TY - JOUR

T1 - 454-sequencing reveals stochastic local reassembly and high disturbance tolerance within arbuscular mycorrhizal fungal communities

AU - Lekberg, Karin Ylva Margareta

AU - Schnoor, Tim

AU - Kjøller, Rasmus

AU - Gibbons, Sean M.

AU - Hansen, Lars H.

AU - Abu Al-Soud, Waleed

AU - Sørensen, Søren Johannes

AU - Rosendahl, Søren

PY - 2012

Y1 - 2012

N2 - 1. Disturbance is assumed to be a major driver of plant community composition, but whether similarprocesses operate on associated soil microbial communities is less known. Based on the assumedtrade-off between disturbance tolerance and competiveness, we hypothesize that a severe disturbanceapplied within a semi-natural grassland would shift the arbuscular mycorrhizal (AM) fungalcommunity towards disturbance-tolerant fungi that are rare in undisturbed soils.2. We used 454-sequencing of the large subunit rDNAregion to characterizeAMfungal communitiesin Plantago lanceolata roots grown in the field for 4 months and exposed either to no disturbanceor to severe disturbance where fungi from undisturbed soil were either permitted orprevented from re-colonizing the disturbed area. This allowed for a distinction between AM fungithat survived the disturbance and those that quickly re-colonized after a disturbance. To identifyAMfungi that could potentially colonize the experimental plants, we also analysed roots from adjacent,undisturbed vegetation.3. We found 32 fungal operational taxonomic units (OTUs) distributed across five knownAMfungalfamilies. Contrary to our expectations, disturbance did not significantly alter the communitycomposition and OTU richness. Instead, OTU abundances were positively correlated across treatments;i.e., common OTUs in undisturbed soil were also common after the severe disturbance.However, the distribution of OTUs within and between plots was largely unpredictable, withapproximately 40%of all sequences within a sample belonging to a single OTU of varying identity.The distribution of two plant species that are often poorly colonized by AMfungi (Dianthus deltoidesand Carex arenaria) correlated significantly with the OTU composition, which may indicatethat host quality could be an additional driver of fungal communities.4. Synthesis. Our results suggest that factors other than disturbance drive the relative abundance ofOTUs in this grassland and question the long-held assumption that communities shift in a predictablemanner after a disturbance event. The reassembly of this fungal community indicates a highcommunity resilience, but substantial local stochasticity and dominance by single OTUs, whichcould be due to priority effects among abundantAMfungi possessing a similar – and high – degreeof disturbance tolerance.

AB - 1. Disturbance is assumed to be a major driver of plant community composition, but whether similarprocesses operate on associated soil microbial communities is less known. Based on the assumedtrade-off between disturbance tolerance and competiveness, we hypothesize that a severe disturbanceapplied within a semi-natural grassland would shift the arbuscular mycorrhizal (AM) fungalcommunity towards disturbance-tolerant fungi that are rare in undisturbed soils.2. We used 454-sequencing of the large subunit rDNAregion to characterizeAMfungal communitiesin Plantago lanceolata roots grown in the field for 4 months and exposed either to no disturbanceor to severe disturbance where fungi from undisturbed soil were either permitted orprevented from re-colonizing the disturbed area. This allowed for a distinction between AM fungithat survived the disturbance and those that quickly re-colonized after a disturbance. To identifyAMfungi that could potentially colonize the experimental plants, we also analysed roots from adjacent,undisturbed vegetation.3. We found 32 fungal operational taxonomic units (OTUs) distributed across five knownAMfungalfamilies. Contrary to our expectations, disturbance did not significantly alter the communitycomposition and OTU richness. Instead, OTU abundances were positively correlated across treatments;i.e., common OTUs in undisturbed soil were also common after the severe disturbance.However, the distribution of OTUs within and between plots was largely unpredictable, withapproximately 40%of all sequences within a sample belonging to a single OTU of varying identity.The distribution of two plant species that are often poorly colonized by AMfungi (Dianthus deltoidesand Carex arenaria) correlated significantly with the OTU composition, which may indicatethat host quality could be an additional driver of fungal communities.4. Synthesis. Our results suggest that factors other than disturbance drive the relative abundance ofOTUs in this grassland and question the long-held assumption that communities shift in a predictablemanner after a disturbance event. The reassembly of this fungal community indicates a highcommunity resilience, but substantial local stochasticity and dominance by single OTUs, whichcould be due to priority effects among abundantAMfungi possessing a similar – and high – degreeof disturbance tolerance.

KW - Faculty of Science

KW - arbuscular mycorrhizal fungi

KW - community composition

KW - disturbance

KW - large ribosomal subunit

KW - massively parallel pyrosequencing

KW - plant–soil (below-ground) interactions

KW - resilience

KW - semi-natural grassland; spatial processes

U2 - 10.1111/j.1365-2745.2011.01894.x

DO - 10.1111/j.1365-2745.2011.01894.x

M3 - Journal article

VL - 100

SP - 151

EP - 160

JO - Journal of Ecology

JF - Journal of Ecology

SN - 0022-0477

IS - 1

ER -