- Ph.D. 1991, University of Missouri-Columbia
- Dendrochronology and tree ring chemistry.
- Guyette’s research involves the use of tree rings for monitoring tree growth and the environment. Currently he is working in several areas of dendrochronology. These include: determining pre-settlement fire frequency in oak-pine forests, reconstructing long-term climatic records from annual growth increments of eastern red cedar, and using calcium concentrations in tree rings as a transpiration variable.