Incense cedar tree

A sesquiterpene has been isolated from the oil of the leaves and twigs f the Californian incense cedar tree, Lv.rocedrus decurrens, which has been named librocedrene. It has the following characters —... 

The incense cedar tree, native to California and Oregon, is used for the manufacture of pencils, fence posts, boarding, Venetian blinds, chests and toys. Cases of contact dermatitis have been described by Calnan (1972). Positive reactions were obtained with thymo-quinone (3-thujaplicin remained negative. Incense cedar contains up to 4% of thymoquinone (for structure, see Thuja plicata). 

Even that kind of information is not available for forest species. Other than chronic injury to white pine (associated with ozone, sulfur dioxide, and their mixtures), no clearly defined examples of chronic injury from ozone have been reported for eastern forests, and no information is available on PAN. It is of interest that both Virginia and jack pine appear more sensitive than white pine to acute ozone exposures, but chronic symptoms have not been observed in either species. The relationship between oxidant dose and injury in the San Bernardino Mountains area suggests that ponderosa pine is moderately to severely injured in areas that receive oxidant at above 0.08 ppm for 12-13 h each day (Chapter 12). Ponderosa pine seems to be the most sensitive western pine, but in some areas Jeffrey pine is about as sensitive. White fir, incense cedar, and sugar pine all appear more tolerant, even to the high oxidant concentrations in the San Bernardino Mountains. PAN may play some role in the chronic responses noted in the western forest species, particularly by broadleaf deciduous trees and some shrubs. 

Tree Size Gass Ponderosa Pine Incense Cedar White Fir Sugar Pine... 

California black oak and white fir and less often on incense cedar in the San Bernardino Mountains. No direct effects of oxidants have been noted on the mistletoe plant itself under field conditions. The true mistletoe obtains mainly water from its host and would be indirectly affected by debilitation of die host tree. The dwarf mistletoes Arceuthobium spp.) are common on ponderosa, Jeffry, and sugar pines in the San Bernardino National Forest. They depend on their host for both water and carbohydrates. Heavily infected or broomed" branches on ponderosa or Jeffrey pines severely injured by ozone often have more annual needle whorls retained than do uninfected branches on the remainder of the tree. The needles are also greener. It can be hypothesized that the infected branch is a carbohydrate sink where a pooling of carbohydrates occurs higher carbohydrate concentrations may be instrumental in either preventing or helping to repair ozone injury to needles on the broomed branches. In the long term, stresses from mistletoe and ozone are probably additive and hasten tree death. 

Species and Age Composition in Relation to Site. Combining all sites on the study area, the species composition in the understory (seedlings up through poles 11.99 inches dbh) is ponderosa pine, 22.2% incense cedar, 48.6% white fir, 22.8% and sugar pine, 6.3%. In the overstory (trees larger than 12.00 inches dbh) it is ponderosa, 49.6% incense cedar, 22.7% white fir, 19.7% and sugar pine, 8.0%. Table I shows the actual numbers in each size class. 

Survival and Competition in Early Growth Stages. The selective death of ponderosa pine in a conifer mixture with sugar pine, white fir, and incense cedar is an incident which directly affects other conifer species in the community. The conifer species compete with each other and with broad-leaved tree and shrub species for available light, soil moisture, nutrients, and space throughout their life span. 

On the upper one-third of the study area, which is a more windswept and severe site, there is already some indication that white fir does not grow well there. It is known that white fir is more subject to wind-throw than ponderosa pine (14). Perhaps sugar pine and incense cedar will make up a greater proportion of the future stand however, if natural regeneration is relied upon, the present supply of sugar pine seed trees is limited to only three per acre. Both species may have difficulty becoming established on the more barren, dry sites. 

Wood wastes do sometimes contain substances that are toxic to plants. In the studies with the 28 species of trees, Allison (1965) reported that most of the woods and barks were not toxic, but California incense cedar and white pine bark were very toxic to garden peas even at the rates of 1 and 2% added to soil in the presence of adequate nitrogen and lime. The woods of red cedar, Ponderosa pine, and loblolly pine, and the barks of California incense cedar and yellow poplar were slightly toxic at the 2-4% rates. The toxicity symptoms usually decreased with time during the two- to three-month period following addition to the soil. There have also been reports that a few other woods, such as walnut, hemlock, fir, and balsam are sometimes, but not always, toxic. Toxicity seems to vary with the age of the tree, and is also dependent upon the quantity added and the test plant. Decomposition time curves, reported by Allison, indicate that it is not uncommon for wood products to slightly retard early decomposition, apparently until the toxic materials disappear. The chemical nature of any toxic products present is not known with certainty but some investigators have attributed the toxicity to resins, turpentine and tannins. 

Librocedrus decurrens, a tree found in California and known as the Incense cedar, yields a leaf and tw oil and a bark oil. The leaf and twig oil has the following characters —... 

Perfume oil psychic correspondence wood woodbase for love incense for money and business, also for psychic work. For justice. Known in Lebanon as tree of power and longevity. Cedar (white) Thuja occidenlalis. 

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