Research School for Socio-Economic and
Natural Sciences of the Environment
Research School for Socio-Economic and
Natural Sciences of the Environment

Lisette Bakker

Date: 30 May 2018
Time: 13:30 - 15:00
Location: Aula, building 362, Gen. Foulkesweg 1, Wageningen

Dissertation title:

Group: Wageningen University, Nature Conservation and Plant Ecology
Promotors: L. Mommer
Copromotors: Dr. J. van Ruijven

Extra information:


There is consensus about the positive relationship between plant diversity and productivity. Moreover, plant diversity may have a positive effect on drought resistance of plant communities. However, the underlying mechanisms for these positive biodiversity effects are still debated. In this thesis, I investigated the mechanisms underlying biodiversity effects by focussing on root traits. My results showed that root traits can explain a specific part of the biodiversity effect: selection effects, meaning that deeper rooting species were larger in monocultures and in mixtures. Root trait diversity could not explain complementarity effects, which are potentially related to positive biotic interactions. However, when measuring at the scale of the individual rather than plot, deep-rooting individuals increased biomass when growing with shallow-rooting neighbours, supporting the importance of rooting depth diversity. Further, drought resistance was not increased in mixtures. Contrarily, drought decreased complementarity effects. We found no role for roots, but mitigation via plant cover.