Wildfire Occurrence in Aspen in the Interior Western United States

1987 ◽  
Vol 2 (3) ◽  
pp. 73-76 ◽  
Author(s):  
Norbert V. DeByle ◽  
Collin D. Bevins ◽  
William C. Fischer
Keyword(s):  
United States ◽  
Populus Tremuloides ◽  
Prescribed Fire ◽  
Western United States ◽  
National Forest ◽  
Quaking Aspen ◽  
Wildfire Occurrence ◽  
Management Intervention ◽  
Forest Lands

Abstract The western United States contains more than 7 million acres of quaking aspen (Populus tremuloides). On the majority of this acreage, aspen sprouted as even-aged stands after fires in the last 150 years. For several reasons, however, fire evidently is no longer playing its historic role of killing and regenerating western aspen stands. A survey was made of wildfire occurrence from 1970 through 1982 in aspen stands on National Forest lands in three Forest Service Regions. The survey data, expanded to include all aspen acreage, revealed that an average of 600 acres are annually consumed by fire. At this rate, it would require about 12,000 years to burn the entire aspen type in the West. During this time span, without management intervention, seral aspen will probably be replaced by conifers, and stable aspen stands may become all-aged and perhaps less productive. Use of prescribed fire is recommended. West. J. Appl. For. 2(3):73-76, July 1987.

Policy barriers and opportunities for prescribed fire application in the western United States

2019 ◽  
Vol 28 (11) ◽  
pp. 874 ◽  
Author(s):  
Courtney A. Schultz ◽  
Sarah M. McCaffrey ◽  
Heidi R. Huber-Stearns
Keyword(s):  
United States ◽  
Air Quality ◽  
Land Management ◽  
Prescribed Fire ◽  
Western United States ◽  
Management Tool ◽  
Major Barrier ◽  
Policy Barriers ◽  
Barriers And Opportunities

Prescribed fire is an important management tool on US federal lands that is not being applied at the necessary or desired levels. We investigated the role of policy barriers and opportunities for prescribed fire application on US Forest Service and Bureau of Land Management lands in the western United States. We conducted 54 semi-structured interviews with federal and state land managers and air quality regulators, and with several non-federal partners. We found that lack of adequate capacity and funding were the most commonly cited barriers to increasing application of prescribed fire. Interviewees also emphasised that owing to a lack of incentives and the prevalence of risk aversion at multiple agency levels, active prescribed fire programs depend on the leadership and commitment of individual decision-makers and fire managers. Successful approaches also rely on collaborative forums and positions that allow communication, problem-solving and resource sharing among federal and state partners, and that facilitate dialogue between air-quality and land managers. We did not find that air quality regulation was consistently cited as a major barrier, except in specific locations. Our findings highlight the importance of contextualised investigation into policy barriers and the role of collaborative and multilevel governance approaches for addressing complex land management challenges.

Microsatellite survey reveals possible link between triploidy and mortality of quaking aspen in Kaibab National Forest, Arizona

2015 ◽  
Vol 45 (10) ◽  
pp. 1369-1375 ◽  
Author(s):  
Groves B. Dixon ◽  
Laura E. DeWald
Keyword(s):  
United States ◽  
Environmental Factors ◽  
Microsatellite Markers ◽  
Populus Tremuloides ◽  
Ploidy Level ◽  
National Forest ◽  
Quaking Aspen ◽  
Predisposing Factor ◽  
Kaibab National Forest ◽  
Crown Dieback

In the southwestern United States, populations of quaking aspen (Populus tremuloides Michx.) are experiencing widespread mortality. Although environmental factors contributing to mortality have been well characterized, less is known about how genotype and particularly ploidy level affect susceptibility. We used five microsatellite markers to infer the ploidy level of 212 aspen stems in Kaibab National Forest, Arizona. Many multilocus genotypes showed three alleles at one or more loci, suggestive of frequent triploidy among our samples. Sites populated with putative triploids had higher mortality. In addition, heterozygosity was positively associated with mortality and crown dieback. Our results suggest that triploidy is a predisposing factor for aspen mortality in Kaibab National Forest.

scholarly journals Springtime high surface ozone events over the western United States: Quantifying the role of stratospheric intrusions

2012 ◽  
Vol 117 (D21) ◽  
pp. n/a-n/a ◽  
Author(s):  
Meiyun Lin ◽  
Arlene M. Fiore ◽  
Owen R. Cooper ◽  
Larry W. Horowitz ◽  
Andrew O. Langford ◽  
...  
Keyword(s):  
United States ◽  
Surface Ozone ◽  
High Surface ◽  
Western United States ◽  
Stratospheric Intrusions

scholarly journals A Landscape Approach to Aspen Restoration: Understanding the Role of Biophysical Setting in Aspen Community Dynamics

2002 ◽  
Vol 26 ◽  
pp. 97-102
Author(s):  
Kathryn Brown ◽  
Andrew Hansen ◽  
Robert Keane ◽  
Lisa Graumlich
Keyword(s):  
Populus Tremuloides ◽  
Community Dynamics ◽  
Rocky Mountain ◽  
Small Sample ◽  
Quaking Aspen ◽  
Climatic Fluctuations ◽  
Conifer Encroachment ◽  
Considerable Debate ◽  
Fire Exclusion

Considerable debate surrounds the persistence of quaking aspen (Populus tremuloides) communities in western North America. Loss of aspen cover has been documented in several studies in various Rocky Mountain ecosystems (Loope and Gruel 1973; Romme et al. 1995; Renkin and Despain 1996; Wirth et al. 1996; Baker et al. 1997; Kay 1997; Bartos and Campbell 1998; White et al. 1998; Gallant et al. 2003). Explanations for loss of aspen include conifer encroachment, fire exclusion, herbivory, and climatic fluctuations (Loope and Gruell 1973; Mueggler 1985; Bartos et al. 1994; Romme et al. 1995; Kay 1997; White et al. 1998). However, many studies documenting aspen decline have been geographically limited or based on a small sample of subjectively chosen stands (Barnett and Stohlgren 2001; Hessl 2002; Kaye et al. 2003).

Human ocular onchocerciasis caused by Onchocerca lupi (Spirurida, Onchocercidae) in Iran

2013 ◽  
Vol 88 (2) ◽  
pp. 250-255 ◽  
Author(s):  
G. Mowlavi ◽  
F. Farzbod ◽  
A. Kheirkhah ◽  
I. Mobedi ◽  
D.D. Bowman ◽  
...  
Keyword(s):  
United States ◽  
Sequence Analysis ◽  
Causative Agent ◽  
Ribosomal Dna ◽  
United States Of America ◽  
Clinical Signs ◽  
Western United States ◽  
Onchocerca Lupi ◽  
Nodular Lesions

AbstractCases of canine onchocerciasis caused by Onchocerca lupi are increasingly reported from Europe and the western United States of America. The zoonotic role of this parasite had already been suspected in Europe as the clinical signs and histopathology seen in two ocular cases from Albania and the Crimean region were very similar to those of canine ocular onchocerciasis. In the most recent reports of human onchocerciasis, O. lupi has been morphologically and molecularly identified as the causative agent of ocular infestation in two patients from Turkey, and one patient from Tunisia. Here, we report an additional case of nodular lesions involving two, and possibly more, immature worms in a patient from Iran. The parasite was found to belong to the genus Onchocerca based on morphological features and the species was confirmed as O. lupi from a partial sequence analysis of 12S ribosomal DNA.

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