The Insect Microcosm of Western Juniper Berries

Abstract

Western juniper (Juniperus occidentalis) is a na- tive conifer found in eastern Oregon, north- eastern California, western Idaho, south- eastern Washington, and in small patches in northwestern Nevada. It has been expanding its range and increasing in density for over a century due to factors such as re suppression, grazing, and climate change.1 Although this species has expanded and contracted its range during past climate uctuations, the current expansion appears to be occurring more rapidly. Some of the issues associated with juniper expansion include the replacement and frag- mentation of important sagebrush steppe habitat, canopy

closure reducing availability of herbaceous understory plants to livestock and wildlife, and intense wild res that result in conversion to invasive annual grasslands. Extensive efforts have been made to remove western juniper and restore the shrublands being replaced. Management practices such as prescribed burning, mechanical removal (chaining, felling with chainsaws) and herbicides are used to thin or eliminate juniper in a given area. Despite the extensive literature de- tailing western juniper expansion, there are many aspects of its ecology that remain understudied, including interactions with seed predators and seed dispersers that are potentially important aspects of the ongoing expansion. Like other juni- per species, western juniper does not reproduce vegetatively (for example, by root sprouting), so this expansion is exclu- sively attributable to the establishment of new seedlings. Therefore, documenting the seed and seedling ecology of western juniper is essential to understanding the rapid ex- pansion of this species. 

DOI: 10.2458/azu_rangelands_v36i3_dimitri