PhD defense | Allan Ecology Lab

On the 21^st of January in 2020, the first two PhD students of the PaNDiv project successfully defended their PhD.

Congratulations to Dr. Pichon and Dr. Cappelli!

Noémie investigated the effect of nitrogen enrichment and found that the direct and indirect effects of nitrogen enrichment were of similar importance in affecting ecosystem functioning. She found that species richness increased multifunctionality, as did functional diversity, while added nitrogen dampened these positive effects. The most functionally diverse communities were even slightly better at providing multiple functions than the low diversity fertilized communities. This suggests that managing for diversity can not only increase in productivity, but also provide multiple benefits compared to intensive systems. bioRχiv publication, Functional Ecology article, Functional Ecology blogpost

Seraina looked at the effect of removing plant pathogens (by applying fungicide) and found support for the growth-defense trade-off hypothesis, which states that fast growing species are less defended. Growth strategy (specific leaf area) was the main driver of infection. Surprisingly, there was no direct effect of nitrogen enrichment on fungal infection. She also found consistent negative selection effects and neutral to positive complementarity effects for all functions. The mechanisms underlying the diversity effects varied between the functions highlighting the importance of a high species diversity for the maintenance of multiple ecosystem functions. bioRχiv publication

The PaNDiv project now goes into its second phase and continues to explore new and exciting questions about the direct and indirect effects of global change drivers on above- and belowground invertebrate, fungal and plant communities and functioning.

Dr Pichon Dr. Pichon
with Prof. Matthias Erb (chair), Prof. Jasper van Ruijven (external examiner) and Prof. Eric Allan (supervisor)