Plant coexistence has puzzled scientists for a long time and one of the proposed underlying mechanisms is minimizing competition by niche differentiation. According to this, in order to coexist, species must differ in their realized niches (i.e. species must have distinct resource and habitat requirements). PhD student Maret Gerz with co-authors investigated whether and how the associations with mycorrhizal fungi could alter the realized niches of plant species. In a paper published in Journal of Ecology, it was found that, indeed, plants with different mycorrhizal statuses and types had distinct environmental preferences, but also that the range of environmental conditions which plant species tolerate, are dependent on whether they are obligately, facultatively or non-mycorrhizal, or which mycorrhizal type they form. Specifically, facultatively mycorrhizal, and ecto- and ericoid mycorrhizal plants had wider niches than other plants. These differences indicate that mycorrhizal symbiosis is an important contributing factor to plant coexistence.

Gerz, M.; Bueno, C. G.; Ozinga, W. A.; Zobel, M. & Moora, M. 2017. Niche differentiation and expansion of plant species are associated with mycorrhizal symbiosis. Journal of Ecology doi: 10.1111/1365-2745.12873.