Community characteristics of old-growth western juniper woodlands
Issue Date
2001-09-01Keywords
eolian soilsterrain
tree age
seral stages
stand density
disturbed soils
stand structure
soil depth
ground cover
understory
climax communities
stand characteristics
sandy soils
species diversity
Juniperus occidentalis
slope
aspect
Oregon
plant communities
plant litter
botanical composition
canopy
soil texture
altitude
Juniperus occidentalis
structures
pinyon-juniper
Metadata
Show full item recordCitation
Waichler, W. S., Miller, R. F., & Doescher, P. S. (2001). Community characteristics of old-growth western juniper woodlands. Journal of Range Management, 54(5), 518-527.Publisher
Society for Range ManagementJournal
Journal of Range ManagementAdditional Links
https://rangelands.org/Abstract
While considerable attention has been given to the areal expansion of juniper (Juniperus sp.) in the western United States, the presence and ecological significance of old-growth juniper communities has gone largely unnoted. Increased recognition of these communities has prompted questions about how to recognize old-growth, community structure, ecological importance, and appropriate management. As an initial analysis of old-growth western juniper woodlands (Juniperus occidentalis Hook var. occidentalis Vasek) in central Oregon, this study investigated old-growth community structure on eolian-sand derived soils. These woodlands represent the most extensive old-growth western juniper woodlands throughout its range. Nine study plots were established at 7 sites. Within each plot, densities and physical attributes of all live trees and large standing and fallen woody detritus were recorded. Additional measurements for live trees included canopy cover, apparent age class (pre- or postsettlement), and a sampling of tree ages. Aging of trees older than 250 years was complicated by extensive heartwood rot. Shrub density and cover were measured by species. Understory cover was measured by species and functional type. Bare ground, rock, juniper litter, other litter, moss, and cryptogamic crust cover were also measured. Plant cover ranged from 11 to 33% for trees, 0 to 10% for shrubs, 3 to 12% for perennial grasses, 1 to 2% for forbs, and from 0 to 0.1% for annual grasses. The woodlands contained at least 80 trees ha(-1) aged over 200 years. Correlations between tree parameters and understory structure and composition were generally poor. Differences in plant composition among these stands was primarily attributed to elevation, slope, and percent sand content. Structural characteristics that distinguished old-growth stands from younger stands included tree growth form, presence of standing and dead large woody debris, lichen on dead branches, and a relatively open canopy. Results provide a preliminary basis for identifying old-growth Juniperus occidentalis stands, as a prelude to the development of management plans and further research into the functional characteristics of the systems. A definition of old-growth juniper woodlands is presented.Type
textArticle
Language
enISSN
0022-409Xae974a485f413a2113503eed53cd6c53
10.2307/4003580