Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Pec, Gregory [1], Stotz, Gisela [2], Carrigy, Alec [2], Cahill, James [2].

Changes in the community structure of fungi driven by habitat filtering in the aspen parkland.

Identifying the mechanisms that structure ecological communities is a major goal of ecological research. Despite evidence that belowground communities, in particular, fungi, differ in habitat and diversity due to variation in both abiotic and biotic conditions, it is unclear whether these patterns are driven by similar or different processes according to differences in their trophic lifestyles as decomposers, pathogens or symbiotrophs. Here, we used the aspen parkland, a savanna-type habitat, which varies at small spatial scales in species composition and abiotic resources as a model system to disentangle the relative roles of habitat (i.e., soils versus roots), biotic factors (i.e., vegetative composition and richness) and soil abiotic factors (i.e., N, P, pH, moisture) in influencing the richness and composition of fungi. Overall, there were twice as many fungi, particularly symbiotrophs, present within soils as on roots. There was a positive relationship between the richness of pathogenic fungi in soils and soil P, while high soil moisture levels led to a decline in both the richness of decomposers and pathogens. There were also differences in the composition of symbiotrophic and pathogenic fungi among habitats. In soils, symbiotrophs correlated most strongly with soil P and moisture, while pathogens correlated with soil N. On roots, compositional shifts in symbiotrophs were driven by variation in plant community composition. The composition of pathogenic fungi was highly correlated with invasive smooth brome, while the composition of decomposing fungi was invariant across both habitat and environmental conditions. Variance partitioning analyses revealed that the independent effects of habitat (39%) and vegetative composition (12%) accounted for most of the variation explained in the composition of symbiotrophs. There were no independent or shared effects that contributed to the variation in the composition of decomposers, while the independent effect of soil abiotic factors (15%) contributed to most of the variation explained in the composition of pathogens. Taken together, our findings suggest that different mechanisms influence the richness and composition of fungi based on their trophic lifestyles. Furthermore, fungi found on roots are recruited from the surrounding soil fungal community and driven by biotic components as opposed to abiotic conditions, which seem to regulate the composition of fungi found in soils.

1 - University of Alberta, Renewable Resources, 751 General Services Building, Edmonton, AB, T6G 2H1, Canada
2 - University of Alberta, Biological Sciences, Biological Sciences Building, CW405, Edmonton, AB, T6G 2E9, Canada

Keywords:
Fungi
Community Ecology
Soil environment
Aspen parkland.

Presentation Type: Oral Paper
Session: 24, Symbioses: Plant, Animal, and Microbe Interactions
Location: Fort Worth Ballroom 5/Omni Hotel
Date: Tuesday, June 27th, 2017
Time: 11:45 AM
Number: 24008
Abstract ID:545
Candidate for Awards:None