Whole tree excavation of 41 western juniper (Juniperus
occidentalis Hook.), ranging in age from 2 to 34 years old,
was used to assess the development and structure of root
systems, to determine biomass allocation patterns, and to
develop mathematical relationships for estimating biomass
and root system dimensions in seedling and...
Western juniper is a native species in eastern Oregon that became invasive during the last century since its range increased fivefold from 1936 to 1988. Western juniper’s ability to absorb rainfall and groundwater has deleterious effects on stream flow and sensitive sage grouse habitat in eastern Oregon. New methods of...
The rapid expansion of western juniper into neighboring plant communities during the past 130 years has caused considerable concern because of increased soil erosion, reduced stream
flows; reduced forage production; altered wildlife habitat; changes in plant community composition, structure, and biodiversity; and the replacement of mesic and semi-arid plant communities...
Patterns and costs of root/shoot allocations, response to reductions of above and below-ground tissue and to fertilization with nitrate and ammonium, and seasonal courses of physiological processes were measured on juvenile, small-adult, and large-adult Juniperus occidentalis growing in the field under ambient
environmental conditions in eastern Oregon.
Adult foliage had...
Understory species associations and their association with tree species were examined on three intensively studied stands. We studied the chronosequence of understory species associated with different aged singleleaf pinyon (Pinus monophylla Torr. and Frem.) trees. Mid- to late pinyon-juniper understory succession was found to be more spatial than floristic in...
Evidence suggests that western juniper
(Juniperus occidentalis) in Central Oregon affects
understory production and composition. As trees
increase in size and density, understory production is
reduced and composition changes. This study was
designed to identify the relationship between
production and composition of understory vegetation
and various tree canopy sizes of...
