Research Accomplishment Reports 2009

Endophyte Effects on the Structure and Function of Tall Fescue Pasture

R.L. McCulley
Department of Plant and Soil Sciences

 

Non-Technical Summary

Endophyte infection in tall fescue can cause significantly alter nutrient cycling and soil characteristics in pastures of the southeast. The purpose of this study is to evaluate the geographic range over which these endophyte effects are observed and to determine whether climate plays a role in governing these effects.

2009 Project Description

In 2009, activities performed included:

initiating a new field experiment entitled, Effects of Warming and Altered Precipitation Regime on Managed Grassland Structure and Function;

analyzing data from a global climate change and tall fescue project recently terminated at Oak Ridge National Labs;

and mentoring three graduate students.

Events that occurred were: 3 conferences (Ecological Society of America, Agronomy Society of America, and Southern Pasture & Forage Crop Improvement Conference), 1 field day, and 1 workshop (Southern Extension & Research Activity Information Exchange Group 8). Review services were provided for 3 proposals and 16 manuscripts.

Products included creating new collaborations and writing competitive grants on the general topic. I disseminated information on the topic of this KAES project through invited seminars (n=3) to college and university audiences, presentations at the above mentioned conferences, field days, and workshops, and communication with my College of Agriculture Press office and the Policy offices of the professional societies I have membership with.

2009 Impact

This project has contributed to several changes in knowledge. For example, we published a paper from this work that challenges the commonly held belief that fungal endophyte-produced alkaloids are the primary causative agent for endophyte-attributed ecological consequences in tall fescue systems, such as slowing rates of litter decomposition (Siegrist et al. 2009). In addition, some of my seminars on this topic have been received by undergraduate students, who have not thought about grass and/or the ecological consequences of symbiotic relationships. I have received feedback from these students, post my talk, along the lines of: who knew grass could be so interesting, and it's cool that such a small organism (the fungus) can have such a large impact. I have trained 4 graduate students to be competent scientists. I also taught 150 undergraduate students to identify fact, theories, and opinions in public press items related to agriculture that they read, with the ultimate goal of getting them to critically think about information presented to them on a daily basis.

2009 Publications

Siegrist, J.A., McCulley, R.L., Bush, L.P., and Phillips, T.D. 2009. Alkaloids may not be responsible for endophyte-associated reductions in tall fescue decomposition rates. Functional Ecology (in press).

McCulley, R.L., Brosi, G.B., and Nelson, J.A. 2009. Cool season, mixed species, forage response to nutrient additions. ASA-CSSA-SSSA Annual Meeting, Pittsburgh, PA. November, 2009.

Brosi, G.B, J.A. Nelson, R.L. McCulley, A.T. Classen, and R.J. Norby. 2009. Global change factors interact with fungal endophyte symbiosis to determine tall fescue litter chemistry. Ecological Society of America Annual Meeting, Albuquerque, NM. August, 2009.