Mycorrhizal association with native and invasive cordgrass Spartina spp. in San Francisco Bay, California

Abstract

For the first time, hybrids of Spartina alterniflora × foliosa are reported to form mycorrhizal associations. This is important in light of the invasion dynamics within San Francisco Bay-where Spartina hybrids are invading tidal habitats and causing functional changes in the ecosystem. Mycorrhizal associations can positively influence biomass production in invasive Spar tina and may contribute to increased invasion success. Of the Spartina hybrids investigated, 83% were mycorrhizal. During hybrid ization, the ability to be mycorrhizal may be contributed by the native S. foliosa, also found to be mycorrhizal, whereas the introduced S. alterniflora is non-mycorrhizal in its native habitat. Seedlings of Spartina hybrids inoculated with a commercial mycorrhizal mix showed greater above-ground growth and total biomass compared to control plants in the greenhouse. Mycorrhizal associations have the po-tential to influence the invasion trajectory of hybrid Spartina in San Francisco Bay, but additional research is needed. © Inter-Research 2011.