Meghan Avolio
Graduate Student
Department of Ecology and Evolutionary Biology
Yale University
OML 426
New Haven, CT 06511, USA
Email: meghanavolio@yale.edu
Education
2012 Ph.D. (expected) Yale University, Ecology and Evolutionary Biology
2006 M.S. Fordham University, Biology
2002 B.A. Barnard College of Columbia University, Environmental Biology
Meghan's CV
Current Research Interests
I am a plant ecologist who is broadly interested in plant communities and how they respond to multiple aspects of global change. During my graduate research, I have been studying the effects of more variable precipitation patterns on the genetic diversity of, Andropogon gerardii, a dominant tallgrass species, at Konza Prairie in Kansas. My research utilizes an on-going climate change experiment at Konza Prairie Biological Station, the Rainfall Manipulations Plots (RaMPs).
I have four objectives for my research:
- To assess the population structure of A. gerardii, and to infer the effects of genotypic diversity of this species for community and ecosystem properties.
- To investigate whether 10 years of altered rainfall patterns directly affects the genetic diversity of A. gerardii and if so, whether these changes have consequences for ecosystem function.
- To investigate whether there are phenotypic differences among genotypes both in the field and when grown under controlled greenhouse conditions. I have extensively studied an individual's phenotype from regulation of water-stress signaling cascades at the molecular level to growth and reproductive output.
- To determine whether genotypes have different sensitivities to either the size of a rainfall event or variability in timing between rainfall events. To address this last objective I performed a greenhouse experiment.
Previous Research
Nitrogen uptake and processing in a model ectohycorrizal fungus
In Germany I was working in Daniel Wipf's Group, Transport in Mycorrhizae, at Bonn University's Institute for Cellular and Molecular Botany. I developed a project studying all known nitrogen uptake and processing genes in the model ectomycorrhizal fungus Hebeloma cylindrosporum. I was interested in how carbon/nitrogen (C/N) ratio and N source of a substrate would interact to affect N uptake patterns by H. cylindrosporum. Specifically, I was testing the hypothesis that H. cylindrosporum growing on a low C/N ratio would be C-limited and would preferentially take up organic N sources, while H. cylindrosporum growing on a high C/N ratio be N-limited and would take up inorganic N sources preferentially. We found that on low C/N ratio, organic N transporter proteins were up-regulated relative to inorganic N transporter proteins. The reverse was not true, there was no difference between inorganic and organic N transporter proteins on the high C/N ratio, instead all N transporter proteins were up-regulated, suggesting the fungi were overall N-stressed.
Nitrogen deposition and ectomycorrihizal fungi
I received a Master’s degree from Fordham University working with Drs. Amy Tuininga and James Lewis specializing in both ecology and cellular biology. I designed my Master’s project to study the responses of ectomycorrhizal fungi to nitrogen deposition, both inorganic and organic forms. While the effects of inorganic N deposition on ectomycorrhizal communities has been well studied, little is known about the effects of organic N deposition. In a field experiment inorganic (ammonium and nitrate) and organic (glutamic acid) N sources were added to small plots in the New Jersey pine-barrens containing two bait seedlings, black oak and pitch pine. Our results show that ectomycorrhizal fungi responded positively to the organic N sources, while there was no response to the inorganic N sources. The host seedling also affected the response of the fungus to the N additions.
Publications
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Avolio, M, Müller, T, Mpangara, A, Fitz, M, Becker, B, Pauck, A, Kirsch, A, Wipf, D. Regulation of genes involved in nitrogen utilization on different C/N ratios and nitrogen sources in the model ectomycorrhizal fungus Hebeloma cylindrosporum. In press at Mycorrhiza.
- Müller T, Avolio M, Olivi M, Chalot M. and Wipf D. (2007). Organic nitrogen transport in the ectomycorrhiza on the basis of the Hebeloma cylindrosporum-Pinus pinaster association. Phytochemistry 68: 41-51.
- Müller T, Benjdia, M, Avolio, M, Voigt, B, Menzel, D, Pardo, A, Frommer W.B., and Wipf, D. (2006). Functional expression of the green fluorescent protein in the ectomycorrhizal model fungus Hebeloma cylindrosporum. Mycorrhiza, 16: 437-44.
Ersts, P., Pomilla, C., Kiszka, J., Cerchio, S., Rosenbaum, H.C., Vély, M., Razafindrakoto, Y., Loo, J.A., Leslie, M.S., and Avolio, M. 2011. Observations of individual humpback whales utilizing multiple migratory destinations in the southwestern Indian Ocean. African Journal of Marine Science 33: 333-338.
La Pierre, KJ, Yaun, S, Chang, CC, Avolio, ML, Hallett, LM, Schreck, T, Smith, MD. 2011. Explaining temporal variation in aboveground productivity in a mesic grassland: the role of climate and flowering. Journal of Ecology 99: 1250-1262.
Avolio, M, Chang, C, and Smith MD. 2011. Assessing the fine-scale genotypic structure of Andropogon gerardii in the tallgrass prairie. American Midland Naturalist 165: 211-224.
Avolio M, Tuininga A, Lewis, JD, and Marchese, M. (2009). Ectomycorrhizal Responses to Organic and Inorganic Nitrogen Sources When Associating with Two Host Species. Mycological Research 114: 897-907.