Inoculant-Supported Restoration (ISR)
Climate change is increasing the need for ecological restoration across the planet. Californians are rising to the challenge by investing millions of dollars in ecosystem restoration projects thanks to voter-approved funds like Measure AA and Propositions 1 and 68. The critical nature of this work and the swell of support presents exciting opportunities for innovation. Here we share our initial findings of a restoration approach that directly addresses climate change by adding a new spin to a tried-and-true approach. We invite our conservation colleagues to test and improve on it as we collectively work towards shared conservation goals.
Over a 2 year study, we compared trees planted with whole-soil inocula sourced from a nearby region with warm and dry conditions to trees planted without any inoculum. Our study species were Arroyo Willow, Valley Oak, Coast Live Oak, and Douglas Fir. We did not have significant findings to report for Douglas Fir. For the Oak and Willow species, we found:
- Strong evidence that ISR more than tripled the odds of survival in Arroyo Willow and Coast Live Oak
- Arroyo Willow and Coast Live Oak had higher rates of root colonization by ectomycorrhizae
- The odds of acorn germination doubled for Coast Live Oak and Valley Oak
- There was no evidence of any negative effects of ISR