His research involves the study of biological evolution, and particularly the application of molecular studies to elucidating the history of that evolution. His expertise lies both in the study of particular groups of plants and in the methodology used for those studies. Although he is one of the world's authorities on bamboo and grass evolution, he is best known for his work on identifying and analyzing DNA mutations. His publications have been cited more than 700 times with an average of 50 citations per paper. Kelchner has been published in top journals of evolutionary biology and has authored scientific papers about his discoveries and methods, which have contributed to an unusual 10 consecutive years of funding from the National Science Foundation (NSF). He is the principal investigator on $1.3 million in competitive research grants from the NSF.