Soil inoculation enhances early‐phase reintroduction success in two rare plant species
Sina Bohm, Rosa Boone, Ilse J. G. Verkerk, Evanne Y. Slagter, Niels C. A. M. Wagemaker, Bjorn Robroek, Philippine VergeerAbstract
Introduction
Reintroduction for conservation is an important measure to restore populations of vulnerable plant species. However, reintroduction success rates are relatively low. Inoculating reintroduced plants with facilitative microorganisms from native populations may enhance their performance.
Objectives
This study investigates whether inoculation using soil from conspecific populations can increase early‐phase reintroduction success in two rare plant species, Hypericum pulchrum and Solidago virgaurea .
Methods
For both species, seedlings from three native donor populations in the Netherlands were propagated in a greenhouse under different inoculation treatments: living soil from one of the three donor sites, sterilized soil from one of the donor sites, and a “no soil inoculum” control. Seedlings and inoculum origins were assigned in a full reciprocal design to test for potential home‐soil effects. After 6 months, individuals were transplanted to suitable reintroduction field sites, one site for each species. Plant performance was monitored for 2 years. Soil microbial communities were assessed at the reintroduction and donor sites and linked to plant performance.
Results
Plants responded positively to inoculation with living soil. Hypericum pulchrum exhibited higher survival, growth, and flowering, and S. virgaurea had higher flowering percentages in the living inoculum treatment as compared to the two control groups. These responses were independent of inoculum origin. Several bacterial and fungal taxa were transferred through inoculation, and particular taxa were positively associated with plant performance.
Conclusion
Our study demonstrates that reintroductions are important plant conservation strategies and that implementing soil inoculations in reintroductions can improve survival and performance of reintroduced plants.