Send to

Choose Destination
New Phytol. 2005 May;166(2):631-8.

Priority effects determine the outcome of ectomycorrhizal competition between two Rhizopogon species colonizing Pinus muricata seedlings.

Author information

Department of Integrative Biology, University of California, Berkeley, CA 94720, USA.


Competition is often considered a fundamental process influencing assemblage structure, yet little is known about competition among ectomycorrhizal (EM) fungi. Here, we examine competitive interactions between Rhizopogon occidentalis and Rhizopogon salebrosus in a 6-month microcosm study. Pinus muricata seedlings were grown in three EM treatments: R. occidentalis, R. salebrosus, and R. occidentalis and R. salebrosus. At 2, 4, and 6 months, five seedlings per treatment were harvested and the EM root tip biomass of each species was determined. Root tips in the two-species treatment were identified using molecular techniques. R. occidentalis had similar EM root tip biomass when grown alone or in the presence of R. salebrosus. By contrast, R. salebrosus had significantly lower EM root tip biomass when grown with R. occidentalis than when grown alone, indicating it was a competitive inferior under the conditions tested. Competition was driven by differences in timing of colonization resulting in a strong priority effect for R. occidentalis. Our results, together with two earlier studies, indicate competition may play a more important role in EM interactions than previously recognized.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center