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Keyword: western juniper

Fire regimes of juniper communities in the Columbia and northern Great basins

Publications Posted on: September 26, 2019
This synthesis summarizes information available in the scientific literature on historical patterns and contemporary changes in fuels and fire regimes in juniper communities of the Columbia and northern Great basins. Limited evidence suggests that many presettlement juniper woodlands and savannas had open stand structures, and they typically occurred in claypan soils or shallow soils on rocky sites.

Juniperus occidentalis

Publications Posted on: September 26, 2019
Western juniper occurs in the Pacific Northwest, California, and Nevada. Old-growth western juniper stands that established in presettlement times (before the 1870s) occur primarily on sites of low productivity such as claypan soils, rimrock, outcrops, the edges of mesas, and upper slopes. They are generally very open and often had sparse understories.

Response of conifer-encroached shrublands in the Great Basin to prescribed fire and mechanical treatments

Publications Posted on: July 14, 2015
In response to the recent expansion of pinon and juniper woodlands into sagebrush-steppe communities in the northern Great Basin region, numerous conifer-removal projects have been implemented, primarily to release understory vegetation at sites having a wide range of environmental conditions. Responses to these treatments have varied from successful restoration of native plant communities to complete conversion to nonnative invasive species.

Dynamics of western juniper woodland expansion into sagebrush communities in central Oregon

Publications Posted on: July 06, 2011
Western juniper (Juniperus occidentalis) woodlands in Oregon have expanded four-fold from 600,000 ha in 1930 to > 2.6 million ha, often resulting in the reduction and fragmentation of sagebrush (Artemisia spp.) communities. We documented dynamics of western juniper across the John Day Ecological Province in central Oregon by recording size class and growth form at 178 sites.

Combining a generic process-based productivity model classification method to predict the presence and absence species in the Pacific Northwest, U.S.A

Publications Posted on: November 29, 2010
Although long-lived tree species experience considerable environmental variation over their life spans, their geographical distributions reflect sensitivity mainly to mean monthly climatic conditions.We introduce an approach that incorporates a physiologically based growth model to illustrate how a half-dozen tree species differ in their responses to monthly variation in four climatic-related variables: water availability, deviations from an o

Characteristics of western juniper encroachment into sagebrush communities in central Oregon

Publications Posted on: November 18, 2009
Western juniper (Juniperus occidentalis) woodlands in Oregon have expanded four-fold from 600,000 ha in 1930 to > 2.6 million ha, often resulting in the reduction and fragmentation of sagebrush (Artemisia spp.) communities. We documented dynamics of western juniper across the John Day Ecological Province in central Oregon by recording size class and growth form at 178 sites.

Pinon and juniper field guide: Asking the right questions to select appropriate management actions

Publications Posted on: May 19, 2009
Pinon-juniper woodlands are an important vegetation type in the Great Basin. Old-growth and open shrub savanna woodlands have been present over much of the last several hundred years. Strong evidence indicates these woodlands have experienced significant tree infilling and major expansion in their distribution since the late 1800s by encroaching into surrounding landscapes once dominated by shrubs and herbaceous vegetation (fig. 1).

Fine-scale variation of historical fire regimes in sagebrush-steppe and juniper woodland: An example from California, USA

Publications Posted on: September 02, 2008
Coarse-scale estimates of fire intervals across the mountain big sagebrush (Artemisia tridentata spp. vaseyana (Rydb.) Beetle) alliance range from decades to centuries. However, soil depth and texture can affect the abundance and continuity of fine fuels and vary at fine spatial scales, suggesting fire regimes may vary at similar scales.

Age structure and expansion of pinon-juniper woodlands: a regional perspective in the Intermountain West

Publications Posted on: January 29, 2008
Numerous studies have documented the expansion of woodlands in the Intermountain West; however, few have compared the chronology of expansion for woodlands across different geographic regions or determined the mix and extent of presettlement stands. We evaluated tree age structure and establishment for six woodlands in four ecological provinces in the central and northern Great Basin.