Jeffrey pines

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. 

The recent history of the mixed-conifer forest of the San Bernardino Mountains has be n analyzed. This analysis included an initial inventory of ecosystem components and processes, as indicated in Figures 12-8 through 12-12. The inventory emphasizes ponderosa and Jeffrey pines, the most dominant species in the climax community, and is... 

The term ponderosa-Jeffrey type is a general term that includes a mosaic of five subtypes described by McBride on the basis of species dominance. These subtypes are ponderosa pine forest, ponderosa pine-white fir forest, ponderosa pine-Jefh y pine forest, Jeffry pine forest, and Jeffrey pine-white fir forest. The injury by oxidant air pollutants is most intense in the types dominated by ponderosa pine and less intense in the Jeffry pine types. In the field plots of these various types, the average area covered by shrubs is only 3.8% in the ponderosa types, but 26% in the Jeffrey pine types. ... 

Later studies have expressed the amount of injury to ponderosa and Jeffrey pines and associated tree species in permanent study plots as a numerical score. The range of scores is subdivided into seven categories ranging from dead to no visible symptoms. ... 

The genera] increase in injury in the severe and moderate plots is probably related to the 1974 increase in June-September dose (Figure 12-5). Tree mortality among ponderosa and Jeffrey pines was about the same in 1973 and 1974. The largest mortality was at permanent study plots in the moderate injury eatery. Perhaps the populations in these plots still retain greater numbers of the more susceptible genotypes. In earlier years, tree mortality rates for ponderosa or Je y pines in several stands suffering moderate to severe injury were 8% and 10%, respectively, from 1968 to 1972, 8% from 1969 to 1971, and 24% from 1966 to 1%9. The final cause of death of weakened trees is usually the pine bark beetle. Mortality has not been observed in tree species other than ponderosa and Jeffrey pine. 

FIGURE 12-14 Topographic projection, San Bernardino Mountains, showing how ponderosa pine (PP) and Jeffrey pine (JP) in major study sites are distributed in six injury classes according to seasonal dose of total oxidant. A, dead, 0 B, very severe, 1-8 C, severe, 9-14 D, moderate, 15-21 , slight, 22-28 F, very slight, 29-35 C, no visible damage, 36 +. Reprinted with permission from Kickert et al. 

TABLE 12-4 Changes of Timber Volume and Percentage of Total Jeffrey Pines in Four Insect Risk Qasses at Two Control Plots Excluded from Sanitation Salvage Logging between 1952 and 1972 at Barton Flats, San Bernardino National Forest... 

Needle length and litter production furnish another important measure of biomass decrease. In field studies, it was found that the average amount of litter production increased with decreasing ozone injuiy of selected ponderosa and Jeffrey pines (r - 0.55) and that the average mass of needles per fascicle increased with decreasing ozone injuiy (r = 0.%). ... 

The effects of sulfur dioxide on cone production have been described by Scheffer and Hedgcock and Pelz. Generally, the decrease in tree vigor caused by the pollutant may eliminate or lower the frequency of cone production and diminish the size, weight, and germination of seed. The effects of chronic ozone injury on conifer seed production may be similar, in that tree vigor is drastically reduced. The effects of chronic ozone injury on ponderosa and Jeffrey pine seed production are under investigation by Luck (in Kickert et al,... 

Wildfire is a very important factor in western forest ecosystems. In the San Bernardino Mountains, the fire frequencies were determined by McBride and Laven in two stand types before and after 1893, when the area was first set aside as a forest preserve and fire protection began. Before 1893, the average interval between fires in ponderosa stands was 12 yr after 1893, it was 24 yr. The comparable numbers for Jeffrey pine stands were 16 and 38 yr. The buildup of heavy fuels due to ozone-caused mortality and fire protection results in hotter fires, and the thinning of the tree canopy results in increased rates of fire spread. Hotter fires decrease tree survival. Moisture interception by condensation in living tree crowns would decrease as the stands became thinner, thus causing some sites to be drier. ... 

