An Eastern Redcedar and Rocky Mountain Juniper Provenance Test for Windbreak Suitability in Eastern South Dakota
Abstract Eastern redcedar and Rocky Mountain juniper are the two most commonly planted conifers east of the Black Hills in South Dakota. They are also planted in large numbers throughout the rest of the Great Plains. Despite their widespread use, practical genetic information for these species is limited. A regional provenance test of 118 eastern redcedar and 26 Rocky Mountain juniper sources was established in eastern South Dakota in 1980 to address this problem. Eastern redcedar exhibited better combinations of traits, with greater height growth, larger crown spread, a wider branch angle, and a stronger tendency toward producing a single terminal leader than Rocky Mountain juniper. Based on a windbreak suitability index the best performing seedlots collected from natural stands were all eastern redcedar from a large area of the central Great Plains. These results indicate that eastern redcedar should be favored over Rocky Mountain juniper for planting in eastern South Dakota. Sources of eastern redcedar south of central Kansas should be avoided. North. J. Appl. For. 5:129-132, June 1988.