Nursing Back to Health: Shrubs Facilitate the Restoration of Native Forbs with Reductions in Non-Native Competition in an Invaded Arid Shrubland

Restoring native species to invaded arid ecosystems is challenging as non-native species often limit native species establishment, which limits success. Nurse plant facilitation may be utilized to improve native species establishment through reductions in abiotic and biotic stresses but this has not yet been tested for native forb restoration in invaded arid ecosystems. Five native forb species were seeded in shrub and open microsites, with and without exclosures. Non-native removals were done to determine if shrubs could facilitate native forbs establishment in an invaded arid shrubland. Shrubs facilitated native species, and interestingly, most natives co-existed with non-natives. However, non-native removals had a large positive effect for two less competitive native species. Exclosures overall were not effective at increasing native density. Seeding natives with shrubs and non-native removals are recommended as effective strategies for increasing native species establishment in invaded arid systems.