Doctoral defence Daniela León Velandia "Mycorrhizal trait distribution and composition in plant communities under natural gradients"

On October 25 at 10:15 Daniela León Velandia will defend her doctoral thesis "Mycorrhizal trait distribution and composition in plant communities under natural gradients" for obtaining the degree of Doctor of Philosophy (in Plant Ecology and Ecophysiology).

Supervisors:
Professor Mari Moora, University of Tartu
RyC Researcher Carlos Guillermo Bueno González, Pyrenean Institute of Ecology - CSIC, Spain
Professor Martin Zobel, University of Tartu

Opponent:
Professor Carlos Urcelay, National University of Cordoba, Argentina

Summary
Mycorrhizal symbiosis is a predominantly mutualistic relationship between plant roots and fungi. The benefits of mycorrhiza to host plants include improved nutrition, protection against pathogens, herbivory resistance, and tolerance to abiotic stress factors.

Plant mycorrhizal traits characterize the structure and function of plant-fungus association. We addressed the following mycorrhizal traits: plant mycorrhizal type, including arbuscular mycorrhizal (AM), ectomycorrhizal (ECM), and ericoid mycorrhizal (ERM) plant species, and plant mycorrhizal status including obligately mycorrhizal (OM), facultatively mycorrhizal (FM), and non-mycorrhizal (NM) plant species.

We characterized the mycorrhizal trait distribution in plant communities in the Pyrenean Mountain range and the Andean páramo. While AM dominance persisted throughout the elevational gradient in páramo, the Pyrenees displayed a slight decrease in AM with elevation and a peak in ECM at mid-elevations. In the Andes, ERM plants were most abundant at the lowest elevations. NM plants thrived at higher elevations in both regions. Across both mountain ranges, the prevalence of FM plants increased and of OM plants declined with elevation.

We also explored the relationship between mycorrhizal trait distribution, productivity and plant diversity in temperate grasslands and found a positive correlation between soil fertility and the prevalence of AM symbiosis, but negative correlation with plant diversity.

Our study showed that mycorrhizal trait patterns vary geographically and ecologically, and mycorrhizal symbiosis influence plant community composition and diversity along elevation and soil fertility gradients. However, the knowledge of the distribution of plant mycorrhizal traits at the level of plant community is yet too little known to draw general conclusions.