Thomas Crowther (postdoc)

Untangling the fungal niche through the use of functional traits

Thomas Crowther (Tom) was born in Windhoek, Namibia, but grew up on the northern coast of Wales. As an undergraduate he travelled to the capital, Cardiff, to study zoology and play football (soccer) in Cardiff University. However, following research classes with Prof. Lynne Boddy and an inspirational encounter with Dr. Hefin Jones, Tom became fascinated with ecology and the forces structuring natural communities. Following his undergraduate degree – and the traditional British gap year travelling Asia and South America – Tom returned for a PhD under the co-supervision of the dynamic research duo, Hefin and Lynne. The next four years of both fungal fascination and frustration undoubtedly shaped his academic passions and future research directions.

For his doctoral research, Tom studied interactions between saprotrophic cord-forming fungi and grazing soil invertebrates. His work identified how the selective grazing of certain fungal groups can act as a strong biotic filter, structuring both the community composition and diversity of fungi in temperate forest soil. In a range of studies, he demonstrated how top-down control of fungal communities can have direct consequences for the decomposition of organic material and the exchange of carbon between the soil and the atmosphere.

In 2012, Tom moved to the US to begin a postdoctoral fellowship at Yale University, under the supervision of Dr. Mark Bradford. Initially, his work aimed to generate a more nuanced understanding of the feedbacks between climate change and microbial release of carbon into the atmosphere. This work showed how fungal thermal acclimation, and interactions with other soil biota, can dampen the strength of the feedback between soil respiration and global climate change. During this time, Tom’s focus shifted towards building a more detailed knowledge of fungal biogeography, so that we can begin to understand the patterns of fungal-mediated carbon cycling across landscapes.

Earlier this year, Tom was invited by the MSA Student Section to speak at the MSA annual meeting in East Lansing, in the student-run symposium entitled ‘Fungal Functional Traits in a Changing World.’ This symposium provided him with a valuable opportunity to meet and exchange ideas with research leaders in similar fields. The overwhelming take-home from this symposium was the value of functional traits in community and ecosystem ecology. Although the use of trait-based approaches has exploded in plant and animal ecology, research in fungal ecology generally focuses on species names and taxonomic groups. As community ecologist Brian McGill says, “statements about traits provide generality and predictability, whereas nomenclatural ecology tends toward highly-contingent rules and special cases.” It is likely that a shift in focus – from taxonomic identities to functional traits – can transform our search for the fundamental processes governing patterns in fungal communities across time and space. This symposium inspired Tom to write a manuscript outlining the transformative potential of functional traits within fungal ecology.

This manuscript, “Untangling the fungal niche: the trait-based approach,” is now published in Frontiers in Microbiology [1] and provides a framework for the use of functional traits in fungal ecology. The paper was designed specifically for mycologists, guiding the selection of trait-based approaches to answer questions in community and ecosystem ecology. In the review, Tom and co-authors describe how the use of functional traits can improve the search for the physiological trade-offs that govern fungal community ecology. Specifically, it shows that, although neutral processes appear to determine the distribution of fungal taxa, habitat filtering and biotic interactions are likely to govern the distribution of important functional traits. Improving our understanding of these niche processes in fungal ecology is essential if we are to generate predictable maps of fungal biogeography at broad spatial scales.

Since the completion of this manuscript, Tom has been working to generate a database of over 100 functional traits for a collection of 50 fungi collected from across North America. Working in close collaboration with Yale PhD student Daniel Maynard and Dr. Daniel Lindner from the USDA Forest Products Laboratory, the work aims to generate an understanding of the fundamental trade-offs that govern patterns in fungal biogeography. Ultimately, Tom hopes to link these fungal community characteristics with traits associated with decomposition to generate predictable patterns of fungal-mediated nutrient processes rates at a global scale.

Following his fellowship in Yale, Tom will begin a second postdoc at the Netherlands Institute of Ecology (NIOO) in Wageningen, working with Prof. Wim van der Putten, Prof. Wietse de Boer, and Dr. Annemieke van der Wal. Tom will use a range of culture and molecular techniques to expand the growing trait database, to include effect traits associated with wood decomposition and carbon cycling. After this position, Tom aims to pursue a more permanent position within academia, and hopes to continue building on this work in search of the fundamental principles governing fungal community organization.

By Thomas Crowther
Yale University

[1] Crowther, T.W., Maynard, D.S., Crowther, T.R., Peccia, J., Smith, J., & Bradford, M. A. (2014). Untangling the fungal niche: the trait-based approach. Frontiers in Microbiology, doi: 10.3389/fmicb.2014.00579.

Tom’s full list of publications is available on Google Scholar.

A group of fungi near one of Tom’s Soil Warming and Nitrogen (SWaN) plots at Harvard Forest.