Abstract
Leedy’s roseroot (Rhodiola integrifolia subsp. leedyi) is a cliff-dwelling glacial relict federally-listed as threatened in the U.S. This research investigated abiotic and biotic factors correlated with Leedy’s roseroot at Glenora Cliffs, Glenora, NY. Results of censuses (2003-2015) showed decreased Leedy’s roseroot flowering in some sections of Glenora Cliffs. Abiotic factors correlated with Leedy’s roseroot occurrence included increased seepage, light, and summer temperatures, decreased weathering, and lower heights on the cliff. Analysis of the Glenora Cliffs community suggested Leedy’s roseroot co-occurs with other cliff-dwelling species. Experimental removal of Japanese knotweed (Fallopia japonica var. japonica) in a three-treatment block design revealed Japanese knotweed was associated with decreased flowering in Leedy’s roseroot. Herbicide removal of Japanese knotweed did not restore Leedy’s roseroot flowering, but was associated with increased temperature and light and shorter Leedy’s roseroot stems. Continued monitoring of Glenora Cliffs is recommended.