Ectomycorrhizal Community of Red Oak at Harvard Forest 2013

There is evidence that ectomycorrhizal Pezizales prevail on roots at woodland edges or habitats where trees are well spaced, and where there is minimal understory vegetation, soil pH is relatively high, and bare soil is a feature. This observation was repeated in a recent study of mitospores produced by these fungi, where they were found most often at woodland edges, road sides, the middle of paths, and lawns. A key feature that distinguishes Basidiomycota from Ascomycota is that the dikaryon necessary for sexual reproduction is generally formed early after spore germination in the former, but not until fruitbody formation in the latter. Our hypothesis is that the mitospores produced by ectomycorrhizal Pezizales act as spermatia, and that these spores are more effectively produced and dispersed from bare soil than from areas with a thick organic layer. Here we tested our hypothesis by comparing the community of ectomycorrhizal root fungi on red oak trees in Harvard Forest and the Arnold Arboretum.