Genetic variation in Great Plains Juniperus

Height growth was tallest and survival highest, at age 5, in Juniperus trees from seed sources of J. virginiana originating in the central Great Plains (east-central Nebraska, western Iowa, and east northcentral Kansas); and in trees from seed sources of J. scopulorum from northwest Nebraska and the High Plains (central to northeast Montana). Genotype x environment interaction in height was significant, but minimal in northern Great Plains plantations; it increased in the central plains plantations and primarily involved some southern sources. Agelage correlations indicated that selection of taller growing seed sources and taller trees within seed sources can be made at ages 2 and 5, respectively. Performance of Juniperus indicated an intermediate to broad adaptive mode.