A trait-based approach to unlock the secrets of fungal soil aggregation mechanisms

• Applicant: Professor Matthias C. Rillig, Ph.D.
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems ; Microbial Ecology and Applied Microbiology
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 263671284

• Final Report Year: 2020

Final Report Abstract

Humankind depends on the sustainability of soils for its survival and well-being. The functions and services provided by soil all depend upon its inherent structure. The soil structure is a result of the arrangement of soil particles into aggregates and associated pore networks. Despite the unprecedented role of soil aggregation for soil functioning, our understanding of soil biota - and especially filamentous fungi - contributions to soil aggregation remains highly fragmented. This is primarily caused by the focus on management aspects driving previous works on that topic. In the scope of this project we aimed to investigate the importance of filamentous saprobic fungi on soil aggregation and unravel potential mechanism. We established a set of 31 fungal strains comprising three phyla (Ascomycota, Basidiomycota and Mucoromycota) which were isolated from the same soil. For these strains we collected 15 traits under standardized conditions to characterize their morphological, chemical and biotic features. This database granted us insight into unexpected variability in the expression of and tradeoffs between fungal traits. Our investigations led to the identification of three fungal characteristics that clearly determines the fungal capability to affect and modulate the soil structure; these are biomass density, i.e. the density with which a mycelium grows (positive effects), leucine aminopeptidase activity (negative effects) and phylogeny. Our project has achieved major progress to applying a trait-based approach to mechanisms underlying fungal contributions to soil aggregation.

Publications

• 2015. Understanding mechanisms of soil biota involvement in soil aggregation: A way forward with saprobic fungi? Soil Biology & Biochemistry 88, 298-302
  Lehmann A, Rillig MC
  
• 2017. Mycorrhizas in soil aggregation. In: Johnson NC, Gehring C, Jansa J. Mycorrhizal mediation of soil. Elsevier, MA, USA
  Lehmann A, Leifheit EF, Rillig MC
  
• 2017. Soil aggregates as massively concurrent evolutionary incubators. ISME Journal 11: 1943-1948
  Rillig MC, Muller L, Lehmann A
  
• 2017. Soil biota contributions to soil aggregation. Nature Ecology and Evolution 1: 1828-1825
  Lehmann A, Zheng W, Rillig MC
  
• 2018. Growth rate trades off with enzymatic investment in soil filamentous fungi
  Zheng W, Lehmann A, Ryo M, Vályi KK, Rillig MC
  
• 2018. Intransitive competition is common across five major taxonomic groups and is driven by productivity, competitive rank and functional traits. Journal of Ecology 106: 852-864
  Soliveres S, Lehmann A, Boch S, Altermatt F, Carrara F, et al.
  
• 2019. Tradeoffs in hyphal traits determine mycelium architecture in saprobic fungi. Scientific Reports 9: 14152
  Lehmann A, Zheng W, Soutschek K, Roy J, Yurkov A, Rillig MC
  
• 2020. Fungal Traits Important for Soil Aggregation. Frontiers in Microbiology 10: 1-13
  Lehmann A, Zheng W, Ryo M, Soutschek K, Roy J, Rongstock R, Maaß S, Rillig MC