectomycorrhiza, Community structure, Wood ash colonisation, Spruce colonisation, Competition, Ecology, Ekologi
pages
110 pages
publisher
Microbial Ecology, Lund University
defense location
BlÄ Hallen - Ecology Building
defense date
2000-05-16 10:15
external identifiers
  • other:ISRN: SE-LUNBDS/NBME-00/1014+110pp
ISBN
91-7105-136-8
language
English
LU publication?
yes
id
030841f0-7993-4bea-9309-605ad22c5f47 (old id 40501)
date added to LUP
2007-07-31 13:38:51
date last changed
2016-09-19 08:45:05
@phdthesis{030841f0-7993-4bea-9309-605ad22c5f47,
  abstract     = {Ectomycorrhizal fungi form symbiotic associations with tree roots and assist in nutrient-uptake and -cycling in forest ecosystems, thereby constituting a most significant part of the microbial community. The aims of the studies described in this thesis were to evaluate the potential of DNA-based molecular methods in below-ground ectomycorrhizal community studies and to investigate changes in ectomycorrhizal communities on spruce roots in sites with different N deposition, and in sites subjected to harvesting of forest residues or application of wood ash. The ability of selected ectomycorrhizal fungi to mobilise nutrients from wood ash and to colonise root systems in the presence and absence of ash was also studied.<br/><br>
<br/><br>
In total 39 ectomycorrhizal species were detected in the experimental forests located in southern Sweden. At each site five to six species colonised around 60% of the root tips. The dominant species, common to the sites, were Tylospora fibrillosa, Thelephora terrestris and Cenococcum geophilum. Differences between two sites with differing levels of N deposition suggested that community structure may be influenced by N deposition, although site history, location and degree of isolation may also influence species composition. Repeated harvesting of forest residues reduced numbers of mycorrhizal roots in the humus layer to approximately 50% of that in control plots but no shift in the ectomycorrhizal community could be detected. At another site, application of granulated wood ash induced a shift in ectomycorrhizal community structure and three ectomycorrhizal fungi ("ash fungi") were found to colonise ash granules.<br/><br>
<br/><br>
Two "ash fungi" showed a superior ability to solubilise stabilised wood ash in laboratory experiments compared to other ectomycorrhizal isolates from the same site. In laboratory microcosms containing intact mycorrhizal mycelia, colonisation of wood ash patches by one "ash fungus" was good whereas colonisation by Piloderma croceum was poor. In a competition experiment with these two fungi, colonisation of spruce roots by the "ash fungus" increased significantly in the presence of wood ash, whereas colonisation by P. croceum decreased.},
  author       = {Mahmood, Shahid},
  isbn         = {91-7105-136-8},
  keyword      = {14C allocation,P uptake,Calcium oxalate,Solubilisation,Tricalcium phosphate,Wood ash,Forest residue,N deposition,rDNA,ITS region,PCR-RFLP,Spruce,Ectomycorrhiza,Community structure,Wood ash colonisation,Spruce colonisation,Competition,Ecology,Ekologi},
  language     = {eng},
  pages        = {110},
  publisher    = {Microbial Ecology, Lund University},
  school       = {Lund University},
  title        = {Ectomycorrhizal community structure and function in relation to forest residue harvesting and wood ash applications},
  year         = {2000},
}