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- Kubart, Ariana, et al.
(författare)
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Patterns of fungal communities among and within decaying logs, revealed by 454 sequencing
- 2012
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 21, s. 4514-4532
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Tidskriftsartikel (refereegranskat)abstract
- Owing to previous methodological limitations, knowledge about the fine-scale distribution of fungal mycelia in decaying logs is limited. We investigated fungal communities in decaying Norway spruce logs at various spatial scales at two environmentally different locations in Sweden. On the basis of 454 pyrosequencing of the ITS2 region of rDNA, 1914 operational taxonomic units (OTUs) were detected in 353 samples. The communities differed significantly among logs, but the physical distance between logs was not found to have a significant effect on whether fungal communities had any resemblance to each other. Within a log, samples that were closer together generally had communities that showed more resemblance to each other than those that were further apart. OTUs characteristic for particular positions on the logs could be identified. In general, these OTUs did not overlap with the most abundant OTUs, and their ecological role was often unknown. Only a few OTUs were detected in the majority of logs, whereas numerous OTUs were rare and present in only one or a few logs. Wood-decaying Basidiomycetes were often represented by higher sequence reads in individual logs than Ascomycete OTUs, suggesting that Basidiomycete mycelia spread out more rapidly when established. OTU richness tended to increase with the decay stage of the sample; however, the known wood decayers were most abundant in less-decomposed samples. The fungi identified in the logs represented different ecological strategies. Our findings differ from previously published sporocarp studies, indicating that the highly abundant fruiting species may respond to environment in different ways than the rest of the fungal community.
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| 2. |
- Ottosson, Elisabet, et al.
(författare)
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Species associations during the succession of wood-inhabiting fungal communities
- 2014
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Ingår i: Fungal ecology. - : Elsevier BV. - 1754-5048 .- 1878-0083. ; 11, s. 17-28
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Tidskriftsartikel (refereegranskat)abstract
- We studied fungal succession in decaying wood by compiling time-series data of fruit body observations. We tested the hypothesis that the presence of a primary species affects the probability of a succeeding species occurring later on the same log. Significant associations were detected for 15 species pairs; these were consistent with earlier findings on cooccurrence patterns in single time surveys. We used enrichment analysis to test if species with particular life-history attributes were more often associated with the occurrence of a succeeding species, or vice versa. White rot fungi and fungi abundant as mycelia were more often associated with the occurrence of succeeding species, compared to brown rot fungi and species with low mycelial abundance. Our results indicate that certain primary species cause priority effects and non-random co-occurrence patterns in the field. These successional patterns are likely to be connected both with substrate modification and species interactions.
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| 3. |
- Ottosson, Elisabet
(författare)
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Succession of wood-inhabiting fungal communities : diversity and species interactions during the decomposition of Norway spruce
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dead wood constitutes an important substrate for biodiversity in boreal forests. As the wood decays, fungal communities develop and species associations are formed. Species interactions are thought to affect community development, but the mycelial dynamics within fungal communities are poorly understood. In this thesis the diversity and temporal dynamics within fungal communities in Norway spruce logs are studied. In particular, patterns of diversity and mechanisms during community assembly are investigated. 454 sequencing is applied to study the less well-known fungal diversity and fine-scale mycelial distribution patterns in decaying logs. The influence of priority effects during community assembly is studied using time-series data from re-inventoried logs. The importance of wood-modification by a primary species and competition is examined in species interaction laboratory experiments. 454 sequencing revealed species-rich fungal communities with diverse ecological roles. Wood-decaying basidiomycetes was found to be the most abundant ecological group, and saprotrophic, mycorrhizal and parasitic fungi were regularly detected. Mycobiont partners of lichens were isolated from interior parts of logs. Fine-scale distribution within logs revealed that resource utilization reflects the life histories of fungal taxa. More decayed samples hosted a higher number of taxa, particularly ascomycetes, whereas wood-decaying basidiomycetes were found in less decayed wood. Priority effects in terms of different mortality factors of trees and the presence of primary decay species were found to affect the subsequent community composition. A species-specific response to primary decay and antagonistic interactions significantly affected decay rate and growth. It is concluded that priority effects are more important in early stages of community development while species more frequent in middle stages of decomposition relies more upon competitive abilities.
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