Strain Identity of the Ectomycorrhizal Fungus Is More Important than Richness in Regulating Plant and Fungal Performance under Nutrient Rich Conditions.

Effects of biodiversity on productivity are more likely to be expressed when there is greater potential for niche complementarity. In soil, chemically complex pools of nutrient resources should provide more opportunities for niche complementarity than chemically simple pools. Ectomycorrhizal (ECM) fungal genotypes can exhibit substantial variation in nutrient acquisition traits and are key components of soil biodiversity.

Contrasting effects of intra- and interspecific identity and richness of ectomycorrhizal fungi on host plants, nutrient retention and multifunctionality.

A major gap in our understanding of biodiversity-ecosystem function relationships concerns the role of intra- and interspecific diversity of mycorrhizal fungi, which are critical for plant fitness, biogeochemical cycling and other processes. Here, we test the hypothesis that the identity and richness of ectomycorrhizal (ECM) fungi at the intra- and interspecific levels affect ecosystem multifunctionality by regulating plant and fungal productivity, soil CO efflux and nutrient retention. Microcosms containing Scots pine (Pinus sylvestris) seedlings colonized by different ECM fungal isolates, in monocultures and mixtures, enabled us to test for both intra- and interspecific identity and richness effects, and transgressive overyielding.