Wound periderm formation in Juniperus occidentalis in response to Arceuthobium campylopodum

1980 ◽  
Vol 58 (3) ◽  
pp. 400-403 ◽  
Author(s):  
Annabelle E. Jaramillo
Keyword(s):  
Tissue Necrosis ◽  
Dwarf Mistletoe ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Periderm Formation ◽  
Host Tissues

Western juniper (Juniperus occidentalis) appears to resist infection by dwarf mistletoe (Arceuthobium campylopodum) with tissue necrosis and the formation of a wound periderm thereby restricting the penetrating structure of the parasite to peripheral host tissues.

Effects of fuel morphology on ember generation characteristics at the tree scale

2020 ◽  
Vol 29 (11) ◽  
pp. 1042
Author(s):  
Tyler R. Hudson ◽  
Ryan B. Bray ◽  
David L. Blunck ◽  
Wesley Page ◽  
Bret Butler
Keyword(s):  
Mass Loss ◽  
Pseudotsuga Menziesii ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Biological Factors ◽  
Abies Grandis ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Spot Fires

This work reports characteristics of embers generated by torching trees and seeks to identify the important physical and biological factors involved. The size of embers, number flux and propensity to ignite spot fires (i.e. number flux of ‘hot’ embers) are reported for several tree species under different combinations of number (one, three or five) and moisture content (11–193%). Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis), western juniper (Juniperus occidentalis) and ponderosa pine (Pinus ponderosa) trees were evaluated. Embers were collected on an array of fire-resistant fabric panels and trays filled with water. Douglas-fir trees generated the highest average ember flux per kilogram of mass loss during torching, whereas grand fir trees generated the highest ‘hot’ ember flux per kilogram of mass loss. Western juniper produced the largest fraction of ‘hot’ embers, with ~30% of the embers generated being hot enough to leave char marks. In contrast, only 6% of the embers generated by ponderosa pine were hot enough to leave char marks. Results from this study can be used to help understand the propensity of different species of tree to produce embers and the portion of embers that may be hot enough to start a spot fire.

scholarly journals Assessing the Carbon Consequences of Western Juniper (Juniperus occidentalis) Encroachment Across Oregon, USA

2012 ◽  
Vol 65 (3) ◽  
pp. 223-231 ◽  
Author(s):  
John L. Campbell ◽  
Robert E. Kennedy ◽  
Warren B. Cohen ◽  
Richard F. Miller
Keyword(s):  
Western Juniper ◽  
Juniperus Occidentalis

scholarly journals Utilization of the western juniper (Juniperus occidentalis) in strandboards to improve the decay resistance

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3886-3894
Author(s):  
Tomáš Pipíška ◽  
Jed Cappellazzi ◽  
Scott Leavengood ◽  
Frederick A. Kamke ◽  
Gerald Presley ◽  
...  
Keyword(s):  
Internal Bond ◽  
Brown Rot ◽  
White Rot ◽  
White Rot Fungus ◽  
Dry Density ◽  
Gloeophyllum Trabeum ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Yellow Pine ◽  
Southern Yellow Pine

Naturally durable wood species such as western juniper (Juniperus occidentalis) are a potential source of bio-based wood preservatives for the improvement of non-durable timber species. This research investigated the durability of southern yellow pine (Pinus sp.) and western juniper lumber or strandboard. Single layer panels were made with six different types of wood or wood treatments: southern yellow pine, mixed juniper sapwood and heartwood, sapwood, heartwood, sapwood strands impregnated with juniper oil prior to and after panel manufacturing. Panels were fabricated with 560 kg/m3 oven-dry density with 5% of PF resin and 0.5% of wax. Durability testing was performed with the brown rot fungi Gloeophyllum trabeum and Rhodonia placenta and the white rot fungus Trametes versicolor. Internal bond as a crucial parameter of OSB was measured. Tests revealed that juniper heartwood and juniper heartwood strandboards were highly decay resistant, and juniper oil pre- and post-impregnation strandboard manufacture imparted increased resistance to decay against one brown rot fungus, Gloeophyllum trabeum. Juniper strandboard manufactured from non-impregnated strands showed significantly higher internal bond than pine. These results suggest there is excellent potential for manufacturing highly decay-resistant OSB from juniper, especially from heartwood and that juniper oil can increase the durability of juniper sapwood strandboard.

Plant Succession Following Control of Western Juniper (Juniperus occidentalis) with Picloram

Weed Science ◽  
1985 ◽  
Vol 33 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Raymond A. Evans ◽  
James A. Young
Keyword(s):  
Total Yield ◽  
Plant Succession ◽  
Downy Brome ◽  
Herbaceous Vegetation ◽  
Dead Tree ◽  
Yield Increase ◽  
Litter Accumulation ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Tree Canopies

A 7-yr study was conducted to investigate successional dynamics of herbaceous vegetation after control of western juniper (Juniperus occidentalisHook.) trees with picloram (4-amino-3,5,6-trichloropicolinic acid) pellets. Downy brome (Bromus tectorumL. # BROTE) rapidly dominated areas under dead tree canopies with an accompanying yield increase from almost none to about 1400 kg/ha within 4 yr after treatment. In the interstitial zone between tree canopies, a dramatic shift in herbaceous species occurred with tree control. Annual broadleaf species decreased, downy brome increased, and medusahead [Taeniatherum asperum(Sim.) Nevski # ELYCM] gradually became dominant. Total yield of herbaceous vegetation in the interstitial zone increased dramatically after picloram treatment, especially where few shrubs occurred. Available soil moisture, litter accumulation and decay after picloram treatment, and N in the surface layer of the soil affected responses of herbaceous vegetation, especially under dead tree canopies. Responses of annual weedy species to western juniper control emphasize the need for comprehensive manipulation of all components of the vegetation when range improvement is attempted.

Weed Control and Revegetation Following Western Juniper (Juniperus occidentalis) Control

Weed Science ◽  
1985 ◽  
Vol 33 (4) ◽  
pp. 513-517 ◽  
Author(s):  
James A. Young ◽  
Raymond A. Evans ◽  
Carl Rimbey
Keyword(s):  
Weed Control ◽  
Herbaceous Species ◽  
Physical Restraints ◽  
Selective Predation ◽  
Wood Harvesting ◽  
Western Juniper ◽  
Juniperus Occidentalis ◽  
Dead Trees ◽  
Forage Species ◽  
Standing Dead

The control of western juniper (Juniperus occidentalisHook.) trees released shrub and herbaceous vegetation from dominance of the tree overstory. Revegetation of the woodland with desirable browse and forage species required weed control of both shrub and herbaceous species. The method of tree control (herbicidal, mechanical, or wood harvesting) influenced subsequent weed control-revegetation options in the understory. Physical restraints imposed by standing dead trees resulting from picloram (4-amino-3,5,6-trichloropicolinic acid) treatment limited the use of weed control and seeding equipment. Accumulation of litter interfered with the use of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] for annual grass control on both the picloram and wood harvest plots. Establishment of forage species was most successful on the mechanically cleared plots. Attempts to revegetate with browse species were largely foiled by native herbivores, and selective predation occurred on herbaceous species.

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