In the San Bernardino Mountains, our goals have been to describe the terrestrial vertebrate community within this mixed-conifer forest, particularly in relation to ponderosa and Jeffrey pine stands, and to determine the effects of oxidant air pollutants on this community. The possible interactions of vertebrates in this system are shown in Figures 12-8 through 12-12. 

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. 

In the San Bernardino Mountains, studies are going on to describe the effects of oxidant injury to ponderosa and Jeffrey pines on the microarthropods and fiingi of the litter layer under trees with various degrees of injury. Initial observations suggested lower population densities of microarthropods in the classes Insecta, Arachnida, and Myriapoda under some severely injured trees. ... 

It is well known that dogs track better in humid air. Rodents find buried seeds better in wet soil. This is important in arid climates. After rains, yellow pine chipmunks, Tamias amoenus, and deer mice, Peromyscus maniculatus found experimentally buried seeds of Jeffrey pine, Pinus jeffreyi, and antelope bitterbrush, Purshia tridentata, better than in diy soil. The recovered number of seeds increased 27- and 15-fold, respectively. In wet soil, seeds take up water rapidly and emanate volatile organic compounds that the rodents exploit. By extension, variations in humidity in arid environments may have profound effects on olfaction-dependent behaviors such as finding food, social interactions, preying, and predator avoidance (Vander Wall 1998). 

Other arabinogalactans from Jeffrey pine,132 jack pine,133 and white... 

Hall G. M., Tittiger C., Blomquist G. J., Andrews G., Mastick G., Barkawi L. A., Bengoa C. S. and Seybold S. J. (2002b) Male Jeffrey Pine Beetles, Dendroctonus jeffreyi, synthesize the pheromone component frontalin in anterior midgut tissue. Insect Biochem. Mol. Biol. 32, 1525-1532. 

Jeffrey pine beetle, Dendroctonus jeffreyi Hopkins, which had been previously treated with juvenile hormone III (JH III, 2.2 pg/beetle in acetone) and then placed in an aeration tube for 25 to 30 h. Ips paraconfusus and I. pini were each injected with 0.2 pCi of sodium [1-14C]acetate prior to placement in cut pine logs and volatile collection, while D. jeffreyi were each injected with 3.8 (male) and 3.7 (female) pCi of sodium [1-14C]acetate 6.4 (male) and 10.7 (female) h after JH application. (G) The role of the mevalonate pathway in frontalin biosynthesis is supported by the incorporation of radiolabel from [2-14C]mevalonolactone into frontalin by male D. jeffreyi (2.2 pg JH 11 l/beetle in acetone, 10 h incubation and volatile collection, 1.1 pCi of [2 14C] mevalonolactone injected, 20 h volatile collection). Figures adapted from Seybold et al. (1995b) and Barkawi (2002). 

Barkawi L. S. (2002) Biochemical and molecular studies of aggregation pheromones of bark beetles in the genus Dendroctonus (Coleoptera Scolytidae), with special reference to the Jeffrey pine beetle, Dendroctonus jeffreyi Hopkins. PhD thesis. Univ. Nevada, Reno, 193 pp. 

Paine T. D., Millar J. G., Hanlon C. C. and Hwang J.-S. (1999) Identification of semiochemicals associated with Jeffrey pine beetle, Dendroctonus jeffreyi. J. Chem. Ecol. 25, 433 153. 

Renwick J. A. A. and Pitman G. B. (1979) An attractant isolated from female Jeffrey pine beetles, Dendroctonus jeffreyi. Environ. Entomol. 8, 40-41. 

Tittiger C., O Keeffe C., Bengoa C. S., Barkawi L. S., Seybold S. J. et al. 2000. Isolation and endocrine regulation of an HMG-CoA synthase cDNAfrom the male Jeffrey pine beetle, Dendroctonus jejfreyi (Coleoptera Scolytidae). Insect Biochem. Molec. Biol. 30, 1203-1211. 

In 1969 an aerial photo survey by the U. S. Forest Service of the San Bernardino National Forest showed that 1.3 million ponderosa or Jeffrey pines (12 inches or larger, diameter at breast height) on more than 100,000 acres were affected to some degree (4). 

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