Pluvial Occurrence of Bristlecone Pine (Pinus aristata) in a Mohave Desert Mountain Range

1969 ◽  
Vol 5 (4) ◽  
pp. 284 ◽  
Author(s):  
Peter J. Mehringer ◽  
Charles W. Ferguson
2012 ◽  
Vol 42 (1) ◽  
pp. 23-37 ◽  
Author(s):  
Anna W. Schoettle ◽  
Betsy A. Goodrich ◽  
Valerie Hipkins ◽  
Christopher Richards ◽  
Julie Kray

Pinus aristata Engelm., Rocky Mountain bristlecone pine, has a narrow core geographic and elevational distribution, occurs in disjunct populations, and is threatened by rapid climate change, white pine blister rust, and bark beetles. Knowledge of genetic diversity and population structure will help guide gene conservation strategies for this species. Sixteen sites across four mountain ranges in the core distribution of P. aristata were sampled and genetic diversity was assessed with 21 isozyme loci. Low species and population level genetic diversity (He = 0.070 and 0.062, respectively) occurred with moderate among-population differentiation (FST = 0.131). Genetic diversity correlated with longitude, latitude, and elevation and a strong mountain island effect may contribute to substructuring and isolation. Using multiple complementary analyses, sampled trees were assigned to three genetic lineages that varied in diversity and admixture and were associated with different climatic factors. The distribution of genetic diversity and substructuring of P. aristata may be an outcome of a combination of restricted gene flow due to geographic and phenological isolation, random processes of genetic drift, life history traits, natural selection, and postglacial migrations. The combination of low genetic diversity, moderate population isolation, and a protracted regeneration dynamic puts populations at risk for extirpation by novel stresses.


2015 ◽  
Vol 12 (2) ◽  
pp. 527-547 ◽  
Author(s):  
C. L. Faiola ◽  
B. T. Jobson ◽  
T. M. VanReken

Abstract. The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsuga menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate (MeJA), a herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC–MS–FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.


2007 ◽  
Vol 67 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Matthew W. Salzer ◽  
Malcolm K. Hughes

AbstractMany years of low growth identified in a western USA regional chronology of upper forest border bristlecone pine (Pinus longaeva and Pinus aristata) over the last 5000 yr coincide with known large explosive volcanic eruptions and/or ice core signals of past eruptions. Over the last millennium the agreement between the tree-ring data and volcano/ice-core data is high: years of ring-width minima can be matched with known volcanic eruptions or ice-core volcanic signals in 86% of cases. In previous millennia, while there is substantial concurrence, the agreement decreases with increasing antiquity. Many of the bristlecone pine ring-width minima occurred at the same time as ring-width minima in high latitude trees from northwestern Siberia and/or northern Finland over the past 4000–5000 yr, suggesting climatically-effective events of at least hemispheric scale. In contrast with the ice-core records, the agreement between widely separated tree-ring records does not decrease with increasing antiquity. These data suggest specific intervals when the climate system was or was not particularly sensitive enough to volcanic forcing to affect the trees, and they augment the ice core record in a number of ways: by providing confirmation from an alternative proxy record for volcanic signals, by suggesting alternative dates for eruptions, and by adding to the list of years when volcanic events of global significance were likely, including the mid-2nd-millennium BC eruption of Thera.


2014 ◽  
Vol 11 (9) ◽  
pp. 13455-13514 ◽  
Author(s):  
C. L. Faiola ◽  
B. T. Jobson ◽  
T. M. VanReken

Abstract. The largest global source of volatile organic compounds (VOCs) in the atmosphere is from biogenic emissions. Plant stressors associated with a changing environment can alter both the quantity and composition of the compounds that are emitted. This study investigated the effects of one global change stressor, increased herbivory, on plant emissions from five different coniferous species: bristlecone pine (Pinus aristata), blue spruce (Picea pungens), western redcedar (Thuja plicata), grand fir (Abies grandis), and Douglas-fir (Pseudotsugas menziesii). Herbivory was simulated in the laboratory via exogenous application of methyl jasmonate, an herbivory proxy. Gas-phase species were measured continuously with a gas chromatograph coupled to a mass spectrometer and flame ionization detector (GC-MS-FID). Stress responses varied between the different plant types and even between experiments using the same set of saplings. The compounds most frequently impacted by the stress treatment were alpha-pinene, beta-pinene, 1,8-cineol, beta-myrcene, terpinolene, limonene, and the cymene isomers. Individual compounds within a single experiment often exhibited a different response to the treatment from one another.


Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 469-481 ◽  
Author(s):  
Elizabeth K. Ralph ◽  
Henry N. Michael

This list is a continuation of Univ. of Pennsylvania Dates VII (Radiocarbon, 1965, v. 7, p. 179-186). It includes results for samples of Sequoia gigantea and for Pinus aristata, most of which were tree-ring dated at the Lab. of Tree-Ring Research, Univ. of Arizona.All sequoia and bristlecone pine samples have been corrected for deviations in C13/C12 ratios. The δC13 values listed represent the deviations (multiplied by 2) of the samples measured from the δC13 value of our 100-yr old standard oak sample which is also the reference value (adjusted for zero age) for the calculation of δC14. In our previous publication (Radiocarbon, 1965, v. 7, p. 179-186), δC13 values were erroneously reported as negative deviations from our oak standard. For the calculation of the Δ's, however, they were used in the correct sense. This mistake has been corrected in this list and one notes that the sequoias and bristlecone pines tend to be enriched slightly in C13 as compared with the oak standard.


Plant Disease ◽  
2004 ◽  
Vol 88 (3) ◽  
pp. 311-311 ◽  
Author(s):  
J. T. Blodgett ◽  
K. F. Sullivan

White pine blister rust caused by Cronartium ribicola was introduced into North America in the early 20th century and is spreading throughout the range of five-needle pines. In northern Colorado, this pathogen was first observed in 1998 on limber pine (Pinus flexilis) (1). It has not been reported on Rocky Mountain or Great Basin bristlecone pine (Pinus aristata and P. longaeva, respectively) in nature. However, Rocky Mountain bristlecone pine is susceptible to the disease when artificially inoculated (2). In October 2003, a Rocky Mountain bristlecone pine was found infected with C. ribicola in the Great Sand Dunes National Monument, Alamosa County, Colorado. Seven branch cankers were observed on the tree. Cankers ranged in length from 15 to 41 cm and were estimated to be approximately 5 to 7 years old. Distinct C. ribicola branch symptoms were observed, including flagging, spindle-shaped swellings, and 6 mm long aecial scars. A branch was deposited at the Colorado State Herbarium. Microscopic examination of spores within remnant aecial blisters revealed aeciospores characteristic of C. ribicola (yellow-orange, ellipsoid, verrucose, and 19 × 25 μm). Cankers were only observed on one bristlecone pine. However, most limber pines in the area were infected with C. ribicola, including a limber pine less than 1 m from the infected bristlecone pine. To our knowledge, this is the first report that shows Rocky Mountain bristlecone pine can become infected naturally, and the pathogen is further south in Colorado on limber pine than previously reported. These observations suggest the need for a more complete investigation of this disease on bristlecone pines. References: (1) D. W. Johnson and W. R. Jacobi. Plant Dis. 84:595, 2000. (2) B. R. Stephan, Allg. Forst Z. 28:695, 1985.


2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Barbara J. Bentz ◽  
E. Matthew Hansen ◽  
James C. Vandygriff ◽  
S. Sky Stephens ◽  
David Soderberg

When, in 1950, Willard Libby and his coworkers obtained their first radiocarbon ( 14 C) dates, C. W. Ferguson at the University of Arizona Tree Ring Laboratory was working on establishing a continuous tree ring series for the newly discovered bristlecone pine Pinus aristata . Before his untimely death in 1986, he had extended the series nearly 8000 years into the past. From the Ferguson series I obtained for 14 C determinations wood samples grown at various times. Also, two other laboratories obtained such samples. For B.C. times in particular, our measured 14 C-values that deviated consistently from those calculated from tree rings, and the deviations increased with age. This general trend was observed by other laboratories, but the presence of deviations from these trends, of the so-called ‘wiggles’, was questioned by other workers. To me these wiggles indicated the existence of a most interesting geophysical parameter valid for the whole terrestrial atmosphere. Fourier spectra obtained at my request by Kruse in 1972, and by Neftel, demonstrated the consistency of the results, and supported my contention that the secular variations of 14 C in atmospheric CO 2 are related to variations of solar activity.


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