Abstracts |
Mycorrhizal symbiosis is a widespread association between plant roots and mycor-rhizal fungi, which is thought to contribute to plant niche differentiation and expan-sion. However, this has so far not been explicitly tested. To address the effect of mycorrhizal symbiosis on plants’ realized niches, we ad-dressed how mycorrhizal status (i.e. the frequency of occurrence of mycorrhizal symbiosis), flexibility (i.e. the ability to grow both with and without mycorrhizal symbiosis) and type of a plant species affect the realized niche optima, widths and volumes. For this, we used co- occurrence data from the flora of the Netherlands along soil fertility, moisture, pH, salinity, light and temperature gradients. Phylogenetic dependency of the species was taken into account using phylogenetic generalized least squares models. We show that facultatively and flexibly mycorrhizal plants have the widest niches compared to non- mycorrhizal and obligately mycorrhizal, and inflexible plants re-spectively. Among obligate plant symbionts, ecto- and ericoid mycorrhizal plants exhibited the widest niches compared to plants with other mycorrhizal types. Also, plants with different mycorrhizal statuses and types differed in their realized niche optima. The results indicate that mycorrhizal symbiosis mediates plant niche dif-ferentiation and expansion, facilitating the understanding of current distribution patterns of plant species, as well as predicting shifts in plant distribution and dominance due to environmental changes. |