Poster #20

The generality of specificity in plant-mycorrhizal interactions

T.W. D’ENTREMONT, S.N. KIVLIN
Department of Ecology and Evolutionary Biology, University of Tennessee, Dabney Hall 671, 1416 Circle Dr, Knoxville, TN 37996, USA

Species interactions exhibit varying degrees of specialization, ranging from generalist to specialist. For many interactions (e.g., plant-mycorrhiza) we lack standardized metrics of specialization, hindering our ability to apply comparative frameworks of specificity across niche axes and organismal groups. We explored the concept of plant host specificity of arbuscular mycorrhizal (AM) fungi. Using global co-occurrence data of arbuscular mycorrhizal species and plant host species, we tested taxonomic specificity and multiple categories of functional specificity. We found that although AM fungi are categorized as plant generalists, most AM fungi associate with few plant hosts. AM fungi showed high levels of specialization in nonvascular plants, gymnosperms and ferns but fewer specialist associations with angiosperms. Exotic plants showed higher levels of specialization than native and perennial plants had higher specificity than annuals. We emphasize the importance of analyzing global mycorrhizal data holistically to draw meaningful conclusions on symbiont interactions. We suggest a shift toward single-species analyses to unravel the complexities underlying these associations and predict how these mutualisms may affect plant invasions in a changing global climate.