Soils Lab

Jordan R. Mayor

Jordan R. Mayor

Current research

I am an ecosystem ecologist working in tropical rainforests of Panama as a National Science Foundation and Smithsonian Postdoctoral Research Fellow with Dr. Ben Turner.  My research aims to understand controls over foliar nitrogen isotope (δ15N) variability in trees so that we may use this integrative metric to understand subtle changes to nitrogen-cycles through time.  Recent δ15N-based research has shown that tropical forests are not immune to the effects of Nitrogen-deposition (Heitz et al. 2011).

My field sites are within natural and experimentally manipulated lowland and montane forest stands.  By examining the relationship between soil fertility and soil δ15N values I aim to constrain biogeochemical sources of plant δ15N variability.  By examining the role of species and nutrient acquisitions strategies I aim to discern if individual variability is greater than community level variability.  These questions will inform global interpretation of δ15N values as integrators of the nitrogen cycle worldwide and permit examination of nitrogen-based niche differentiation theory (John et al. 2007).

Past research

Previous research endeavors focused on the role of ectomycorrhizal fungi in shaping tropical forests of interior Guyana (Henkel et al. 2005, Mayor & Henkel 2006, Mayor et al. 2008, Fulgenzi et al. 2008) and led to an examination of global patterns in fungal isotope values (Mayor et al. 2009), a subject which I continue to work on.  During my PhD at University of Florida I focused on interpreting δ15N values in boreal black spruce forests of Alaska where I demonstrated that these trees are heavily dependent on organic nitrogen sources derived from their ectomycorrhizal hosts and used models to estimate nitrogen pathways, sources, and controls over annual productivity (Mayor et al. in review).


Hietz P., Turner B.L., Wanek W., Richter A., Nock C.A., Wright S.J. (2011) Long-term change in the nitrogen cycle of tropical forests Science 334: 664-666.

Mayor J.R., Schuur E.A.G., Henkel T.W. (2009) Elucidating the nutritional dynamics of fungi using stable isotopes. Ecology Letters 12: 171–183.

Mayor J.R., Fulgenzi T., Henkel T.W., Halling R.E. (2008) Boletellus piakaii sp. nov. and a new distribution record for Boletellus ananas var. ananas from Guyana. Mycotaxon 105: 387-398.

Fulgenzi T., Mayor J.R., Henkel T.W., Halling R.E. (2008) New species of Boletellus from Guyana. Mycologia 100: 490-495.

John R., Dalling J.W., Harms K.E., Yavitt J.B., Stallard R.F., Mirabello M., Hubbell S.P., Valencia R., Navarrete H., Vallejo M., Foster R.B. (2007) Soil nutrients influence spatial distributions of tropical tree species. Proceedings of the National Academy of Sciences 104: 864-869.

Mayor J.R., Henkel T.W. (2006) Do ectomycorrhizas alter leaf-litter decomposition in monodominant tropical forests of Guyana? New Phytologist 169: 579-588.

Henkel T.W., Mayor J.R., Woolley L. (2005) Mast fruiting and seedling survival of the ectomycorrhizal, monodominant Dicymbe corymbosa (Caesalpiniaceae) in Guyana. New Phytologist 167: 543-556.

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