Can consideration of metacommunity theory improve estimates of community dynamics for arbuscular mycorhizal fungi?
Microbial Ecology and Applied Microbiology
Final Report Abstract
Despite their ubiquity in terrestrial ecosystems, arbuscular mycorrhizal fungi (AMF) likely frequently experience dispersal constraints, which could give rise to meta-community dynamics. We only maintain a limited understanding of how AMF dispersal affects the functioning of the symbiosis. In this project we combined observational and experimental approaches to assess the degree to which meta-community dynamics influence the community structure of AMF in the roots of their hosts. In this project we combined monitoring temperate forests and carrying out three controlled experiments which massive in size (90 cm x 90 cm x 20 cm; w x l x h) experimental units to show that the spatial structure of plant hosts and their AMF inoculum consistently altered AMF colonization but had minimal effects on AMF community structure. We observed that mixing habitat types (i.e. fertilizes and unfertilized soil) or structuring the experimental units in ways that required both long-distance and short-distance AMF hyphal dispersal increased root colonization (and thus most likely mycorrhizal functioning). At the same time we observed no differences in alpha- or gamma- diversity in AMF communities, even though AMF-community structure remained non-random (i.e. showed segregation patterns). Even though diversity did not differ with our treatments, we observed that invariable (i.e. consisting of a single habitat) continuous landscapes were more predictable and showed a lower community turnover which is in line with predictions from meta-community theory. Arbuscular mycorrhizal fungi are most likely to experience dispersal constraints in urban and agricultural landscapes as well as at woody habitats. In the case of agricultural landscapes, the growth settings should select for short-distance dispersal traits (i.e. there are uniform distances across crop individuals, which ease the proliferation of AMF species from close by islands of AMF diversity) whereas at woody habitats for a combination of long- and short-distance dispersal (i.e. distances between AMF-associating plants most likely vary in time and space). Based on the results of our study, plant hosts in woody habitats could as a result experience a higher stochasticity in relation to harbouring AMF community structure than other hosts. This might actually benefit AMF-associating plants in forests, on the longer term. Woody plants, in particular, experience a high mortality at early life-stages. If plant fitness depends on the benefits they acquire from associating with AMF (as we suggest in our earlier work), stochasticity in AMF community structure, could render plant fitness more variable in time and in space and secure that the surviving individuals are those that associate with strongly mutualistic AMF.
Publications
- 2019. Latitudinal constraints in responsiveness of plants to arbuscular mycorrhiza: The ‘sun-worshipper’ hypothesis. New Phytologist 224, 552-556
Veresoglou SD, Chen BD, Fischer MM, Helgason T, Mamolos AP, Rillig MC, Roldán A, Johnson D.
(See online at https://doi.org/10.1111/nph.15918) - 2020. Excluding arbuscular mycorrhiza lowers variability in soil respiration but slows down recovery from perturbations. Ecosphere 11, e03308
Veresoglou SD, Yang G, Mola M, Manntschke A, Mating M, Forstreuter M, Rillig MC
(See online at https://doi.org/10.1002/ecs2.3308) - 2020. Neighbours of arbuscular-mycorrhiza associating trees are colonized more extensively by arbuscular mycorrhizal fungi than their conspecifics in ectomycorrhiza dominated stands. New Phytologist 227, 10-13
Grünfeld L, Wulf M, Rillig MC, Manntschke A, Veresoglou SD
(See online at https://dx.doi.org/10.17169/refubium-27332) - 2021. Disentangling the relative importance of spatio-temporal parameters and host selectivity in shaping AMF communities in temperate forests. bioRxiv
Grünfeld L, Mola M, Wulf M, Hempel S, Veresoglou SD
(See online at https://doi.org/10.1101/2021.02.16.431389)
