Sources of inocula influence mycorrhizal colonization of plants in restoration projects: A meta-analysis

Background/Question/Methods

Inoculation may increase mycorrhizal colonization and provide benefits to plants in restoration projects. However, it is unclear whether inoculation has consistent effects across ecosystem types, if it has long-term effects on colonization, and whether types of inocula differ in their effectiveness. To address these issues, we performed a meta-analysis of published restoration studies across a variety of ecosystems to examine the effects of mycorrhizal inoculation on mycorrhizal establishment and plant growth under field conditions. 

Results/Conclusions

Across ecosystem types, we found that inoculation consistently increased the abundance of mycorrhizal fungi in degraded ecosystems (P < 0.001), and thus improved the establishment of plants (P < 0.001). These benefits did not significantly attenuate over time. Moreover, inocula from different sources varied in their effects on mycorrhizal colonization (P = 0.047). Inocula sourced from reference ecosystems and inocula with specific fungal species yielded higher increases in mycorrhizal colonization than did inocula from commercial sources. These results suggest that inocula source matters, and that an initial investment into mycorrhizal inoculation could provide lasting benefits for facilitating the establishment of the below- and aboveground components of restored ecosystems.